A light‐controlled method for cell release by means of surface modification with photolabile linkers is presented. This approach is applicable to any material, provided that the linker is properly designed, and provides direct control over the molecular interactions involved in cell adhesion.

We report on the synthesis and properties of a photoactivatable caged RGD peptide and its application for phototriggering integrin and cell binding to surfaces. We analyzed in detail (i) the differences in the integrin binding affinity of the caged and uncaged forms via quartz crystal microbalance (QCM) studies, (ii) the efficiency and yield of the photolytic uncaging reaction, (iii) the biocompatibility of the photolysis byproducts and irradiation conditions and (iv) the possibility of site, temporal and density control of integrin binding and, therefore, human cell attachment, (v) the possibility of in situ generation of cell patterns and cell gradients by controlling the exposure. These studies provide a clear picture of the potential and limitations of caged ligands for integrin-mediated cell adhesion and demonstrate the application of this approach to control and study other types of cell interactions and response.

We present a phototriggerable system that allows for the spatiotemporal controlled attachment of selected cell types to a biomaterial using immobilized antibodies that specifically target individual cell phenotypes. o-Nitrobenzyl caged biotin was used to functionalize chitosan membranes and mediate site-specific coupling of streptavidin and biotinylated antibodies after light activation. The ability of this system to capture and immobilize specific cells on a surface was tested using endothelial-specific biotinylated antibodies and nonspecific ones as controls. Homogeneous patterned monolayers of human umbilical vein endothelial cells were obtained on CD31-functionalized surfaces. This is a simple and generic approach that is applicable to other ligands, materials, and cell types and shows the flexibility of caged ligands to trigger and control the interaction between cells and biomaterials.