Directeur de recherche (DR1 CNRS)
ENS – Département de chimie
24 rue Lhomond, 75005 Paris
Email: yong.chen@ens.psl.eu
Phone: +33 144322241
Office: E108
Understanding and regulating the natural systems at cellular levels is of particular interesting for disease modeling, drug screening, diagnosis and regenerative medicine. By developing consistently artificial basement membranes, microfluidic and pluripotent stem cell technologies, advanced in-vitro models of human tissues/organoids can be created, which mimic our sophisticated in-vivo systems.
Short bio
He received a B.S. degree in condensed matter physics from Wuhan University (1982) and both M.S. and Ph.D. degrees from the University of Montpelier (1983 and 1986). After spent three years at the Scuola Normale Superiorie di Pisa and Peking University, he joined the Centre National de Recherche Scientifique (CNRS) as Chargé de Recherche (1st class) in 1990 to work at the Laboratoire de Microstructures et de Microélectronique (L2M). In 1998, he became a Directeur de Recherche (2nd class) of CNRS. In 2003, he moved to the Ecole Normale Supérieure (ENS) as Professor and he is now Directeur de Recherche (1st class) of CNRS and head of the ENS team for microfluidics. In the past, he also served as Adjunct Professor at the Institute for Integrated Cell-Material Sciences (iCeMS) of Kyoto University, Changjiang Chair Professor of Peking University, Distinguished Chair Professor of Hong Kong Polytechnic University and Guess professor of Jianghan University.
Research interests
He has been worked in different fields, including semiconductor quantum heterostructures, photonic crystals, scanning near field optical microscopy, magnetic nanostructures, synchrotron based X-ray lithography, thermal and UV nanoimprint lithography, microfluidics, etc. His current interests are mainly in the field of biomedical research and applications such as cancer diagnosis and stem cell devices for in-vitro modeling of cardiac, neural and alveolar systems.
He has contributed to more than 500 scientific publications (peer-reviewed journals, book chapters and proceeding articles) and a large number of European and national research projects/networks. He is member of several international or national committees and reviewer of a number of journals. In total, he has supervised more than 50 Ph.D and post-doc studies.
Publications
2019 |
Substrate elasticity dependent colony formation and cardiac differentiation of human induced pluripotent stem cells Article de journal B Wang; X Tu; J Wei; L Wang; Y Chen Biofabrication, 11 (1), 2019. @article{Wang:2019, title = {Substrate elasticity dependent colony formation and cardiac differentiation of human induced pluripotent stem cells}, author = {B Wang and X Tu and J Wei and L Wang and Y Chen}, url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-85055623053&doi=10.1088%2f1758-5090%2faae0a5&partnerID=40&md5=ab6ecce73de3d9b0e276aac00a9123ac}, doi = {10.1088/1758-5090/aae0a5}, year = {2019}, date = {2019-01-01}, journal = {Biofabrication}, volume = {11}, number = {1}, abstract = {Substrate elasticity regulates cell functions including cell aggregation and stem cell differentiation. The ability to manufacture substrates of desired elasticity over a broad range is therefore crucial for both fundamental research and advanced applications. In this work, we developed a method to fabricate dense elastomer pillars of different heights on a rigid substrate, providing an effective elasticity ranging from 3 to 168 kPa. Assisted with an elastomer stencil of honeycomb pattern for cell seeding, we obtained uniform colonies of human induced pluripotent stem cells (hiPSCs) and differentiated cardiomyocytes on the pillar substrates of different modulus. Our results showed that the elasticity of substrates significantly affected the cell colony formation via governing the colony edge propagation. More importantly, the results demonstrated that an intermediate substrate elasticity of about 9 kPa is preferable to reach an embryoid-like aggregation and optimal for cardiac differentiation of hiPSCs. Overall, this work sheds new insights on the importance of substrate modulus on cell aggregation and stem cell differentiation as well as the manufacturing of culture substrates with desired elasticity. © 2018 IOP Publishing Ltd.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Substrate elasticity regulates cell functions including cell aggregation and stem cell differentiation. The ability to manufacture substrates of desired elasticity over a broad range is therefore crucial for both fundamental research and advanced applications. In this work, we developed a method to fabricate dense elastomer pillars of different heights on a rigid substrate, providing an effective elasticity ranging from 3 to 168 kPa. Assisted with an elastomer stencil of honeycomb pattern for cell seeding, we obtained uniform colonies of human induced pluripotent stem cells (hiPSCs) and differentiated cardiomyocytes on the pillar substrates of different modulus. Our results showed that the elasticity of substrates significantly affected the cell colony formation via governing the colony edge propagation. More importantly, the results demonstrated that an intermediate substrate elasticity of about 9 kPa is preferable to reach an embryoid-like aggregation and optimal for cardiac differentiation of hiPSCs. Overall, this work sheds new insights on the importance of substrate modulus on cell aggregation and stem cell differentiation as well as the manufacturing of culture substrates with desired elasticity. © 2018 IOP Publishing Ltd. |
2018 |
Synthesis and gas sensing properties of NiO/SnO2 hierarchical structures toward ppb-level acetone detection Article de journal J Hu; J Yang; W Wang; Y Xue; Y Sun; P Li; K Lian; W Zhang; L Chen; J Shi; Y Chen Materials Research Bulletin, 102 , p. 294–303, 2018. @article{Hu:2018a, title = {Synthesis and gas sensing properties of NiO/SnO2 hierarchical structures toward ppb-level acetone detection}, author = {J Hu and J Yang and W Wang and Y Xue and Y Sun and P Li and K Lian and W Zhang and L Chen and J Shi and Y Chen}, url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-85042636342&doi=10.1016%2fj.materresbull.2018.02.006&partnerID=40&md5=582fda1cf96adafef0d509dce74fcd80}, doi = {10.1016/j.materresbull.2018.02.006}, year = {2018}, date = {2018-01-01}, journal = {Materials Research Bulletin}, volume = {102}, pages = {294--303}, abstract = {We have synthesized pristine SnO2 and NiO/SnO2 hierarchical structures by a facile hydrothermal method. Structural and morphological characterizations of the obtained NiO/SnO2 samples were systematically studied using XRD, SEM, TEM and XPS. Meanwhile, gas-sensing properties of the as-fabricated pristine SnO2 and NiO/SnO2 sensor devices were investigated toward ppb-level acetone detection. The measured results show that the Ni1Sn3 gas sensor can reach a response of 20.18 toward 50 ppm acetone under optimum operating temperature (300 °C), which is about 3.3 times higher than that of pristine sensor. Moreover, the Ni1Sn3 gas sensor also exhibits fast response/recovery time (2 s/9 s), low detection limit (10 ppb) and good selectivity. We attribute the enhanced gas-sensing properties of NiO/SnO2 hierarchical structures to the synergetic effect as well as p-n heterojunction between the NiO and SnO2 structures. © 2018 Elsevier Ltd}, keywords = {}, pubstate = {published}, tppubtype = {article} } We have synthesized pristine SnO2 and NiO/SnO2 hierarchical structures by a facile hydrothermal method. Structural and morphological characterizations of the obtained NiO/SnO2 samples were systematically studied using XRD, SEM, TEM and XPS. Meanwhile, gas-sensing properties of the as-fabricated pristine SnO2 and NiO/SnO2 sensor devices were investigated toward ppb-level acetone detection. The measured results show that the Ni1Sn3 gas sensor can reach a response of 20.18 toward 50 ppm acetone under optimum operating temperature (300 °C), which is about 3.3 times higher than that of pristine sensor. Moreover, the Ni1Sn3 gas sensor also exhibits fast response/recovery time (2 s/9 s), low detection limit (10 ppb) and good selectivity. We attribute the enhanced gas-sensing properties of NiO/SnO2 hierarchical structures to the synergetic effect as well as p-n heterojunction between the NiO and SnO2 structures. © 2018 Elsevier Ltd |
TiO2 Nanorod Arrays with Mesoscopic Micro-Nano Interfaces for in Situ Regulation of Cell Morphology and Nucleus Deformation Article de journal H Liu; M Ruan; J Xiao; Z Zhang; C Chen; W Zhang; Y Cao; R He; Y Liu; Y Chen ACS Applied Materials and Interfaces, 10 (1), p. 66–74, 2018. @article{Liu:2018a, title = {TiO2 Nanorod Arrays with Mesoscopic Micro-Nano Interfaces for in Situ Regulation of Cell Morphology and Nucleus Deformation}, author = {H Liu and M Ruan and J Xiao and Z Zhang and C Chen and W Zhang and Y Cao and R He and Y Liu and Y Chen}, url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-85040347668&doi=10.1021%2facsami.7b11257&partnerID=40&md5=5bf996bc2e876997e737f8ece04d6048}, doi = {10.1021/acsami.7b11257}, year = {2018}, date = {2018-01-01}, journal = {ACS Applied Materials and Interfaces}, volume = {10}, number = {1}, pages = {66--74}, abstract = {Cell morphology and nucleus deformation are important when circulating tumor cells break away from the primary tumor and migrate to a distant organ. Cells are sensitive to the microenvironment and respond to the cell-material interfaces. We fabricated TiO2 nanorod arrays with mesoscopic micro-nano interfaces through a two-step hydrothermal reaction method to induce severe changes in cell morphology and nucleus deformation. The average size of the microscale voids was increased from 5.1 to 10.5 μm when the hydrothermal etching time was increased from 3 to 10 h, whereas the average distances between voids were decreased from 0.88 to 0.40 μm. The nucleus of the MCF-7 cells on the TiO2 nanorod substrate that was etched for 10 h exhibited a significant deformation, because of the large size of the voids and the small distance between voids. Nucleus defromation was reversible during the cells proliferate process when the cells were cultured on the mesoscopic micro-nano interface.This reversible process was regulated by combining of the uniform pressure applied by the actin cap and the localized pressure applied by the actin underneath the nucleus. Cell morphology and nucleus shape interacted with each other to adapt to the microenvironment. This mesoscopic micro-nano interface provided a new insight into the cell-biomaterial interface to investigate cell behaviors. © 2017 American Chemical Society.