Monophasic hyaluronic acid-silica hybrid hydrogels for articular cartilage applications

Hyaluronic acid (HA), an FDA-approved natural polymer and important component of the extracellular matrix (ECM), has been widely used to develop hydrogels for cartilage regeneration. However, HA hydrogels often exhibit poor mechanical properties and unsuitable degradability, limiting their capability to support cell growth in cartilage. To overcome these challenges, this study modifies HA with a silica precursor and the coupling agent (3-Glycidyloxypropyl) trimethoxysilane (GPTMS) to develop a monophasic organic-inorganic hybrid HA-silica hydrogel. In this system, the inorganic silicate and organic HA components interpenetrate and bond covalently at the molecular level. The HA-silica hybrid hydrogel achieves a compressive modulus of 143 kPa at the highest GPTMS/HA molar ratio of 400. Additionally, in vitro cell studies show that these hybrid hydrogels have no cytotoxicity against MC3T3-E1 and ATDC-5 cells. Cell viability and morphology tests further confirm excellent cell adhesion on the hybrid scaffold. These results indicate that the developed HA-silica hybrid hydrogel is a suitable candidate for cartilage regeneration applications.