An Injectable Self-Crosslinked Wholly Supramolecular Polyzwitterionic Hydrogel for Regulating Microenvironment to Boost Infected Diabetic Wound Healing

It is highly desirable yet significantly challenging to fabricate injectable, self-crosslinked, self-fused, and antifouling polyzwitterionic hydrogels, whose successful preparation will expand their application scope in biomedical fields. Herein, for the first time, a novel zwitterionic monomer, carboxybetaine urethane acrylate (CBUTA) is designed and synthesized with a urethane group and zwitterion on the same side chain. The strong inter-urethane H-bonds and zwitterionic dipole-dipole interactions of side chains contribute to self-crosslinked wholly supramolecular polyzwitterionic hydrogel that is directly formed from photoinitiated polymerization of CBUTA aqueous solution without adding any chemical crosslinkers. After being swollen in water, the polyCBUTA (PCBUTA) hydrogel is squeezed into small particles and freeze-dried to obtain hydrogel powder. The injectable and wholly zwitterionic supramolecular PCBUTA hydrogel can be easily reconstructed by mixing hydrogel powder with water due to the recombination of H-bonds of urethane groups and zwitterionic dipole-dipole interactions. The re-formed PCBUTA hydrogel exhibits an excellent self-fused and antifouling ability, and this injectable PCBUTA hydrogel, endowed with a microenvironment-regulated function, demonstrates excellent glucose consumption, antioxidation, antibacterial, and angiogenesis ability, thus accelerating the infected diabetic wound healing. Overall, this work provides a promising strategy to develop injectable and wholly zwitterionic hydrogels that will find broad biomedical applications.