Fabrication Of Ordered Micro/nanostructured Substrates And Their Application On Cell Culturing

Cells-extracellular matrix (ECM)/substrates is of fundamental importance to study in the biometerials fields. The chemical or physical properties of the substrate surface can affect strongly on cell adhesion,embryonic development,proliferation,differentiation,wound healing, and even pathological processes. Generally, the adhesion of cells can be regulated by changing chemical property of the substrate surface. However, it may hard to provide 3D environment by chemical modificaition. In comparision,substrates with certain physical pattern or 3D substrates could not only regulate cell behavior or orientation, but also form a 3D environment in some aspect. Here,we present a simple method for fabricating ordered micro/nanostructured substrates with the desired features for cell culturing, the detail works are as follows:(1) We proposed the preparation of ordered micro/nanostructured substrates by using self-assembly method. The substrates with different degrees of pattern orientation were achieved by customizing the amount of stretching applied to polymer inverse opal films.Cells cultured on these substrates showed an adjustable morphology and alignment.Moreover, the inverse opal structure was infiltrated with different soft hydrogels. It was demonstrated that the adhesion ratio of cells, as well as the cell morphology and alignment,could be regulated by these hybrid substrates,(2) Inverse opal substrate with tunable nanoscale pattern was firstly fabricated based on the gradient stretching method. Moreover, cells on the gradient stretched inverse opal showed a corresponding alignment along with the elongation gradient of the substrate. This"random-to-aligned" cell gradient,which reproduces the insertion part of many connecting tissues, will have important applications in tissue engineering.(3) Hollow microfiber with micro-mesh structure was fabricated by two way exposure in combination with contact exposure. Moreover, with regard to different design, tube network system with single inlet, multiple branches and outlets can also be fabricated easily.In addition, hybrid fiber was fabricated by composed with hydrogel which encapsulated with drug. It was demonstrate that the drug could extrude and affect the cells adhered on the fiber surface. The proposed microfiber may have application in the perfused cell culture and drug release system.