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Cell morphology and nucleus deformation are important when circulating tumor cells break away from the primary tumor and migrate to a distant organ. Cells are sensitive to the microenvironment and respond to the cell-material interfaces. We fabricated TiO2 nanorod arrays with mesoscopic micro-nano interfaces through a two-step hydrothermal reaction method to induce severe changes in cell morphology and nucleus deformation. The average size of the microscale voids was increased from 5.1 to 10.5 μm when the hydrothermal etching time was increased from 3 to 10 h, whereas the average distances between voids were decreased from 0.88 to 0.40 μm. The nucleus of the MCF-7 cells on the TiO2 nanorod substrate that was etched for 10 h exhibited a significant deformation, because of the large size of the voids and the small distance between voids. Nucleus defromation was reversible during the cells proliferate process when the cells were cultured on the mesoscopic micro-nano interface.This reversible process was regulated by combining of the uniform pressure applied by the actin cap and the localized pressure applied by the actin underneath the nucleus. Cell morphology and nucleus shape interacted with each other to adapt to the microenvironment. This mesoscopic micro-nano interface provided a new insight into the cell-biomaterial interface to investigate cell behaviors. © 2017 American Chemical Society. |
Fabrication of spaced monolayers of electrospun nanofibers for three-dimensional cell infiltration and proliferation Article de journal B Wang; L Wang; Y Tang; J Shi; J Wei; X Tu; Y Chen Microelectronic Engineering, 198 , p. 73–77, 2018. @article{Wang:2018, title = {Fabrication of spaced monolayers of electrospun nanofibers for three-dimensional cell infiltration and proliferation}, author = {B Wang and L Wang and Y Tang and J Shi and J Wei and X Tu and Y Chen}, url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-85050098757&doi=10.1016%2fj.mee.2018.07.005&partnerID=40&md5=84e7d65ac4697e672dd8261334cb19eb}, doi = {10.1016/j.mee.2018.07.005}, year = {2018}, date = {2018-01-01}, journal = {Microelectronic Engineering}, volume = {198}, pages = {73--77}, abstract = {Biophysical and biochemical properties of the extracellular matrix (ECM) are important for regulation of cell behaviors and tissue functions. In this study, we fabricated monolayers of gelatin nanofibers on both sides of a honeycomb micro-frame by electrospinning and chemical crosslinking, resulting in tri-layer patches with adjustable thickness and pore size. Fibroblast cells were cultured on this tri-layer scaffold, showing an enhanced cell proliferation. More importantly, our results showed an efficient cell infiltration into the space between the two fiber layers and 3D cell distribution suitable for cell based assays. © 2018}, keywords = {}, pubstate = {published}, tppubtype = {article} } Biophysical and biochemical properties of the extracellular matrix (ECM) are important for regulation of cell behaviors and tissue functions. In this study, we fabricated monolayers of gelatin nanofibers on both sides of a honeycomb micro-frame by electrospinning and chemical crosslinking, resulting in tri-layer patches with adjustable thickness and pore size. Fibroblast cells were cultured on this tri-layer scaffold, showing an enhanced cell proliferation. More importantly, our results showed an efficient cell infiltration into the space between the two fiber layers and 3D cell distribution suitable for cell based assays. © 2018 |
Electro-capture of heavy metal ions with carbon cloth integrated microfluidic devices Article de journal F -M Allioux; P Kapruwan; N Milne; L Kong; J Fattaccioli; Y Chen; L F Dumée Separation and Purification Technology, 194 , p. 26–32, 2018. @article{Allioux:2018, title = {Electro-capture of heavy metal ions with carbon cloth integrated microfluidic devices}, author = {F -M Allioux and P Kapruwan and N Milne and L Kong and J Fattaccioli and Y Chen and L F Dum\'{e}e}, url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-85034081895&doi=10.1016%2fj.seppur.2017.10.064&partnerID=40&md5=f886b8e021879892bb11615ac13e02d6}, doi = {10.1016/j.seppur.2017.10.064}, year = {2018}, date = {2018-01-01}, journal = {Separation and Purification Technology}, volume = {194}, pages = {26--32}, abstract = {A new multi-compartment microfluidic device was developed to simultaneously desalinate and recover valuable metal ions from aqueous streams mimicking metal plating and mining tailing wastewaters. Heavy and valuable metal ions including copper, zinc, nickel, silver and zinc/copper ionic mixtures were selectively transferred from the feed solution to a reduction chamber through ion-exchange membranes under the influence of an electrical field. A porous and conductive carbon cloth material was used as reduction platform, which led to improved desalination efficiencies, previously unachievable due to inevitable poisoning and degradation of the membranes at high current densities. The use of conductive carbon clothes enabled the recovery of the metal deposits, post reduction, through a simple electro-oxidation process. This novel microfluidic method, using ion-exchange materials as channel walls, has also the potential for the controlled decoration of materials with metal nanoparticle patterns and for the regeneration of rare earth trace contaminants by electro-sorption assisted electro-dialysis. © 2017 Elsevier B.V.}, keywords = {}, pubstate = {published}, tppubtype = {article} } A new multi-compartment microfluidic device was developed to simultaneously desalinate and recover valuable metal ions from aqueous streams mimicking metal plating and mining tailing wastewaters. Heavy and valuable metal ions including copper, zinc, nickel, silver and zinc/copper ionic mixtures were selectively transferred from the feed solution to a reduction chamber through ion-exchange membranes under the influence of an electrical field. A porous and conductive carbon cloth material was used as reduction platform, which led to improved desalination efficiencies, previously unachievable due to inevitable poisoning and degradation of the membranes at high current densities. The use of conductive carbon clothes enabled the recovery of the metal deposits, post reduction, through a simple electro-oxidation process. This novel microfluidic method, using ion-exchange materials as channel walls, has also the potential for the controlled decoration of materials with metal nanoparticle patterns and for the regeneration of rare earth trace contaminants by electro-sorption assisted electro-dialysis. © 2017 Elsevier B.V. |
Highly sensitive and ultra-fast gas sensor based on CeO2-loaded In2O3 hollow spheres for ppb-level hydrogen detection Article de journal J Hu; Y Sun; Y Xue; M Zhang; P Li; K Lian; S Zhuiykov; W Zhang; Y Chen Sensors and Actuators, B: Chemical, 257 , p. 124–135, 2018. @article{Hu:2018, title = {Highly sensitive and ultra-fast gas sensor based on CeO2-loaded In2O3 hollow spheres for ppb-level hydrogen detection}, author = {J Hu and Y Sun and Y Xue and M Zhang and P Li and K Lian and S Zhuiykov and W Zhang and Y Chen}, url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-85032892682&doi=10.1016%2fj.snb.2017.10.139&partnerID=40&md5=13fe2099e86c6930b924bf0287d673f5}, doi = {10.1016/j.snb.2017.10.139}, year = {2018}, date = {2018-01-01}, journal = {Sensors and Actuators, B: Chemical}, volume = {257}, pages = {124--135}, abstract = {H2 detection sensors based on pure and different contents of CeO2 (0.5 at%, 1 at%, 2 at%, 4 at%, 6 at%) loaded In2O3 hollow spheres were successfully fabricated. The crystal phase, morphology and chemical composition of the obtained CeO2-loaded In2O3 samples were analyzed by characteristic techniques. The gas sensing results showed that the CeO2-loaded In2O3 gas sensors exhibit enhanced H2 sensing performances compared with pure In2O3 at optimum working temperature (160 °C). Especially, the gas sensor based on 2 at% CeO2-loaded In2O3 hollow spheres showed most improved properties: highly response (20.7\textendash50 ppm) at 160 °C, which was about 3 times higher than that of pure In2O3 sensor (6.9); excellent response and recovery time of 1 s and 9 s; ultra-low detection of limit of 10 ppb; good repeatability and long-term stability. Finally, the enhanced gas sensing mechanism of CeO2-loaded In2O3 gas sensor towards H2 was also discussed. © 2017 Elsevier B.V.}, keywords = {}, pubstate = {published}, tppubtype = {article} } H2 detection sensors based on pure and different contents of CeO2 (0.5 at%, 1 at%, 2 at%, 4 at%, 6 at%) loaded In2O3 hollow spheres were successfully fabricated. The crystal phase, morphology and chemical composition of the obtained CeO2-loaded In2O3 samples were analyzed by characteristic techniques. The gas sensing results showed that the CeO2-loaded In2O3 gas sensors exhibit enhanced H2 sensing performances compared with pure In2O3 at optimum working temperature (160 °C). Especially, the gas sensor based on 2 at% CeO2-loaded In2O3 hollow spheres showed most improved properties: highly response (20.7–50 ppm) at 160 °C, which was about 3 times higher than that of pure In2O3 sensor (6.9); excellent response and recovery time of 1 s and 9 s; ultra-low detection of limit of 10 ppb; good repeatability and long-term stability. Finally, the enhanced gas sensing mechanism of CeO2-loaded In2O3 gas sensor towards H2 was also discussed. © 2017 Elsevier B.V. |
