PDA-BPs integrated mussel-inspired multifunctional hydrogel coating on PPENK implants for anti-tumor therapy, antibacterial infection and bone regeneration

Currently, many cancer patients with bone defects are still threatened by tumor recurrence, postoperative bacterial infection, and massive bone loss. Many methods have been studied to endow bone implants with biocompatibility, but it is difficult to find an implant material that can simultaneously solve the problems of anticancer, antibacterial and bone promotion. Here, a multifunctional gelatin methacrylate/dopamine methacrylate adhesive hydrogel coating containing 2D black phosphorus (BP) nanoparticle protected by polydopamine (pBP) is prepared by photocrosslinking to modify the surface of poly (aryl ether nitrile ketone) containing phthalazinone (PPENK) implant. The multifunctional hydrogel coating works in conjunction with pBP, which can deliver drug through photothermal mediation and kill bacteria through photodynamic therapy at the initial phase followed by promotion of osteointegration. In this design, photothermal effect of pBP control the release of doxorubicin hydrochloride loaded via electrostatic attraction. Meanwhile, pBP can generate reactive oxygen species (ROS) to eliminate bacterial infection under 808 nm laser. In the slow degradation process, pBP not only effectively consumes excess ROS and avoid apoptosis induced by ROS in normal cells, but also degrade into PO₄^3- to promote osteogenesis. In summary, nanocomposite hydrogel coatings provide a promising strategy for treatment of cancer patients with bone defects.