Break Up to Make Up: Utilization of Photocleavable Groups in Biolabeling of Hydrogel Scaffolds

Understanding cell behavior within the extracellular matrix is essential for the implementation of biomaterials in medical applications. Conjugation of bioactive molecules to hydrogel scaffolds imparts the materials with biological cues necessary for controlling cell behavior such as adhesion, growth and migration. Photo‐induced ligation is a powerful tool to precisely control when and where such bioactivity can be initiated. Over the past decade, advances in light‐regulated technology have emerged to address the stringent demands for photochemical ligation in biological environments, including high sensitivity, fast reaction kinetics, longer wavelength absorption and site‐selectivity. Here, the utilization of contemporary photolabile groups for light‐mediated bioconjugation of hydrogels are highlighted. In this approach, reactive groups such as thiol, amine and aldehyde are masked with photolabile moieties, which can be photo‐released to participate in click reactions, such as Michael addition and oxime ligation. New chromophores with long wavelength visible light absorption are also examined for potential employment in light‐induced bioconjugation.