An injectable collagen-silica tissue filler with collagen regeneration

Abstract

Tissue filling represents an effective strategy for correcting facial contour irregularities and eliminating facial wrinkles. In recent years, silica-based biomaterials have emerged as promising candidates for the development of novel tissue fillers, owing to their superior physical support and bioactivity. In this study, an injectable skin tissue filler (Col-SiO2) is developed by combining silica microspheres (SiO2, 20-45 μm) with biocompatible collagen hydrogel. The SiO2 microspheres in Col-SiO2 filler are capable of offering a spherical configuration for physical support and gradually releasing bioactive SiO32- ions, thereby simultaneously enabling wrinkle filling and inducing collagen regeneration. The Col-SiO2 filler shows appropriate mechanical injectability (injection force < 5 N) owing to its shear-thinning property, meeting the practical requirements for clinical application. Furthermore, the Col-SiO2 filler can effectively promote the proliferation, migration and collagen secretion of human skin fibroblasts cells (HSFs). Most importantly, the Col-SiO2 filler can induce collagen regeneration in vivo and maintain long-term filling stability, achieving superior subcutaneous filling and collagen deposition effects compared to hydroxyapatite (HAP)- and polymethyl methacrylate (PMMA)-based tissue fillers. Overall, the SiO2 microspheres offer a novel and effective strategy for developing skin tissue fillers aimed at wrinkle smoothing and collagen regeneration.