Injectable Gelatin-Farsi Gum Hydrogels Functionalized With Hydroxyapatite for Biomimetic Oral Bone Regeneration

Bone repair requires injectable biomaterials that solidify in situ, resist infection, and provide osteoconductive reinforcement. However, it remains unknown whether a photo-crosslinkable hydrogel can combine silver nanoparticle functionality with hydroxyapatite-driven mechanical support for mandibular regeneration.

An injectable hydrogel was synthesized from gelatin methacrylate and methacrylated Farsi gum, functionalized with silver nanoparticles and hydroxyapatite (0%, 5%, and 10% w/w). Chemistry and phase integration were verified by Fourier-transform infrared spectroscopy, x-ray diffraction, and proton nuclear magnetic resonance; swelling, degradation, porosity, and compression (including cyclic loading) were assessed at 5 and 12 weeks using radiography and histology; and rat mandibular healing was assessed at 5 and 12 weeks by radiography and histology.

Spectroscopic and diffraction analyses confirmed incorporation of all components. All formulations showed controlled swelling/degradation with porous architectures. Hydroxyapatite increased compressive performance, with 10% w/w yielding the highest strength and elastic recovery under repeated compression. In rat mandibles, the 10% hydroxyapatite hydrogel supported bone regeneration on radiographic and histologic assessment at Weeks 5 and 12.

These data show a single injectable platform that combines antimicrobial and anti-inflammatory functions with osteoconductive support, paving the way for minimally invasive craniofacial and orthopedic bone repair.