Strategy for Preparing Mechanically Strong Hyaluronic Acid-Silica Nanohybrid Hydrogels via In Situ Sol-Gel Process

A hybridization method to prepare a hyaluronic acid (HA)-based nanohybrid hydrogel is proposed that introduces an additional inorganic silica network via an in situ sol-gel process. HA hydrogels have been extensively studied because of their excellent biocompatibility and biological functions; however, their poor mechanical strength hinders their use in tissue engineering applications. In the present work, the sol-gel technique is employed to achieve the formation of a structurally organized silica network in the HA hydrogel matrix rather than mixing of discrete particles with the HA polymer matrix. Importantly, the silica densification process results in significant enhancement of the mechanical properties. In addition, the nanohybrid hydrogels exhibit great degradation resistance and bioactivity on both fibroblast and pre-osteoblast cells. Moreover, the physical characteristics and biological properties can be modulated by varying the silica content; these materials thus show great potential for a wide range of applications for soft and hard tissues.