PEGDMA Hydrogels for Cell Adhesion and Optical Waveguiding.

Hydrogels are favored materials in tissue engineering as they can be used to imitate tissues, provide scaffolds, and guide cell behavior. Recent advances in the field of optogenetics have created a need for biocompatible optical waveguides, and hydrogels have been investigated to meet these requirements. However, combining favorable waveguiding characteristics, high biocompatibility, and controllable bioactivity in a single device remains challenging. Here, we investigate the use of poly(ethylene glycol) hydrogels as carriers and illumination systems for in vitro cell culture. We present a comprehensive and reproducible protocol for selective bioactivation of the hydrogels, achieving high proliferation rates and strong cell adhesion on the treated surface. A cell model expressing the photoconvertible fluorescent protein Dendra2 confirmed that light-cell interactions occur at the hydrogel surface. Monte Carlo simulations were performed as a tool to predict the extent of these interactions. This study demonstrates a hydrogel-based waveguiding system for targeted cell stimulation in vitro and potentially in vivo environments.