A triple-functional sandwich-like nanofibrous matrix for accelerated gingival augmentation

Keratinized gingival defect repair and soft tissue augmentation are crucial in oral and maxillofacial surgery, but current treatment strategies often face limitations such as insufficient antimicrobial properties, slow tissue regeneration, and poor control of the inflammatory microenvironment.

This study aims to design and validate a novel triple-functional "sandwich" structure nanofiber matrix to overcome the limitations of existing therapies. The research seeks to demonstrate that this matrix can mimic the mechanical properties of natural gingiva while possessing effective antibacterial capabilities, promoting angiogenesis and immunomodulation functions. Consequently, in vivo experiments confirmed its superiority over current standard therapies in regenerating soft tissue in the keratinized gingival area.

We fabricated a nanofiber matrix with a "sandwich" structure using electrostatic spinning technology. The inner layer is a polycaprolactone (PCL) membrane reinforced with antibacterial zinc oxide nanoparticles (ZnO NPs) to furnish mechanical stability. The outer layer is fabricated from PCL blended with recombinant human type I collagen (rhCol Ⅰ) and is additionally doped with ZnO NPs and Histatin-1 (Hst-1).

Experimental results indicate that this trifunctional nanofiber matrix exhibits a Young's modulus like natural gingiva, along with excellent antibacterial activity and the ability to promote collagen regeneration and angiogenesis. In a Beagle dog model,soft tissue volume gain in the keratinized gingival region increased by 153 ± 5 mm³ following implantation of this electrospun matrix. This outcome outperformed the commercial product Geistlich Mucograft® (63 ± 5 mm³) and autologous grafting (92 ± 6 mm³).

This study successfully developed a multifunctional nanofiber scaffold that combines excellent mechanical strength, antibacterial activity, and the promotion of collagen regeneration and angiogenesis. Experimental results confirm that this matrix effectively accelerates the regeneration of soft tissue in the keratinized gingival area, with efficacy significantly surpassing two existing standard therapies. This demonstrates that a comprehensive biomaterial strategy can simultaneously address multiple critical challenges-including antimicrobial activity, inflammation control, and tissue regeneration-offering a superior solution for repairing keratinized gingival defects.