Near-infrared light-triggered drug delivery system based on aminated TiO2 nanotube arrays functionalized with black phosphorus composite hydrogel

Titanium-based implants are widely used due to their excellent mechanical properties and biocompatibility. However, post-implantation complications such as bacterial infections and insufficient bone integration remain challenges. This study focuses on the development of a near-infrared (NIR)--responsive drug delivery system based on TiO 2 nanotube arrays (TNTs) functionalized with black phosphorus composite hydrogels (BP@HCGG). The TNTs were fabricated via electrochemical anodization and aminated to enhance drug loading. Ibuprofen (IBU) was used as a model drug, and BP@HCGG was coated onto the TNTs to enable NIR-controlled release. The system demonstrated excellent photothermal properties, with rapid drug release under NIR light and minimal release in its absence. The phase transition temperature of BP@HCGG was optimized to ensure temperature-sensitive release at body temperature. Cell proliferation tests indicated good biocompatibility of the system. These results suggest that TNTs-NH 2 -IBU-BP@HCGG has significant potential for intelligent, NIR-controlled drug release, which can improve antimicrobial efficacy and promote bone integration in titanium-based implants.