The photothermal-piezoelectric dual-responsive antibacterial prosthesis interface regulates Schwann cell phenotypic conversion to promote the repair of infectious bone defects.
Infected bone defects present a major clinical challenge. Persistent bacterial infection and the inflammatory microenvironment not only directly impede bone healing but also lead to peripheral nerve impairment, which further compromises the regeneration process. While conventional implants offer mechanical support, they lack the multifunctional capacity to simultaneously eradicate infection and orchestrate neuro-coupled bone healing often resulting in implant failure. In this study, black phosphorus quantum dots (BPQDs) were used to endow graphene-like carbon nitride (g-C3N4, CN) with photothermal activity and enhanced piezoelectric properties. Additionally, BP/CN hydrogel was prepared to modify 3D-printed titanium prostheses for the treatment of infectious bone defects. The prosthesis interface constructed achieved a strong antibacterial effect through the synergy of photothermal and sonodynamic therapies. It also promoted Schwann cell transformation towards a repair type and the secretion of neurotrophic factors, thereby promoting peripheral nerve repair and nerve-guided bone regeneration in the defect area. The results showed that the calcium ion-mediated MAPK/JNK signaling pathway plays a key role in the regulation of Schwann cell phenotypic conversion. Thus, this advanced implant design provides an integrated strategy that concurrently addresses infection control, nerve repair, and osteogenesis, offering a promising therapeutic platform for complex bone defect reconstruction.