Electrostatic-Coordination Coupling Crosslinked Fullerenol-Ga Nanoparticles with Antioxidant, Osteogenic, and Antibacterial Bioactivities: A Promising Additive for Orthopedic Implant Modification.

The antibacterial property of fullerenes and their derivatives is highly dependent on light irradiation, which limits their biomedical applications. In this work, we report a novel type of nanoparticle composed of Fullerenol and gallium (Ga). The morphological features and chemical structures of the nanoparticles were characterized, and their assembly mechanism was further elucidated. Moreover, the antioxidant activity, osteogenic performance, and antibacterial effect of the Fullerenol-Ga under dark conditions were systematically investigated. The results show that the average diameter of individual Fullerenol-Ga nanoparticles is 10-30 nm. The assembly process between Fullerenol molecules and Ga3+ proceeds through a coupled mechanism of electrostatic adsorption and coordination crosslinking. The obtained Fullerenol-Ga exhibit remarkable scavenging ability against both DPPH and ABTS radicals, and effectively reduces the overall intracellular ROS level as well. Furthermore, high concentrations of nanoparticles can significantly promote the proliferation of MC3T3-E1 cells, enhance ALP activity, and upregulate the expression of early osteogenic related genes. Due to the unique "Trojan horse" antibacterial mechanism of Ga3+, the Fullerenol-Ga achieves an antibacterial rate of over 95% against both Escherichia coli and Staphylococcus aureus at a concentration of 150 μg/mL. Based on the multifaceted performance described above, this Fullerenol-Ga synergistic therapeutic system shows great potential as an additive for the surface modification of orthopedic implant materials.