Understanding the (dis)-assembly of in situ forming hydrogel coatings in a 2D model system.

Hypothesis: Injectable hydrogels are important in situ forming implants for tissue regeneration at damaged sites. Understanding the behavior of these systems in a complex in vivo environment remains a challenge. Ultrathin films as 2D model systems are expected to provide fundamental insights into formation and (bio)degradation at material-liquid interfaces, and are also applicable as bioresponsive coatings.

Thiol-Thioester Exchange Reactions in Precursors Enable pH-Triggered Hydrogel Formation.

Bio-interactive hydrogel formation requires sensory capabilities toward physiologically relevant stimuli. Here, we report on pH-controlled hydrogel formation relying on latent cross-linkers, which transform from pH sensors to reactive molecules. In particular, thiopeptolide/thio-depsipeptides were capable of pH-sensitive thiol-thioester exchange reactions to yield α,ω-dithiols, which react with maleimide-functionalized multi-arm polyethylene glycol to polymer networks.