Fluorescent Determination of Glucose Using Silicon Nanodots Article de journal C Chen; Y Zhang; Z Zhang; R He; Y Chen Analytical Letters, 51 (18), p. 2895–2905, 2018. @article{Chen:2018, title = {Fluorescent Determination of Glucose Using Silicon Nanodots}, author = {C Chen and Y Zhang and Z Zhang and R He and Y Chen}, url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-85046704367&doi=10.1080%2f00032719.2018.1456547&partnerID=40&md5=c0f148d67d1ed8ca089caa3f618aa0d1}, doi = {10.1080/00032719.2018.1456547}, year = {2018}, date = {2018-01-01}, journal = {Analytical Letters}, volume = {51}, number = {18}, pages = {2895--2905}, abstract = {Here is reported a fluorescent biosensor for glucose detection based on water-soluble and pH-responsive silicon nanodots. The silicon nanodots were prepared using a facile hydrothermal method. The advantages of using the silicon nanodots as glucose sensor are twofold. Firstly, the fluorescence of silicon nanodots was quenched by hydrogen peroxide that was produced from glucose oxidation. Secondly, the fluorescence of silicon nanodots was highly sensitive to gluconic acid that was also produced by glucose oxidation. Our results show that this method detected glucose as low as 0.54 µM with a good selectivity and allowed the determination of glucose in serum samples. This method is also simple, rapid, low-toxic and low-cost, thereby hold high application potential for biological assays. © 2018, © 2018 Taylor & Francis.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Here is reported a fluorescent biosensor for glucose detection based on water-soluble and pH-responsive silicon nanodots. The silicon nanodots were prepared using a facile hydrothermal method. The advantages of using the silicon nanodots as glucose sensor are twofold. Firstly, the fluorescence of silicon nanodots was quenched by hydrogen peroxide that was produced from glucose oxidation. Secondly, the fluorescence of silicon nanodots was highly sensitive to gluconic acid that was also produced by glucose oxidation. Our results show that this method detected glucose as low as 0.54 µM with a good selectivity and allowed the determination of glucose in serum samples. This method is also simple, rapid, low-toxic and low-cost, thereby hold high application potential for biological assays. © 2018, © 2018 Taylor & Francis. |
Improved neuron culture using scaffolds made of three-dimensional PDMS micro-lattices Article de journal S Li; F P U Severino; J Ban; L Wang; G Pinato; V Torre; Y Chen Biomedical Materials (Bristol), 13 (3), 2018. @article{Li:2018b, title = {Improved neuron culture using scaffolds made of three-dimensional PDMS micro-lattices}, author = {S Li and F P U Severino and J Ban and L Wang and G Pinato and V Torre and Y Chen}, url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-85045760561&doi=10.1088%2f1748-605X%2faaa777&partnerID=40&md5=8789943ae2f084b9a2c910c247253b07}, doi = {10.1088/1748-605X/aaa777}, year = {2018}, date = {2018-01-01}, journal = {Biomedical Materials (Bristol)}, volume = {13}, number = {3}, abstract = {Tissue engineering strives to create functional components of organs with different cell types in vitro. One of the challenges is to fabricate scaffolds for three-dimensional (3D) cell culture under physiological conditions. Of particular interest is the investigation of the morphology and function of the central nervous system cultured using such scaffolds. Here, we used an elastomer - polydimethylsiloxane (PDMS) - to produce lattice-type scaffolds from a photolithography-defined template. The photomask with antidot arrays was spin-coated by a thick layer of resist, and was downward mounted on a rotating stage at an angle of 45. After the exposure was repeated three or more times, maintaining the same exposure plan but rotated by the same angle, a photoresist was developed to produce a 3D porous template. Afterwards, a pre-polymer mixture of PDMS was poured in and cured, followed by a resist etch, resulting in lattice-type PDMS features. Before cell culture, the PDMS lattices were surface functionalized. A culture test was conducted using NIH-3T3 cells and primary hippocampal cells from rats, showing homogenous cell infiltration and 3D attachment. As expected, a much higher cell number was found in the 3D PDMS lattices compared to the 2D culture. We also found a higher neuron-to-astrocyte ratio and a higher degree of cell ramification in the 3D culture compared to the 2D culture due to the change of scaffold topography and the elastic properties of the PDMS micro-lattices. Our results demonstrate that the 3D PDMS micro-lattices improve the survival and growth of cells, as well as the network formation of neurons. We believe that such an enabling technology is useful for research and clinical applications, including disease modeling, regenerative medicine, and drug discovery/drug cytotoxicity studies. © 2018 IOP Publishing Ltd.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Tissue engineering strives to create functional components of organs with different cell types in vitro. One of the challenges is to fabricate scaffolds for three-dimensional (3D) cell culture under physiological conditions. Of particular interest is the investigation of the morphology and function of the central nervous system cultured using such scaffolds. Here, we used an elastomer - polydimethylsiloxane (PDMS) - to produce lattice-type scaffolds from a photolithography-defined template. The photomask with antidot arrays was spin-coated by a thick layer of resist, and was downward mounted on a rotating stage at an angle of 45. After the exposure was repeated three or more times, maintaining the same exposure plan but rotated by the same angle, a photoresist was developed to produce a 3D porous template. Afterwards, a pre-polymer mixture of PDMS was poured in and cured, followed by a resist etch, resulting in lattice-type PDMS features. Before cell culture, the PDMS lattices were surface functionalized. A culture test was conducted using NIH-3T3 cells and primary hippocampal cells from rats, showing homogenous cell infiltration and 3D attachment. As expected, a much higher cell number was found in the 3D PDMS lattices compared to the 2D culture. We also found a higher neuron-to-astrocyte ratio and a higher degree of cell ramification in the 3D culture compared to the 2D culture due to the change of scaffold topography and the elastic properties of the PDMS micro-lattices. Our results demonstrate that the 3D PDMS micro-lattices improve the survival and growth of cells, as well as the network formation of neurons. We believe that such an enabling technology is useful for research and clinical applications, including disease modeling, regenerative medicine, and drug discovery/drug cytotoxicity studies. © 2018 IOP Publishing Ltd. |
2017 |
Synthesis and gas sensing properties of molybdenum oxide modified tungsten oxide microstructures for ppb-level hydrogen sulphide detection, Article de journal J Hu; Y Sun; X Wang; L Chen; W Zhang; Y Chen RSC Adv., 7 , p. 28542–28547, 2017. @article{hu2017synthesisb, title = {Synthesis and gas sensing properties of molybdenum oxide modified tungsten oxide microstructures for ppb-level hydrogen sulphide detection,}, author = {J Hu and Y Sun and X Wang and L Chen and W Zhang and Y Chen}, year = {2017}, date = {2017-01-01}, journal = {RSC Adv.}, volume = {7}, pages = {28542--28547}, keywords = {}, pubstate = {published}, tppubtype = {article} } |
Synthesis and characterization of flower-like MoO 3/In 2 O 3 microstructures for highly sensitive ethanol detection Article de journal J Hu; X Wang; M Zhang; YJ Sun; PW Li; WD Zhang; K Lian; L Chen; Y Chen RSC Adv., 7 , p. 23478–23485, 2017. @article{hu2017synthesis, title = {Synthesis and characterization of flower-like MoO 3/In 2 O 3 microstructures for highly sensitive ethanol detection}, author = {J Hu and X Wang and M Zhang and YJ Sun and PW Li and WD Zhang and K Lian and L Chen and Y Chen}, year = {2017}, date = {2017-01-01}, journal = {RSC Adv.}, volume = {7}, pages = {23478--23485}, keywords = {}, pubstate = {published}, tppubtype = {article} } |
Culture substrates made of elastomeric micro-tripod arrays for long-term expansion of human pluripotent stem cells Article de journal J Li; F Zhang; L Yu; N Fujimoto; M Yoshioka; X Li; J Shi; H Kotera; L Liu; Y Chen Journal of Materials Chemistry B, 5 (2), p. 236–244, 2017. @article{li2017culture, title = {Culture substrates made of elastomeric micro-tripod arrays for long-term expansion of human pluripotent stem cells}, author = {J Li and F Zhang and L Yu and N Fujimoto and M Yoshioka and X Li and J Shi and H Kotera and L Liu and Y Chen}, year = {2017}, date = {2017-01-01}, journal = {Journal of Materials Chemistry B}, volume = {5}, number = {2}, pages = {236--244}, publisher = {Royal Society of Chemistry}, keywords = {}, pubstate = {published}, tppubtype = {article} } |
Synthesis and gas sensing properties of molybdenum oxide modified tungsten oxide microstructures for ppb-level hydrogen sulphide detection Article de journal J Hu; Y Sun; X Wang; L Chen; W Zhang; Y Chen RSC Advances, 7 (45), p. 28542–28547, 2017. @article{Hu:2017, title = {Synthesis and gas sensing properties of molybdenum oxide modified tungsten oxide microstructures for ppb-level hydrogen sulphide detection}, author = {J Hu and Y Sun and X Wang and L Chen and W Zhang and Y Chen}, url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-85021693968&doi=10.1039%2fc7ra03864j&partnerID=40&md5=4f60f232ec98451ac270aadbcad29196}, doi = {10.1039/c7ra03864j}, year = {2017}, date = {2017-01-01}, journal = {RSC Advances}, volume = {7}, number = {45}, pages = {28542--28547}, abstract = {Flower-like molybdenum oxide@tungsten oxide (MoO3@WO3) composite microstructures were successfully synthesized by hydrothermal and impregnation methods. The fabricated samples were characterized by XRD, EDS, SEM and TEM, and the results show that the MoO3@WO3 composite is composed of crystallized nanosheets with a thickness of about 40 nm. The gas sensing properties of the MoO3@WO3 composite microstructures towards hydrogen sulfide (H2S) were investigated as a function of operating temperature and gas concentration. The gas sensors based on MoO3@WO3 composites show better sensing performances than that of a pure one. Moreover, the Mo6W-based gas sensor exhibits the highest response (28.5 towards 10 ppm H2S), fast response/recovery time (2 s/5 s), low detection limit (20 ppb) and good selectivity at optimum operating temperature (250 °C). Such an excellent performance can be attributed to the heterojunction between MoO3 and WO3. © 2017 The Royal Society of Chemistry.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Flower-like molybdenum oxide@tungsten oxide (MoO3@WO3) composite microstructures were successfully synthesized by hydrothermal and impregnation methods. The fabricated samples were characterized by XRD, EDS, SEM and TEM, and the results show that the MoO3@WO3 composite is composed of crystallized nanosheets with a thickness of about 40 nm. The gas sensing properties of the MoO3@WO3 composite microstructures towards hydrogen sulfide (H2S) were investigated as a function of operating temperature and gas concentration. The gas sensors based on MoO3@WO3 composites show better sensing performances than that of a pure one. Moreover, the Mo6W-based gas sensor exhibits the highest response (28.5 towards 10 ppm H2S), fast response/recovery time (2 s/5 s), low detection limit (20 ppb) and good selectivity at optimum operating temperature (250 °C). Such an excellent performance can be attributed to the heterojunction between MoO3 and WO3. © 2017 The Royal Society of Chemistry. |
