Multifunctional polymer coatings for cell microarray applications

Biocompatible coatings with suitable chemistries for the immobilization of biomolecules are increasingly in demand, as they can be applied in a wide range of biomedical applications. In particular, multifunctional polymer coatings displaying reactive functional groups for the immobilization of specific biological factors that can influence the cellular response while at the same time exhibiting low nonspecific protein adsorption and cell attachment properties have the potential to significantly advance the fields of biomaterials and regenerative medicine. In this study, multifunctional polymer surface chemistries were developed for a cell microarray application with the aim of screening cellular interactions with surface immobilized factors. Coatings were prepared by the deposition of an allylamine plasma polymer pinning layer followed by the deposition of random copolymers of glycidyl methacrylate (GMA) and poly(ethylene glycol) methacrylate (PEGMA). Coatings were characterized by X-ray photoelectron spectroscopy (XPS), infrared spectroscopy, ellipsometry, and contact angle measurements. A variety of proteins as well as synthetic polymers were printed onto copolymer-coated slides using a high-precision contact microarrayer. Printing conditions were optimized for a fluorescently labeled model protein in regard to the temperature, humidity, pin geometry, concentration, and pH of the printing solution. Finally, the suitability of the surface chemistry for the evaluation of cellular responses to surface immobilized factors in a microarray format was demonstrated using HeLa cells.