Novel multifunctional dual-dynamic-bonds crosslinked hydrogels for multi-strategy therapy of MRSA-infected wounds

Wound healing is a complex dynamic process involving hemostasis, inflammation, proliferation and remodeling stages. It is urgent need to develop multifunctional hydrogels to treat multiple links of wound healing. In this work, we designed novel multifunctional dual-dynamic-bonds crosslinked hydrogels through the electrostatic interaction between phenylboric acid and the amino group of chitosan, and the dynamic borate ester bond between phenylboric acid and the catechol structure of PDA-modified CNTs. This dual dynamic cross-linking mechanism endowed hydrogels with very fast self-healing properties, which could quickly form a whole dressing after being injected into the wound site. The phenylboric acid and catechol structures endowed hydrogels with excellent adhesion properties, the adhesion strength to pig skin was up to 27.6 kPa, could be used for hemostasis in vivo. Moreover, hydrogels displayed the advantages of injectable, rapid shape adaptation, antioxidant, biocompatibility, blood compatibility, electrical conductivity and photothermal antibacterial properties. In the MRSA-infected wound model, hydrogels could effectively reduce the expression level of wound inflammatory factors, accelerate collagen deposition, epithelial tissue and vascular regeneration, and thus promote wound healing. This work provides a new idea for the design of multi-strategy therapy for wound healing and has broad clinical application prospects.