Visible-light-controllable drug release from multilayer-coated microneedles Article de journal Z Zheng; H Ye; J Wang; T Zhang; Q You; H Li; R He; Y Chen; W Zhang; Y Cao Journal of Materials Chemistry B, 5 (34), p. 7014–7017, 2017. @article{Zheng:2017, title = {Visible-light-controllable drug release from multilayer-coated microneedles}, author = {Z Zheng and H Ye and J Wang and T Zhang and Q You and H Li and R He and Y Chen and W Zhang and Y Cao}, url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-85028619823&doi=10.1039%2fc7tb01546a&partnerID=40&md5=608c3752c37c46977e3ffea74c7f9eda}, doi = {10.1039/c7tb01546a}, year = {2017}, date = {2017-01-01}, journal = {Journal of Materials Chemistry B}, volume = {5}, number = {34}, pages = {7014--7017}, abstract = {A method for the generation of visible-light-controllable drug release polyelectrolyte multilayers on poly(l-lactide) (PLLA) microneedles is developed by host-guest chemistry. In response to visible light irradiation, model drugs encapsulated on polyelectrolyte multilayers transfer into the skin following brief microneedle application. © 2017 The Royal Society of Chemistry.}, keywords = {}, pubstate = {published}, tppubtype = {article} } A method for the generation of visible-light-controllable drug release polyelectrolyte multilayers on poly(l-lactide) (PLLA) microneedles is developed by host-guest chemistry. In response to visible light irradiation, model drugs encapsulated on polyelectrolyte multilayers transfer into the skin following brief microneedle application. © 2017 The Royal Society of Chemistry. |
Patch method for culture of primary hippocampal neurons Article de journal Y Tang; F P Ulloa Severino; F Iseppon; V Torre; Y Chen Microelectronic Engineering, 175 , p. 61–66, 2017. @article{Tang:2017, title = {Patch method for culture of primary hippocampal neurons}, author = {Y Tang and F P Ulloa Severino and F Iseppon and V Torre and Y Chen}, url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-85010204755&doi=10.1016%2fj.mee.2017.01.012&partnerID=40&md5=377f0d1b97130de4c5d7db431f7704c3}, doi = {10.1016/j.mee.2017.01.012}, year = {2017}, date = {2017-01-01}, journal = {Microelectronic Engineering}, volume = {175}, pages = {61--66}, abstract = {Culture of primary neurons, and especially hippocampal neurons, is important for understanding cellular mechanisms in neurobiology. Actually, this is achieved by using culture dish or glass slide with surface coated proteins. Here, we proposed a patch method for culture of primary neurons on a monolayer of gelatin nanofibers electrospun and crosslinked on a honeycomb microframe of poly (ethylene glycol) diacrylate (PEGDA). This method allows us to minimize exogenous material contact of cells and largely increase the exposure area of cells to the culture medium. We found that neurons, and especially astrocytes, have a more in vivo like morphology comparing to that on culture dish or on glass slide. We also found that neurons were preferentially located in the suspended areas of the monolayer nanofibers. Finally, calcium imaging revealed that primary neurons have a higher degree of neural activity on the patch than on glass. These results suggest that crosslinked and monolayer gelatin nanofibers closely mimic the extracellular matrix structure and allow more effective culture of primary neurons than conventional methods, thus facilitating advanced studies of neural functions as well as cell-based assays. © 2017}, keywords = {}, pubstate = {published}, tppubtype = {article} } Culture of primary neurons, and especially hippocampal neurons, is important for understanding cellular mechanisms in neurobiology. Actually, this is achieved by using culture dish or glass slide with surface coated proteins. Here, we proposed a patch method for culture of primary neurons on a monolayer of gelatin nanofibers electrospun and crosslinked on a honeycomb microframe of poly (ethylene glycol) diacrylate (PEGDA). This method allows us to minimize exogenous material contact of cells and largely increase the exposure area of cells to the culture medium. We found that neurons, and especially astrocytes, have a more in vivo like morphology comparing to that on culture dish or on glass slide. We also found that neurons were preferentially located in the suspended areas of the monolayer nanofibers. Finally, calcium imaging revealed that primary neurons have a higher degree of neural activity on the patch than on glass. These results suggest that crosslinked and monolayer gelatin nanofibers closely mimic the extracellular matrix structure and allow more effective culture of primary neurons than conventional methods, thus facilitating advanced studies of neural functions as well as cell-based assays. © 2017 |
Patterned parylene C for cell adhesion, spreading and alignment studies Article de journal X Tu; J Wei; B Wang; Y Tang; J Shi; Y Chen Microelectronic Engineering, 175 , p. 56–60, 2017. @article{Tu:2017, title = {Patterned parylene C for cell adhesion, spreading and alignment studies}, author = {X Tu and J Wei and B Wang and Y Tang and J Shi and Y Chen}, url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-85010216548&doi=10.1016%2fj.mee.2017.01.013&partnerID=40&md5=4df7b4a1b44ae05c50f72d36d42218a6}, doi = {10.1016/j.mee.2017.01.013}, year = {2017}, date = {2017-01-01}, journal = {Microelectronic Engineering}, volume = {175}, pages = {56--60}, abstract = {Parylene C is widely used for insulating coating of implantable medical devices due to its unique properties of biocompatibility and biostability. However, the interaction between cells and parylene C is limited with as-deposited samples. A plasma treatment of the sample can significantly improve the cell adhesion on parylene C. To further improve the cell adhesion as well as other cell functions, we patterned parylene C into pillars and stripes by soft lithography and chemical vapor deposition. Such a method is flexible to produce parylene C patterns on different surfaces. The fabricated substrates have been tested to culture Hela cells, showing much improved adhesion on pillar arrays of parylene C. Our results also showed a strong effect of contact guidance for cells on stripes of parylene C, thereby proving the relevance of the method for cell adhesion, spreading and alignment studies. © 2017 Elsevier B.V.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Parylene C is widely used for insulating coating of implantable medical devices due to its unique properties of biocompatibility and biostability. However, the interaction between cells and parylene C is limited with as-deposited samples. A plasma treatment of the sample can significantly improve the cell adhesion on parylene C. To further improve the cell adhesion as well as other cell functions, we patterned parylene C into pillars and stripes by soft lithography and chemical vapor deposition. Such a method is flexible to produce parylene C patterns on different surfaces. The fabricated substrates have been tested to culture Hela cells, showing much improved adhesion on pillar arrays of parylene C. Our results also showed a strong effect of contact guidance for cells on stripes of parylene C, thereby proving the relevance of the method for cell adhesion, spreading and alignment studies. © 2017 Elsevier B.V. |
Human Pluripotent Stem Cell-Derived Cardiac Tissue-like Constructs for Repairing the Infarcted Myocardium Article de journal J Li; I Minami; M Shiozaki; L Yu; S Yajima; S Miyagawa; Y Shiba; N Morone; S Fukushima; M Yoshioka; S Li; J Qiao; X Li; L Wang; H Kotera; N Nakatsuji; Y Sawa; Y Chen; L Liu Stem Cell Reports, 9 (5), p. 1546–1559, 2017. @article{Li:2017c, title = {Human Pluripotent Stem Cell-Derived Cardiac Tissue-like Constructs for Repairing the Infarcted Myocardium}, author = {J Li and I Minami and M Shiozaki and L Yu and S Yajima and S Miyagawa and Y Shiba and N Morone and S Fukushima and M Yoshioka and S Li and J Qiao and X Li and L Wang and H Kotera and N Nakatsuji and Y Sawa and Y Chen and L Liu}, url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-85032566653&doi=10.1016%2fj.stemcr.2017.09.007&partnerID=40&md5=15b6e5be763d02813d2fa8009b3e6859}, doi = {10.1016/j.stemcr.2017.09.007}, year = {2017}, date = {2017-01-01}, journal = {Stem Cell Reports}, volume = {9}, number = {5}, pages = {1546--1559}, abstract = {High-purity cardiomyocytes (CMs) derived from human induced pluripotent stem cells (hiPSCs) are promising for drug development and myocardial regeneration. However, most hiPSC-derived CMs morphologically and functionally resemble immature rather than adult CMs, which could hamper their application. Here, we obtained high-quality cardiac tissue-like constructs (CTLCs) by cultivating hiPSC-CMs on low-thickness aligned nanofibers made of biodegradable poly(D,L-lactic-co-glycolic acid) polymer. We show that multilayered and elongated CMs could be organized at high density along aligned nanofibers in a simple one-step seeding process, resulting in upregulated cardiac biomarkers and enhanced cardiac functions. When used for drug assessment, CTLCs were much more robust than the 2D conventional control. We also demonstrated the potential of CTLCs for modeling engraftments in vitro and treating myocardial infarction in vivo. Thus, we established a handy framework for cardiac tissue engineering, which holds high potential for pharmaceutical and clinical applications. Although high-purity cardiomyocytes can be achieved, they are randomly distributed and resemble immature rather than adult CMs. In this article, Liu Li and her colleagues show that 3D and aligned cardiac tissue-like constructs (CTLCs) can be obtained using hPSC-CMs and aligned nanofiber. They also demonstrate the robust drug responses and repair capability of CTLCs in a myocardial infarction model. © 2017 The Authors}, keywords = {}, pubstate = {published}, tppubtype = {article} } High-purity cardiomyocytes (CMs) derived from human induced pluripotent stem cells (hiPSCs) are promising for drug development and myocardial regeneration. However, most hiPSC-derived CMs morphologically and functionally resemble immature rather than adult CMs, which could hamper their application. Here, we obtained high-quality cardiac tissue-like constructs (CTLCs) by cultivating hiPSC-CMs on low-thickness aligned nanofibers made of biodegradable poly(D,L-lactic-co-glycolic acid) polymer. We show that multilayered and elongated CMs could be organized at high density along aligned nanofibers in a simple one-step seeding process, resulting in upregulated cardiac biomarkers and enhanced cardiac functions. When used for drug assessment, CTLCs were much more robust than the 2D conventional control. We also demonstrated the potential of CTLCs for modeling engraftments in vitro and treating myocardial infarction in vivo. Thus, we established a handy framework for cardiac tissue engineering, which holds high potential for pharmaceutical and clinical applications. Although high-purity cardiomyocytes can be achieved, they are randomly distributed and resemble immature rather than adult CMs. In this article, Liu Li and her colleagues show that 3D and aligned cardiac tissue-like constructs (CTLCs) can be obtained using hPSC-CMs and aligned nanofiber. They also demonstrate the robust drug responses and repair capability of CTLCs in a myocardial infarction model. © 2017 The Authors |
