A 3D bioprinted gelatin/quaternized chitosan/decellularized extracellular matrix based hybrid bionic scaffold with multifunctionality for infected full-thickness skin wound healing

Skin wound repair, a highly integrated and overlapping process, is susceptible to infection, hyperoxia and excessive inflammation, which can delay wound healing or even lead to chronic wounds. In this study, a GQL/dGQue bilayered multifunctional scaffold, epidermis composed of gelatin (G), quaternized chitosan (Q) and lignin (L), and dermis composed of skin-derived decellularized extracellular matrix (d), gelatin and quercetin (Que), with bionic skin structure, was constructed by 3D bioprinting technology. The results showed that lignin effectively improved the mechanical properties (Young's modulus above 90 MPa) and regulated the appropriate degradation (about 84 % for 15 d) of the scaffold, as well as endowed it with good UV shielding properties. In addition, GQL/dGQue showed prominent antibacterial activity of 90.76 ± 4.94 % and 90.34 ± 4.14 % against E. coli and S. aureus, respectively, good free radical scavenging (87.22 ± 1.71 %) and significant anti-inflammatory properties. In vivo studies demonstrated that GQL/dGQue scaffold could effectively prevent wound infection and mitigate inflammation, thereby accelerating vascularization and regeneration of hair follicle and sebaceous gland with a remarkable wound closure of 98.29 ± 1.77 % at 21 d. Therefore, the GQL/dGQue bilayered multifunctional scaffold has a considerable potential to apply in skin tissue engineering for clinical wound repair.