Laser-Induced Photothermal Hydrogels Promote the Proliferation of MC3T3-E1 Preosteoblasts for Enhanced Bone Healing.

The nonunion and delayed union of bones are common challenges in orthopedic surgery, even when bone alignment is correct and sufficient mechanical stability is provided. To address this, artificial bone grafts are often applied to fracture gaps or defect sites to promote osteogenesis and enhance bone healing. In this study, we developed an alginate-based hydrogel incorporating gold nanoparticles (AuNPs) to enhance cell proliferation and facilitate bone healing through a photothermal effect induced by near-infrared (NIR) laser irradiation. The temperature was controlled by adjusting the AuNP content. The hydrogel's properties were characterized and cell viability was assessed. Our results indicate that while the incorporation of AuNPs slightly disrupted the hydrogel's cross-linking network at low concentrations, cell viability remained unaffected across both low and high AuNP contents. These findings suggest that this photothermal hydrogel holds great promise for orthopedic applications to improve bone healing.