Fabrication of PLGA nanofibers on PDMS micropillars for neuron culture studies Article de journal J Wei; D Pozzi; F P Ulloa Severino; V Torre; Y Chen Microelectronic Engineering, 175 , p. 67–72, 2017. @article{Wei:2017, title = {Fabrication of PLGA nanofibers on PDMS micropillars for neuron culture studies}, author = {J Wei and D Pozzi and F P Ulloa Severino and V Torre and Y Chen}, url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-85012237643&doi=10.1016%2fj.mee.2017.01.015&partnerID=40&md5=670a0df151504e4269131aaf6649b37e}, doi = {10.1016/j.mee.2017.01.015}, year = {2017}, date = {2017-01-01}, journal = {Microelectronic Engineering}, volume = {175}, pages = {67--72}, abstract = {We fabricated a nanocomposite substrate made of nanofibers on micropillar arrays by photolithography, soft lithography and electrospinning for cell culture studies. This nanocomposite substrate combines the advantage of the extra-cellular matrix (ECM)-like surface morphology and high porosity and low stiffness of underneath supporting material. For neuronal culture studies, we used nanofibers of poly (lactic-co-glycolic acid) (PLGA) on high aspect ratio micropillars of polydimethylsiloxane (PDMS). Our results showed that primary hippocampal neurons on such a nanocomposite substrate have different cell morphology than on flat surfaces and they showed more electric activities. Thus, the nanofiber-micropillar composite substrates were shown to be useful for neuron culture studies. © 2017}, keywords = {}, pubstate = {published}, tppubtype = {article} } We fabricated a nanocomposite substrate made of nanofibers on micropillar arrays by photolithography, soft lithography and electrospinning for cell culture studies. This nanocomposite substrate combines the advantage of the extra-cellular matrix (ECM)-like surface morphology and high porosity and low stiffness of underneath supporting material. For neuronal culture studies, we used nanofibers of poly (lactic-co-glycolic acid) (PLGA) on high aspect ratio micropillars of polydimethylsiloxane (PDMS). Our results showed that primary hippocampal neurons on such a nanocomposite substrate have different cell morphology than on flat surfaces and they showed more electric activities. Thus, the nanofiber-micropillar composite substrates were shown to be useful for neuron culture studies. © 2017 |
Integrated heart/cancer on a chip to reproduce the side effects of anti-cancer drugs: In vitro Article de journal K -I Kamei; Y Kato; Y Hirai; S Ito; J Satoh; A Oka; T Tsuchiya; Y Chen; O Tabata RSC Advances, 7 (58), p. 36777–36786, 2017. @article{Kamei:2017, title = {Integrated heart/cancer on a chip to reproduce the side effects of anti-cancer drugs: In vitro}, author = {K -I Kamei and Y Kato and Y Hirai and S Ito and J Satoh and A Oka and T Tsuchiya and Y Chen and O Tabata}, url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-85026422574&doi=10.1039%2fc7ra07716e&partnerID=40&md5=13ea3a5eaa6f8ede4efd195731a15564}, doi = {10.1039/c7ra07716e}, year = {2017}, date = {2017-01-01}, journal = {RSC Advances}, volume = {7}, number = {58}, pages = {36777--36786}, abstract = {Pre-clinical animal tests are used to assess drug efficacy and safety, but are limited by factors such as their suitability as a model for humans, robustness, cost, and ethical issues. While an organ-on-a-chip using human cells is promising for recapitulating human physiological conditions, it is highly desirable in investigations of the side effects of drugs to integrate more than one type of tissue using a designed circulatory system. We have developed a microfluidic device - an Integrated Heart/Cancer on a Chip (iHCC) - using human healthy heart cells (hCMs) and liver cancer cells (HepG2) to recapitulate the side effects of an anti-cancer drug, doxorubicin (DXR), to achieve individual cultures of cells from different tissues on a single device with three sets of artificial blood circulation loops, microfabrication technology for micro valves and a pump provides accurate fluid operation. Using improved soft lithography adopting numerical optimization simulation, the microfluidic device was fabricated with on-chip integration of pneumatic valves and a peristaltic micropump establishing precision fluid flow. The iHCC developed allows modelling of the side effects of DXR on heart cells caused by the production of toxic metabolites (doxorubicinol; DXRol) by HepG2 cells and the delivery of DXRol to heart cells via the circulation loop. Our findings open the door towards the development of a "Body-on-a-Chip." © 2017 The Royal Society of Chemistry.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Pre-clinical animal tests are used to assess drug efficacy and safety, but are limited by factors such as their suitability as a model for humans, robustness, cost, and ethical issues. While an organ-on-a-chip using human cells is promising for recapitulating human physiological conditions, it is highly desirable in investigations of the side effects of drugs to integrate more than one type of tissue using a designed circulatory system. We have developed a microfluidic device - an Integrated Heart/Cancer on a Chip (iHCC) - using human healthy heart cells (hCMs) and liver cancer cells (HepG2) to recapitulate the side effects of an anti-cancer drug, doxorubicin (DXR), to achieve individual cultures of cells from different tissues on a single device with three sets of artificial blood circulation loops, microfabrication technology for micro valves and a pump provides accurate fluid operation. Using improved soft lithography adopting numerical optimization simulation, the microfluidic device was fabricated with on-chip integration of pneumatic valves and a peristaltic micropump establishing precision fluid flow. The iHCC developed allows modelling of the side effects of DXR on heart cells caused by the production of toxic metabolites (doxorubicinol; DXRol) by HepG2 cells and the delivery of DXRol to heart cells via the circulation loop. Our findings open the door towards the development of a "Body-on-a-Chip." © 2017 The Royal Society of Chemistry. |
2016 |
Nanometric emulsions encapsulating solid particles as alternative carriers for intracellular delivery Article de journal S Quignard; G Frébourg; Y Chen; J Fattaccioli Nanomedicine, 11 (16), p. 2059–2072, 2016. @article{Quignard:2016, title = {Nanometric emulsions encapsulating solid particles as alternative carriers for intracellular delivery}, author = {S Quignard and G Fr\'{e}bourg and Y Chen and J Fattaccioli}, url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-84982187341&doi=10.2217%2fnnm-2016-0074&partnerID=40&md5=d5c188ca60865d1645effd2e9f970a91}, doi = {10.2217/nnm-2016-0074}, year = {2016}, date = {2016-01-01}, journal = {Nanomedicine}, volume = {11}, number = {16}, pages = {2059--2072}, abstract = {Aim: Formulate nanometric oil droplets for encapsulating solid nanoparticles and assess their interactions with cells. Materials & methods: Soybean oil droplets, stabilized by Pluronic F68 surfactant, incorporating hydrophobically modified fluorescent silica, nanoparticles were obtained. Cytotoxicity over time, internalization, subsequent intracellular localization and internalization pathways were assessed by microscopy (fluoresence and TEM) in vitro with HeLa cells. Results: Oil droplets encapsulating solid nanoparticles are readily internalized by HeLa cells like free nanoparticles but the intracellular localization differs (nanoemulsions less colocalized with lysosomes) as well as internalization pathway is used (nanoemulsions partially internalized by nonendocytic transport). No cytotoxicity could be observed for either particles tested. Conclusion: Our results confirm that nanometric emulsions encapsulating solid nanoparticles can be used for alternative and multifunctional intracellular delivery. © 2016 Future Medicine Ltd.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Aim: Formulate nanometric oil droplets for encapsulating solid nanoparticles and assess their interactions with cells. Materials & methods: Soybean oil droplets, stabilized by Pluronic F68 surfactant, incorporating hydrophobically modified fluorescent silica, nanoparticles were obtained. Cytotoxicity over time, internalization, subsequent intracellular localization and internalization pathways were assessed by microscopy (fluoresence and TEM) in vitro with HeLa cells. Results: Oil droplets encapsulating solid nanoparticles are readily internalized by HeLa cells like free nanoparticles but the intracellular localization differs (nanoemulsions less colocalized with lysosomes) as well as internalization pathway is used (nanoemulsions partially internalized by nonendocytic transport). No cytotoxicity could be observed for either particles tested. Conclusion: Our results confirm that nanometric emulsions encapsulating solid nanoparticles can be used for alternative and multifunctional intracellular delivery. © 2016 Future Medicine Ltd. |
