Synthesis and characterization of a novel photothermal hydrogel composite with combined osteogenic and antibacterial activities.

Cranial defect repair remains a significant challenge in neurosurgery, and designing material complexes that can support bone regeneration while minimizing complications such as infection and inflammation could help alleviate this clinical challenge. This study presents a photothermal hydrogel complex with a controlled rapid gelation process, PDA-G-A-H, which integrates photothermal polydopamine nanoparticles (PDA NPs) with gentamycin (G) and alendronate acid (A). Furthermore, the incorporation of the injectable hydrogel Pluronic F127 and collagen (H) made this composite hydrogel (PDA-G-A-H) suitable for the multifaceted needs of cranial defects. The PDA-G-A-H hydrogel exhibited superior biocompatibility, as evidenced by high cell viability and minimal hemolysis, making it a safe candidate for biomedical applications. In vitro assessments with MC3T3-E1 cells demonstrated that this hydrogel enhanced mineralization and osteogenic differentiation, and significant upregulation of key osteogenic markers was subsequently detected. The antibacterial activity of the hydrogel against Staphylococcus aureus and Staphylococcus epidermidis was also investigated. The results of the RT‒PCR analysis revealed the potential for inhibiting biofilm formation. The hydrogel composite combines biocompatibility, osteoinductive, and antibacterial potential. It has translational potential for cranial defect repair and other bone regeneration therapies. Keywords: cranial defect, hydrogel, osteogenesis, antibacterial, biocompatibility, neurosurgery.