Biomimetic gingival hydrogel promotes the integrated repair of peri-implant gingiva and bone by mobilizing multiple cells.

Abstract

During peri-implant bone augmentation surgery, insufficient gingival closure poses significant risks, including bacterial infection and loss of bone repair material, necessitating soft tissue augmentation techniques such as autologous gingival flap (AGF) grafting. However, the clinical application of AGF is limited by challenges like secondary trauma and flap inactivation. In this study, a three-dimensional printed tissue engineering biomimetic gingival flap (BGF) was designed to replace AGF by fully mimicking the composition, structure, and function of gingiva. The micropatterned gelatin methacryloyl (GelMA) modified with ε-polylysine can effectively reduce the risk of bacterial infection and reestablish the gingival barrier, while the porous GelMA can rebuild fiber networks. Promoting osteogenesis and membrane barrier functions are achieved by the dense zinc-rich GelMA. This study precisely constructed a three-layer BGF, whose surface featured a microscale honeycomb microstructure with an error of less than 1.5 %, and the middle layer was a controllable porous structure with adjustable pore sizes ranging from 10 to 70 μm. BGF exhibited broad-spectrum antibacterial activity with a bacteriostatic rate of approximately 90 %, function of promoting the regeneration of multiple tissues, and long-term membrane barrier function lasting at least 30 days. Furthermore, BGF accelerated soft tissue healing by 167.95 % and bone healing by 84.36 % in vivo through activating the paracrine effect of fibroblasts. BGF is expected to provide a more effective solution for implant patients with bone and soft tissue defects.