The Development of Photosensitive Surfaces to Control Cell Adhesion and Form Cell Patterns

Abstract

Cell adhesion is the first step of cell response to materials and the extracellular matrix (ECM), and is essential to all cell behaviours such as cell proliferation, differentiation, migration and apoptosis for anchor-dependent cells. Therefore, studies of cell attachment have important implications to control and study cell behaviours. During many developed techniques for cell attachment, the manipulation of surface chemistry is a very important method to control initial cell attachment. To control cell adhesion on a two-dimensional surface is a simple model to study cell behaviours, and is a fundamental topic for cell biology, tissue engineering, and the development of biosensors. From the engineering point of view, the preparation of a material with controllable surface chemistry can help studies of cell behaviours and help scientists understand how surface features and chemistry influence cell behaviours. During the fabrication, the challenge is to create a surface with heterogeneous surface properties in the micro scale and subsequently to guide cell initial adhesion. In order to control cell adhesion in a spatial and temporal manner, a photochemical method to control surface chemistry was employed to control the surface property for cell adhesion in this project. Two photocleavable derivatives of the nitrobenzyl group were tried on two types of surfaces: a model self-assembled monolayer (SAM) with alkanethiol-gold surface and biodegradable chitosan. Reactive functional groups on two different surfaces can be inactivated by covalent binding with these photocleavable molecules, and light can be further introduced into the system as a stimulus to recover their reactivity. By simply applying a photomask with diffe