Weak Hydrogen Bonds Lead to Self-Healable and Bioadhesive Hybrid Polymeric Hydrogels with Mineralization-Active Functions

Hydrogels with self-healing features that can spontaneously repair themselves upon mechanical damage are increasingly attractive for biomedical applications. Many attempts have been made to develop unique hydrogels possessing this property, as well as stimuli-responsiveness and biocompatibility; however, the hydrogel fabrication strategies often involve specific design of functional monomers that are able to optimally provide reversible physical or chemical interactions. Here, we report that weak hydrogen bonds, provided by oligo(ethylene glycol) methacrylate (OEGMA) and methacrylic acid (MAA), a monomer combination that is commonly used to prepare chemically cross-linking hydrogels, can generate self-healable hydrogels with mechanically resilient and adhesive properties through a facile one-step free radical copolymerization. The hydrogen bonds break and reform, providing an effective energy dissipation mechanism and synergic mechanical reinforcement. The physical properties can be simply tuned by OEGMA/MAA ratio control and reversible pH adjustment. Furthermore, the hydrogel can serve as a robust template for biomineralization to produce hydrogel composite that facilitate cell attachment and proliferations. This work is synthetically simple and dramatically increases the choice of amendable and adhesive hydrogels for industrial and biomedical applications.