On-chip quantitative measurement of mechanical stresses during cell migration with emulsion droplets Article de journal D Molino; S Quignard; C Gruget; F Pincet; Y Chen; M Piel; J Fattaccioli Scientific reports, 6 (1), p. 1–11, 2016. @article{molino2016chip, title = {On-chip quantitative measurement of mechanical stresses during cell migration with emulsion droplets}, author = {D Molino and S Quignard and C Gruget and F Pincet and Y Chen and M Piel and J Fattaccioli}, year = {2016}, date = {2016-01-01}, journal = {Scientific reports}, volume = {6}, number = {1}, pages = {1--11}, publisher = {Nature Publishing Group}, keywords = {}, pubstate = {published}, tppubtype = {article} } |
On-chip quantitative measurement of mechanical stresses during cell migration with emulsion droplets Article de journal D Molino; S Quignard; C Gruget; F Pincet; Y Chen; M Piel; J Fattaccioli Scientific Reports, 6 , 2016. @article{Molino:2016, title = {On-chip quantitative measurement of mechanical stresses during cell migration with emulsion droplets}, author = {D Molino and S Quignard and C Gruget and F Pincet and Y Chen and M Piel and J Fattaccioli}, url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-84977554652&doi=10.1038%2fsrep29113&partnerID=40&md5=4440380967afde5b7409cabda3050682}, doi = {10.1038/srep29113}, year = {2016}, date = {2016-01-01}, journal = {Scientific Reports}, volume = {6}, abstract = {The ability of immune cells to migrate within narrow and crowded spaces is a critical feature involved in various physiological processes from immune response to metastasis. Several in-vitro techniques have been developed so far to study the behaviour of migrating cells, the most recent being based on the fabrication of microchannels within which cells move. To address the question of the mechanical stress a cell is able to produce during the encounter of an obstacle while migrating, we developed a hybrid microchip made of parallel PDMS channels in which oil droplets are sparsely distributed and serve as deformable obstacles. We thus show that cells strongly deform droplets while passing them. Then, we show that the microdevice can be used to study the influence of drugs on migration at the population level. Finally, we describe a quantitative analysis method of the droplet deformation that allows measuring in real-time the mechanical stress exerted by a single cell. The method presented herein thus constitutes a powerful analytical tool for cell migration studies under confinement.}, keywords = {}, pubstate = {published}, tppubtype = {article} } The ability of immune cells to migrate within narrow and crowded spaces is a critical feature involved in various physiological processes from immune response to metastasis. Several in-vitro techniques have been developed so far to study the behaviour of migrating cells, the most recent being based on the fabrication of microchannels within which cells move. To address the question of the mechanical stress a cell is able to produce during the encounter of an obstacle while migrating, we developed a hybrid microchip made of parallel PDMS channels in which oil droplets are sparsely distributed and serve as deformable obstacles. We thus show that cells strongly deform droplets while passing them. Then, we show that the microdevice can be used to study the influence of drugs on migration at the population level. Finally, we describe a quantitative analysis method of the droplet deformation that allows measuring in real-time the mechanical stress exerted by a single cell. The method presented herein thus constitutes a powerful analytical tool for cell migration studies under confinement. |
Luminescent and absorptive metal-coated emulsions for micro-velocimetry Article de journal O Mesdjian; Y Chen; J Fattaccioli Microelectronic Engineering, 158 , p. 69–74, 2016. @article{Mesdjian:2016, title = {Luminescent and absorptive metal-coated emulsions for micro-velocimetry}, author = {O Mesdjian and Y Chen and J Fattaccioli}, url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-84978884079&doi=10.1016%2fj.mee.2016.03.028&partnerID=40&md5=2b9a565a85f93eac435dcd7cdbc78fe4}, doi = {10.1016/j.mee.2016.03.028}, year = {2016}, date = {2016-01-01}, journal = {Microelectronic Engineering}, volume = {158}, pages = {69--74}, abstract = {Fluorescent latex beads have been widely used as tracers in microfluidics for the last decades. They have the advantages to be density matched with water and to be easily localizable using fluorescence microscopy. We have recently synthesized silver-coated oil droplets that are both luminescent and absorptive, by first coating the oil interface with a polydopamine layer and then depositing a silver layer by a redox process. They have a mean diameter of 6 μm and their density has been matched to the density of water by adjusting the thickness of the metallic layer. In this work we used these particles as tracers to measure the velocity profile of an aqueous solution in a PDMS microchannel with a rectangular cross-section. This allowed us to confirm the predictions of the Stokes equation with results comparable to those of common polystyrene particles. © 2016 Elsevier B.V.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Fluorescent latex beads have been widely used as tracers in microfluidics for the last decades. They have the advantages to be density matched with water and to be easily localizable using fluorescence microscopy. We have recently synthesized silver-coated oil droplets that are both luminescent and absorptive, by first coating the oil interface with a polydopamine layer and then depositing a silver layer by a redox process. They have a mean diameter of 6 μm and their density has been matched to the density of water by adjusting the thickness of the metallic layer. In this work we used these particles as tracers to measure the velocity profile of an aqueous solution in a PDMS microchannel with a rectangular cross-section. This allowed us to confirm the predictions of the Stokes equation with results comparable to those of common polystyrene particles. © 2016 Elsevier B.V. |
Induction and differentiation of human induced pluripotent stem cells into functional cardiomyocytes on a compartmented monolayer of gelatin nanofibers Article de journal Y Tang; L Liu; J Li; L Yu; L Wang; J Shi; Y Chen Nanoscale, 8 (30), p. 14530–14540, 2016. @article{Tang:2016c, title = {Induction and differentiation of human induced pluripotent stem cells into functional cardiomyocytes on a compartmented monolayer of gelatin nanofibers}, author = {Y Tang and L Liu and J Li and L Yu and L Wang and J Shi and Y Chen}, url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-84980009741&doi=10.1039%2fc6nr04545f&partnerID=40&md5=0bfab8781ea6bb8d369db4f5b794ef39}, doi = {10.1039/c6nr04545f}, year = {2016}, date = {2016-01-01}, journal = {Nanoscale}, volume = {8}, number = {30}, pages = {14530--14540}, abstract = {Extensive efforts have been devoted to develop new substrates for culture and differentiation of human induced pluripotent stem cells (hiPSCs) toward cardiac cell-based assays. A more exciting prospect is the construction of cardiac tissue for robust drug screening and cardiac tissue repairing. Here, we developed a patch method by electrospinning and crosslinking of monolayer gelatin nanofibers on a honeycomb frame made of poly(ethylene glycol) diacrylate (PEGDA). The monolayer of the nanofibrous structure can support cells with minimal exogenous contact and a maximal efficiency of cell-medium exchange whereas a single hiPSC colony can be uniformly formed in each of the honeycomb compartments. By modulating the treatment time of the ROCK inhibitor Y-27632, the shape of the hiPSC colony could be controlled from a flat layer to a hemisphere. Afterwards, the induction and differentiation of hiPSCs were achieved on the same patch, leading to a uniform cardiac layer with homogeneous contraction. This cardiac layer could then be used for extracellular recording with a commercial multi-electrode array, showing representative field potential waveforms of matured cardiac tissues with appropriate drug responses. © 2016 The Royal Society of Chemistry.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Extensive efforts have been devoted to develop new substrates for culture and differentiation of human induced pluripotent stem cells (hiPSCs) toward cardiac cell-based assays. A more exciting prospect is the construction of cardiac tissue for robust drug screening and cardiac tissue repairing. Here, we developed a patch method by electrospinning and crosslinking of monolayer gelatin nanofibers on a honeycomb frame made of poly(ethylene glycol) diacrylate (PEGDA). The monolayer of the nanofibrous structure can support cells with minimal exogenous contact and a maximal efficiency of cell-medium exchange whereas a single hiPSC colony can be uniformly formed in each of the honeycomb compartments. By modulating the treatment time of the ROCK inhibitor Y-27632, the shape of the hiPSC colony could be controlled from a flat layer to a hemisphere. Afterwards, the induction and differentiation of hiPSCs were achieved on the same patch, leading to a uniform cardiac layer with homogeneous contraction. This cardiac layer could then be used for extracellular recording with a commercial multi-electrode array, showing representative field potential waveforms of matured cardiac tissues with appropriate drug responses. © 2016 The Royal Society of Chemistry. |
