The Preparation And Application Of Photoinduced Reconfigurable Surface

Cell scaffolds play an essential role in in vitro cell incubation.Cell scaffolds can create a highly biomimetic environment for cell growth,imitating the properties of nature extracellular matrix,and providing guidance for cells to behave properly.Therefore,cell scaffolds need to be biodegradable,biocompatible and cell compatible.besides,it also needs to have certain characteristics of extracellular matrix,such as certain mechanical properties,adjustable chemical properties and so on.At present,there are some problems in the literature,such as single performance,static state,too fast or too slow degradation of materials.In this thesis,based on the photodynamic property of disulfide bonds,a porous HEMA-BMOD surface with adjustable physical and chemical properties was prepared for further patterning and cell behavior regulation.This surface can also be used for chips.The specific work is as followed:(1)Preparation of reconfigurable porous surface: Polyhydroxyethyl methacrylateBMOD(HEMA-BMOD)porous surface was prepared by radical polymerization initiated by ultraviolet light.The photochemical properties of the disulfide bond within the surface were used to further manipulate the HEMA-BMOD surface.The porous morphology was manipulated by exposing the HEMA-BMOD surface to 254 nm ultraviolet light.While under 365 nm UV,the porous surface could be chemically modified.The HEMA-BMOD surface was characterized with scanning electron microscope,ultraviolet absorption spectrum,X-ray photoelectron spectroscopy and Raman absorption spectrum.(2)Light-induced manipulation of the physiochemical properties of reconfigurable surface: 254 nm UV and 365 nm UV were used to manipulate the morphology and modify the surface respectively taking advantage of the photoreactivity of disulfide bonds inside the surface.The modification of Dibutyl Disulfide(DBD),Bis(2-Hydroxyethyl)disulfide(HED)and 2,2'-Dithiodipropionic Acid(DDA)onto the surface was successfully performed.Because of the reversible photoreactivity of disulfide bonds,the pre-modified surface could be erased and remodified with other functional groups.In addition,chemically morphologically patterned surfaces could be achieved by applying masks above the optical glass for light exposure.(3)Application of reconfigurable porous surfaces in cell culture: HEMA-BMOD porous surfaces with and without 254 nm UV exposure were used to cultivate fibroblasts and myoblasts,respectively.Fibroblasts were found to favor UV-treated surface,while myoblasts preferred rough surface without UV exposure.After 3 days cultivation on dots-patterned surface,fibroblasts gathered mostly on UV-treated area.Human bone marrow mesenchymal stem cells were cultured on surfaces with and without exposure.The cultured cells were subjected to flow cytometry and stained with alkaline phosphatase and alizarin S to observe osteogensis.In addition,HEMA-BMOD porous film can also be applied to a variety of chips to promote the development of organ chips.