Macroporous and Antibacterial Hydrogels Enabled by Incorporation of Mg-Cu Alloy Particles for Accelerating Skin Wound Healing

Repair of severe skin tissue injury remains a great challenge and wound infection is still a formidable problem. In this study, new macroporous and antibacterial gelatin/alginate (SAG)-based hydrogels for wound repair were designed and developed based on in-situ gas foaming method and ion release strategy as a result of Mg-Cu particles degradation in the hydrogel matrix. The addition of Mg-Cu particles decreased the storage modulus of SAG, maintained its mechanical resilience and enhanced its water-absorbing capability. Moreover, the water vapor transmission rate of SAG added with 2 wt.% Mg-Cu (SAG-2MC) was 124% of that of medical gauze and 804% of commercial Tegaderm™ film dressing. The bacterial inhibition rates of SAG-2MC against S. aureus, E. coli and P. aeruginosa reached 99.9% ± 0.1%, 98.7% ± 1.2% and 98.0% ± 0.7%, respectively, significantly greater than those of the SAG hydrogel and Mg particle-modified hydrogels. In addition, SAG-2MC hydrogel was biocompatible and promoted cell migration. In vivo experiment results indicated that SAG-2MC significantly accelerated the skin wound healing in murine model as demonstrated by higher epidermis thickness, more collagen deposition and enhanced angiogenesis compared with SAG-0MC, SAG-2M and Tegaderm™ film. In summary, Mg-Cu particles have great potential to modulate the physiochemical and biological properties of SAG hydrogels. Mg-Cu particle-modified SAG hydrogels reveal significant promise in the treatment of severe skin wound or other soft tissue lesions.