3D printed PEGDA microstructures for gelatin scaffold integration and neuron differentiation Article de journal X Tu; L Wang; J Wei; B Wang; Y Tang; J Shi; Z Zhang; Y Chen Microelectronic Engineering, 158 , p. 30–34, 2016. @article{Tu:2016, title = {3D printed PEGDA microstructures for gelatin scaffold integration and neuron differentiation}, author = {X Tu and L Wang and J Wei and B Wang and Y Tang and J Shi and Z Zhang and Y Chen}, url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-84960366751&doi=10.1016%2fj.mee.2016.03.007&partnerID=40&md5=42307f12059f0cb4516cb0ed542f3faa}, doi = {10.1016/j.mee.2016.03.007}, year = {2016}, date = {2016-01-01}, journal = {Microelectronic Engineering}, volume = {158}, pages = {30--34}, abstract = {Three dimensional (3D) printing techniques can be used for scaffold fabrication but the most of them are limited by resolution and material choice. To bypass these limitations, we developed an approach by combining conventional 3D printing and freeze-drying techniques to produce lattice-type backbone and embedding microporous structures. Polyethylene glycol diacrylate (PEGDA), a biocompatible and photosensitive pre-polymer, was chosen for 3D printing of the backbone, while gelatin was used for the formation of microporous structures. The fabricated PEGDA/gelatin scaffolds were used for culture and differentiation of neural progenitor cells (NPCs), showing infiltration of the cells and outgrowth of differentiated neurites. This strategy of combined use of 3D printing and freeze-drying techniques might be useful for scaffold fabrication in terms of easy design and easy material processing. © 2016 Elsevier B.V. All rights reserved.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Three dimensional (3D) printing techniques can be used for scaffold fabrication but the most of them are limited by resolution and material choice. To bypass these limitations, we developed an approach by combining conventional 3D printing and freeze-drying techniques to produce lattice-type backbone and embedding microporous structures. Polyethylene glycol diacrylate (PEGDA), a biocompatible and photosensitive pre-polymer, was chosen for 3D printing of the backbone, while gelatin was used for the formation of microporous structures. The fabricated PEGDA/gelatin scaffolds were used for culture and differentiation of neural progenitor cells (NPCs), showing infiltration of the cells and outgrowth of differentiated neurites. This strategy of combined use of 3D printing and freeze-drying techniques might be useful for scaffold fabrication in terms of easy design and easy material processing. © 2016 Elsevier B.V. All rights reserved. |
Fabrication of adjacent micropillar arrays with different heights for cell studies Article de journal J Wei; J Shi; B Wang; Y Tang; X Tu; E Roy; B Ladoux; Y Chen Microelectronic Engineering, 158 , p. 22–25, 2016. @article{Wei:2016, title = {Fabrication of adjacent micropillar arrays with different heights for cell studies}, author = {J Wei and J Shi and B Wang and Y Tang and X Tu and E Roy and B Ladoux and Y Chen}, url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-84960437498&doi=10.1016%2fj.mee.2016.03.008&partnerID=40&md5=1c3bf3dc7a83f6284d99208aca29220e}, doi = {10.1016/j.mee.2016.03.008}, year = {2016}, date = {2016-01-01}, journal = {Microelectronic Engineering}, volume = {158}, pages = {22--25}, abstract = {We fabricated adjacent micropillar arrays with different heights using different materials. Masters are obtained by using a two-step photolithography technique. A thin layer of SU8-3005 resist was spin coated on a chromium mask, followed by a front side exposure with another assistance mask, resulting in a step resist profile. Then, a thin layer of SU8-3010 resist was spin-coated again on the mask, followed by a back side exposure. The master patterns which consist of adjacent pillar arrays of different heights were replicated into polydimethylsiloxane (PDMS) by soft lithography. The PDMS replicas were then used as molds for casting or hot embossing, resulted in final pillars arrays in PDMS, poly lactic-co-glycolic acid (PLGA) and flexestene thermoplastic elastomer. Such substrates made of different materials were used to evaluate the surface stiffness dependent cell migration of NIH 3T3 cells. Our results show that the cells were sensitive to the height of PDMS pillars, due to their comparable Young's module, and that the cells were preferentially localized on the stiffer surfaces. However, no such effect was observed when the cells were placed on the PLGA substrate because of the excessive rigidity of the PLGA pillars. © 2016 Elsevier B.V. All rights reserved.}, keywords = {}, pubstate = {published}, tppubtype = {article} } We fabricated adjacent micropillar arrays with different heights using different materials. Masters are obtained by using a two-step photolithography technique. A thin layer of SU8-3005 resist was spin coated on a chromium mask, followed by a front side exposure with another assistance mask, resulting in a step resist profile. Then, a thin layer of SU8-3010 resist was spin-coated again on the mask, followed by a back side exposure. The master patterns which consist of adjacent pillar arrays of different heights were replicated into polydimethylsiloxane (PDMS) by soft lithography. The PDMS replicas were then used as molds for casting or hot embossing, resulted in final pillars arrays in PDMS, poly lactic-co-glycolic acid (PLGA) and flexestene thermoplastic elastomer. Such substrates made of different materials were used to evaluate the surface stiffness dependent cell migration of NIH 3T3 cells. Our results show that the cells were sensitive to the height of PDMS pillars, due to their comparable Young's module, and that the cells were preferentially localized on the stiffer surfaces. However, no such effect was observed when the cells were placed on the PLGA substrate because of the excessive rigidity of the PLGA pillars. © 2016 Elsevier B.V. All rights reserved. |
Agarose multi-wells for tumour spheroid formation and anti-cancer drug test Article de journal Y Tang; J Liu; Y Chen Microelectronic Engineering, 158 , p. 41–45, 2016. @article{Tang:2016a, title = {Agarose multi-wells for tumour spheroid formation and anti-cancer drug test}, author = {Y Tang and J Liu and Y Chen}, url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-84960467678&doi=10.1016%2fj.mee.2016.03.009&partnerID=40&md5=1cb4740d5a98f44d0b085535d8174ec8}, doi = {10.1016/j.mee.2016.03.009}, year = {2016}, date = {2016-01-01}, journal = {Microelectronic Engineering}, volume = {158}, pages = {41--45}, abstract = {Cell-based assays can be applied to evaluate the efficiency of anti-cancer drugs but the conventional approaches are mostly based on two-dimensional cell culture which is not able to recapitulate the tumour specificity. Here we developed a method to culture millimetre size tumour spheroids that is useful for anticancer drug studies. Agarose multi-wells were obtained by casting on polymethylsiloxane (PDMS) mould, which were then used for culture of U87-MG human glioblastoma. As expected, large size tumour spheroids could be generated after 24 h incubation. Comparing to the multi-well systems made of PDMS or polyethylene glycol diacrylate (PEGDA), agarose multi-wells are clearly advantageous due to the hydrophobic surface and the high permeability of agarose. After culture for 10 days, the tumour spheroids in agarose wells stopped to grow and the further increase of the cell seeding density had no effect on the final size of the spheroids. To study the anticancer drug effect, combretastatin A-4 (CA4) was added on day 2 or day 4, showing clear effects on the tumour spheroids and cell viability. More importantly, the live/dead cell staining images suggested that an earlier drug treatment was more efficient to prohibit the tumour spheroid growth. © 2016 Elsevier B.V. All rights reserved.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Cell-based assays can be applied to evaluate the efficiency of anti-cancer drugs but the conventional approaches are mostly based on two-dimensional cell culture which is not able to recapitulate the tumour specificity. Here we developed a method to culture millimetre size tumour spheroids that is useful for anticancer drug studies. Agarose multi-wells were obtained by casting on polymethylsiloxane (PDMS) mould, which were then used for culture of U87-MG human glioblastoma. As expected, large size tumour spheroids could be generated after 24 h incubation. Comparing to the multi-well systems made of PDMS or polyethylene glycol diacrylate (PEGDA), agarose multi-wells are clearly advantageous due to the hydrophobic surface and the high permeability of agarose. After culture for 10 days, the tumour spheroids in agarose wells stopped to grow and the further increase of the cell seeding density had no effect on the final size of the spheroids. To study the anticancer drug effect, combretastatin A-4 (CA4) was added on day 2 or day 4, showing clear effects on the tumour spheroids and cell viability. More importantly, the live/dead cell staining images suggested that an earlier drug treatment was more efficient to prohibit the tumour spheroid growth. © 2016 Elsevier B.V. All rights reserved. |
Effective motor neuron differentiation of hiPSCs on a patch made of crosslinked monolayer gelatin nanofibers Article de journal Y Tang; L Liu; J Li; L Yu; F P U Severino; L Wang; J Shi; X Tu; V Torre; Y Chen Journal of Materials Chemistry B, 4 (19), p. 3305–3312, 2016. @article{Tang:2016b, title = {Effective motor neuron differentiation of hiPSCs on a patch made of crosslinked monolayer gelatin nanofibers}, author = {Y Tang and L Liu and J Li and L Yu and F P U Severino and L Wang and J Shi and X Tu and V Torre and Y Chen}, url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-84969915347&doi=10.1039%2fc6tb00351f&partnerID=40&md5=825c1a9f3681efc28772e4b1c85afeee}, doi = {10.1039/c6tb00351f}, year = {2016}, date = {2016-01-01}, journal = {Journal of Materials Chemistry B}, volume = {4}, number = {19}, pages = {3305--3312}, abstract = {Human induced pluripotent stem cells (hiPSCs) are differentiated into mature motor neurons by using a culture patch made of crosslinked monolayer gelatin nanofibers. Compared to the conventional culture dish method, the patch method is more effective for culture and differentiation of stem cells, because cells are supported by a net-like structure made of crosslinked monolayer nanofibers instead of a planar substrate. The pores of the net-like structure have sizes smaller than those of cells but large enough to minimize the exogenous cell-material contact and to increase the permeability as well as the efficiency of cell-cell interactions. As expected, the differentiated hiPSCs showed the up-regulation of the expression of neuron specific proteins and the signature of matured motor neurons, allowing plug-and-play with a commercial multi-electrode array for neuron spike recording. © The Royal Society of Chemistry 2016.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Human induced pluripotent stem cells (hiPSCs) are differentiated into mature motor neurons by using a culture patch made of crosslinked monolayer gelatin nanofibers. Compared to the conventional culture dish method, the patch method is more effective for culture and differentiation of stem cells, because cells are supported by a net-like structure made of crosslinked monolayer nanofibers instead of a planar substrate. The pores of the net-like structure have sizes smaller than those of cells but large enough to minimize the exogenous cell-material contact and to increase the permeability as well as the efficiency of cell-cell interactions. As expected, the differentiated hiPSCs showed the up-regulation of the expression of neuron specific proteins and the signature of matured motor neurons, allowing plug-and-play with a commercial multi-electrode array for neuron spike recording. © The Royal Society of Chemistry 2016. |
