An appropriate cell microenvironment is key to tissue engineering and regenerative medicine.Revealing the factors that influence the cell microenvironment is a fundamental research topic in the fields of cell biology,...An appropriate cell microenvironment is key to tissue engineering and regenerative medicine.Revealing the factors that influence the cell microenvironment is a fundamental research topic in the fields of cell biology,biomaterials,tissue engineering,and regenerative medicine.The cell microenvironment consists of not only its surrounding cells and soluble factors,but also its extracellular matrix(ECM)or nearby external biomaterials in tissue engineering and regeneration.This review focuses on six aspects of bioma-terial-related cell microenvironments:①chemical composition of materials,②material dimensions and architecture,③material-controlled cell geometry,④effects of material charges on cells,⑤matrix stiff-ness and biomechanical microenvironment,and⑥surface modification of materials.The present chal-lenges in tissue engineering are also mentioned,and eight perspectives are predicted.展开更多
Since the pioneering work of Messersmith’s group discovering that polydopamine(PDA)can serve to adhere to many types of materials,the PDA coating has,as a biomimetic approach,been widely used to enhance cell adhesion...Since the pioneering work of Messersmith’s group discovering that polydopamine(PDA)can serve to adhere to many types of materials,the PDA coating has,as a biomimetic approach,been widely used to enhance cell adhesion by surface modification to bind biologically active substances to a bioinert substrate.Nevertheless,it is unclear whether or not the PDA itself is beneficial for cells.Herein,we report that a PDA coating decreases viability of cells under normal culture and observation conditions.Such an inhibition effect was not caused by the free PDA or any inherent cytotoxicity of this chemical substance but a contactdependent phenomenon.Human bone marrow mesenchymal stem cells were employed as the default cell type and tissue culture plates were used as the default substrate,although some other cell types and substrates were also examined to confirm the universality of such an‘abnormal’phenomenon of a superstar molecule.The viability of cells on the PDA coating exhibited time dependence,and the decreased cell viability during the normal observation time was found to come from the decrease of cell number instead of the decrease of average viability per cell.The PDA coating led to less cell global migration yet more local motility of cells.Based on the concept of‘background adhesion’of cells on a surface without significant motifs of specific cell adhesion,we supposed that cells adhered to the PDA coating better,which influenced mobility and eventually proliferation.Hence,the cell behaviors on the PDA coating are reasonable,albeit a bit complicated.展开更多
While most studies of mechanical stimulation of cells are focused on two-dimensional(2D)and three-dimensional(3D)systems,it is rare to study the effects of cyclic stretching on cells under a quasi-3D microenvironment ...While most studies of mechanical stimulation of cells are focused on two-dimensional(2D)and three-dimensional(3D)systems,it is rare to study the effects of cyclic stretching on cells under a quasi-3D microenvironment as a linkage between 2D and 3D.Herein,we report a new method to prepare an elastic membrane with topographic microstructures and integrate the membrane into a microfluidic chip.The fabrication difficulty lay not only in the preparation of microstructures but also in the alignment and bonding of the patterned membrane to other layers.To resolve the problem,we designed and assembled a fast aligner that is cost-effective and convenient to operate.To enable quasi-3D microenvironment of cells,we fabricated polydimethylsiloxane(PDMS)microwell arrays(formed by micropillars of a few microns in diameter)with the microwell diameters close to the cell sizes.An appropriate plasma treatment was found to afford a coating-free approach to enable cell adhesion on PDMS.We examined three types of cells in 2D,quasi-3D,and 3D microenvironments;the cell adhesion results showed that quasi-3D cells behaved between 2D and 3D cells.We also constructed transgenic human mesenchymal stem cells(hMSCs);under cyclic stretching,the visualizable live hMSCs in microwells were found to orientate differently from in a 3D Matrigel matrix and migrate differently from on a 2D flat plate.This study not only provides valuable tools for microfabrication of a microfluidic device for cell studies,but also inspires further studies of the topological effects of biomaterials on cells.展开更多
基金the financial support from the National Natural Science Foundation of China (21961160721 and 52130302)the National Key Research and Development Program of China(2016YFC1100300)
文摘An appropriate cell microenvironment is key to tissue engineering and regenerative medicine.Revealing the factors that influence the cell microenvironment is a fundamental research topic in the fields of cell biology,biomaterials,tissue engineering,and regenerative medicine.The cell microenvironment consists of not only its surrounding cells and soluble factors,but also its extracellular matrix(ECM)or nearby external biomaterials in tissue engineering and regeneration.This review focuses on six aspects of bioma-terial-related cell microenvironments:①chemical composition of materials,②material dimensions and architecture,③material-controlled cell geometry,④effects of material charges on cells,⑤matrix stiff-ness and biomechanical microenvironment,and⑥surface modification of materials.The present chal-lenges in tissue engineering are also mentioned,and eight perspectives are predicted.
基金financially supported by the National Natural Science Foundation of China(grants No.52130302,21961160721).
文摘Since the pioneering work of Messersmith’s group discovering that polydopamine(PDA)can serve to adhere to many types of materials,the PDA coating has,as a biomimetic approach,been widely used to enhance cell adhesion by surface modification to bind biologically active substances to a bioinert substrate.Nevertheless,it is unclear whether or not the PDA itself is beneficial for cells.Herein,we report that a PDA coating decreases viability of cells under normal culture and observation conditions.Such an inhibition effect was not caused by the free PDA or any inherent cytotoxicity of this chemical substance but a contactdependent phenomenon.Human bone marrow mesenchymal stem cells were employed as the default cell type and tissue culture plates were used as the default substrate,although some other cell types and substrates were also examined to confirm the universality of such an‘abnormal’phenomenon of a superstar molecule.The viability of cells on the PDA coating exhibited time dependence,and the decreased cell viability during the normal observation time was found to come from the decrease of cell number instead of the decrease of average viability per cell.The PDA coating led to less cell global migration yet more local motility of cells.Based on the concept of‘background adhesion’of cells on a surface without significant motifs of specific cell adhesion,we supposed that cells adhered to the PDA coating better,which influenced mobility and eventually proliferation.Hence,the cell behaviors on the PDA coating are reasonable,albeit a bit complicated.
基金supported by the National Natural Science Foundation of China(grants no.51803032,21961160721,52130302,22175041).
文摘While most studies of mechanical stimulation of cells are focused on two-dimensional(2D)and three-dimensional(3D)systems,it is rare to study the effects of cyclic stretching on cells under a quasi-3D microenvironment as a linkage between 2D and 3D.Herein,we report a new method to prepare an elastic membrane with topographic microstructures and integrate the membrane into a microfluidic chip.The fabrication difficulty lay not only in the preparation of microstructures but also in the alignment and bonding of the patterned membrane to other layers.To resolve the problem,we designed and assembled a fast aligner that is cost-effective and convenient to operate.To enable quasi-3D microenvironment of cells,we fabricated polydimethylsiloxane(PDMS)microwell arrays(formed by micropillars of a few microns in diameter)with the microwell diameters close to the cell sizes.An appropriate plasma treatment was found to afford a coating-free approach to enable cell adhesion on PDMS.We examined three types of cells in 2D,quasi-3D,and 3D microenvironments;the cell adhesion results showed that quasi-3D cells behaved between 2D and 3D cells.We also constructed transgenic human mesenchymal stem cells(hMSCs);under cyclic stretching,the visualizable live hMSCs in microwells were found to orientate differently from in a 3D Matrigel matrix and migrate differently from on a 2D flat plate.This study not only provides valuable tools for microfabrication of a microfluidic device for cell studies,but also inspires further studies of the topological effects of biomaterials on cells.
