Platelet-rich plasma integrated stromal vascular fraction gel bioink for 3D bioprinting and skin wound repair

The shortage of skin grafts remains a key challenge in the repair of full-thickness skin defects, highlighting the urgent need for suitable 3D-bioprinted skin substitutes. Although various hydrogel bioinks have been developed for skin tissue engineering, few can simultaneously satisfy printability, appropriate mechanical properties, matched degradation, no immune rejection, and favorable biological activity. In this study, we developed and systematically optimized a PRP/SVF-gel composite bioink for skin bioprinting. Characterization results showed that the bioink presented obvious shear-thinning behavior and excellent printability, with adjustable swelling, degradation, and mechanical properties regulated by SVF-gel content. The optimized hydrogel possessed interconnected porous structure suitable for cell growth, high cytocompatibility, and matched degradation kinetics with skin wound healing. In vivo experiments demonstrated that the scaffold significantly accelerated wound closure and epithelialization, promoted angiogenesis, remodeled collagen distribution close to normal skin, and effectively inhibited scar formation, achieving high-quality skin regeneration. This multifunctional PRP/SVF-gel bioink achieves balanced mechanical and biological performance, showing great potential for clinical skin bioprinting and promising application value in traumatic wound repair, burn treatment.