Artificial honeycomb-inspired TiO2 nanorod arrays with tunable nano/micro interfaces for improving poly(dimethylsiloxane) surface hydrophobicity Article de journal R He; J Xiao; M Zhang; Z Zhang; W Zhang; Y Cao; Y Liu; Y Chen Journal of Materials Science, 51 (6), p. 2935–2941, 2016. @article{He:2016, title = {Artificial honeycomb-inspired TiO2 nanorod arrays with tunable nano/micro interfaces for improving poly(dimethylsiloxane) surface hydrophobicity}, author = {R He and J Xiao and M Zhang and Z Zhang and W Zhang and Y Cao and Y Liu and Y Chen}, url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-84953356119&doi=10.1007%2fs10853-015-9602-z&partnerID=40&md5=630860b1edb4f1a9d86fac91759d90ba}, doi = {10.1007/s10853-015-9602-z}, year = {2016}, date = {2016-01-01}, journal = {Journal of Materials Science}, volume = {51}, number = {6}, pages = {2935--2941}, abstract = {This work demonstrates a bottom-up model of fabricating a honeycomb-inspired interface consisting of micro- and nanostructures for improving poly(dimethylsiloxane) (PDMS) hydrophobicity. TiO2 nanorod arrays and microsized voids were fabricated by a two-step hydrothermal reaction method. First, rutile TiO2 nanorod arrays were hydrothermally fabricated on the fluorine-doped SnO2 conductive substrates substrate. Second, microsized TiO2 voids were synthesized through HCl hydrothermal etching to obtain a honeycomb-inspired interface with tunable size. The size of the etched voids increased from 0.22 ± 0.06 to 8.0 ± 2.8 μm. The interfaces were then transferred on the PDMS surface to improve hydrophobic property. The contact angles of the corresponding positive PDMS replicas reached 140° after etching with the TiO2 nanorod arrays for 10 h. The size of mastoid structures on the PDMS surfaces was 7.5 μm, which is similar to the size of microstructures on the lotus leaf surface. The fabricated PDMS surface with tunable hydrophobicity properties can be used in the microfluidic channels in the future. © 2015, Springer Science+Business Media New York.}, keywords = {}, pubstate = {published}, tppubtype = {article} } This work demonstrates a bottom-up model of fabricating a honeycomb-inspired interface consisting of micro- and nanostructures for improving poly(dimethylsiloxane) (PDMS) hydrophobicity. TiO2 nanorod arrays and microsized voids were fabricated by a two-step hydrothermal reaction method. First, rutile TiO2 nanorod arrays were hydrothermally fabricated on the fluorine-doped SnO2 conductive substrates substrate. Second, microsized TiO2 voids were synthesized through HCl hydrothermal etching to obtain a honeycomb-inspired interface with tunable size. The size of the etched voids increased from 0.22 ± 0.06 to 8.0 ± 2.8 μm. The interfaces were then transferred on the PDMS surface to improve hydrophobic property. The contact angles of the corresponding positive PDMS replicas reached 140° after etching with the TiO2 nanorod arrays for 10 h. The size of mastoid structures on the PDMS surfaces was 7.5 μm, which is similar to the size of microstructures on the lotus leaf surface. The fabricated PDMS surface with tunable hydrophobicity properties can be used in the microfluidic channels in the future. © 2015, Springer Science+Business Media New York. |
2015 |
One-step electroplating 3D template with gradient height to enhance micromixing in microfluidic chips Article de journal W He; J Xiao; Z Zhang; W Zhang; Y Cao; R He; Y Chen Microfluidics and Nanofluidics, 19 (4), p. 829–836, 2015. @article{He:2015, title = {One-step electroplating 3D template with gradient height to enhance micromixing in microfluidic chips}, author = {W He and J Xiao and Z Zhang and W Zhang and Y Cao and R He and Y Chen}, url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-84942982402&doi=10.1007%2fs10404-015-1607-z&partnerID=40&md5=8c49a05eae58ea4957e3dcdf4666e6f3}, doi = {10.1007/s10404-015-1607-z}, year = {2015}, date = {2015-01-01}, journal = {Microfluidics and Nanofluidics}, volume = {19}, number = {4}, pages = {829--836}, abstract = {A cost-effective method that used electroplating to fabricate a 3D polydimethylsiloxane (PDMS) passive micromixer was developed in this work. The mixer fabrication process characteristics were as follows: The chip design was transferred to indium tin oxide (ITO) glass via photolithography; the ITO glass was vertically immersed in a nickel electroplating solution; and the ITO glass was raised up by controlling by the syringe pump, while electroplating was in progress. In this method, the height of the mixing structure could increase gradient from 15 to 30 μm. Compared with a flat structure, this structure could increase mixing efficiency by at least 10 %. The mixing efficiency with this 3D microstructure can reach more than 80 %. This 3D microstructure fabrication method can be easily integrated with other PDMS functional structures for future point-of-care diagnostic applications because of the advantages of this technique. © 2015, Springer-Verlag Berlin Heidelberg.}, keywords = {}, pubstate = {published}, tppubtype = {article} } A cost-effective method that used electroplating to fabricate a 3D polydimethylsiloxane (PDMS) passive micromixer was developed in this work. The mixer fabrication process characteristics were as follows: The chip design was transferred to indium tin oxide (ITO) glass via photolithography; the ITO glass was vertically immersed in a nickel electroplating solution; and the ITO glass was raised up by controlling by the syringe pump, while electroplating was in progress. In this method, the height of the mixing structure could increase gradient from 15 to 30 μm. Compared with a flat structure, this structure could increase mixing efficiency by at least 10 %. The mixing efficiency with this 3D microstructure can reach more than 80 %. This 3D microstructure fabrication method can be easily integrated with other PDMS functional structures for future point-of-care diagnostic applications because of the advantages of this technique. © 2015, Springer-Verlag Berlin Heidelberg. |
Fabrication of cardiac patch by using electrospun collagen fibers Article de journal M Kitsara; P Joanne; S E Boitard; I Ben Dhiab; B Poinard; P Menasché; C Gagnieu; P Forest; O Agbulut; Y Chen Microelectronic Engineering, 144 , p. 46–50, 2015. @article{Kitsara:2015, title = {Fabrication of cardiac patch by using electrospun collagen fibers}, author = {M Kitsara and P Joanne and S E Boitard and I Ben Dhiab and B Poinard and P Menasch\'{e} and C Gagnieu and P Forest and O Agbulut and Y Chen}, url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-84924387992&doi=10.1016%2fj.mee.2015.02.034&partnerID=40&md5=8705b462c8708ed848d97ae3d82565a7}, doi = {10.1016/j.mee.2015.02.034}, year = {2015}, date = {2015-01-01}, journal = {Microelectronic Engineering}, volume = {144}, pages = {46--50}, abstract = {Synergy between micro-nanotechnology and regenerative medicine can lead to new tools for health improvement. In this study, we investigate the efficacy of electrospun scaffolds - fabricated using clinically approved collagen - as supports for cardiomyoblast culture. The scaffolds were prepared using non-toxic solvents and crosslinking agents and characterized by scanning electron microscopy and contact angle measurements. Among different types of collagen samples, we found that atelocollagen can produce better quality of electrospun fibers than acid and basic fibrous collagen. Our results also show that the cell culture performance can be improved by adjusting the crosslinking conditions. Typically, increasing the concentration of citric acid of the cross-link agents from 5% to 10% w/w and the post-crosslink baking time from 1.5 to 2.5 h led to significant increases of the cellular colonization of the scaffold, showing three-dimensional growth of cardiac cells due to the specific morphology of the fibrous scaffolds. Finally, in vivo tests of the biocompatibility of the fabricated scaffolds have been done using a mouse model of dilated cardiomyopathy. As expected, the biocompatibility of the scaffold was found excellent and no visible inflammation was observed after the implantation up to two weeks. However, 5% citric acid electrospun collagen scaffolds was less resistant in vivo, proving again the importance of the processing parameter optimization of the electrospun scaffolds. © 2015 Elsevier B.V.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Synergy between micro-nanotechnology and regenerative medicine can lead to new tools for health improvement. In this study, we investigate the efficacy of electrospun scaffolds - fabricated using clinically approved collagen - as supports for cardiomyoblast culture. The scaffolds were prepared using non-toxic solvents and crosslinking agents and characterized by scanning electron microscopy and contact angle measurements. Among different types of collagen samples, we found that atelocollagen can produce better quality of electrospun fibers than acid and basic fibrous collagen. Our results also show that the cell culture performance can be improved by adjusting the crosslinking conditions. Typically, increasing the concentration of citric acid of the cross-link agents from 5% to 10% w/w and the post-crosslink baking time from 1.5 to 2.5 h led to significant increases of the cellular colonization of the scaffold, showing three-dimensional growth of cardiac cells due to the specific morphology of the fibrous scaffolds. Finally, in vivo tests of the biocompatibility of the fabricated scaffolds have been done using a mouse model of dilated cardiomyopathy. As expected, the biocompatibility of the scaffold was found excellent and no visible inflammation was observed after the implantation up to two weeks. However, 5% citric acid electrospun collagen scaffolds was less resistant in vivo, proving again the importance of the processing parameter optimization of the electrospun scaffolds. © 2015 Elsevier B.V. |