Jelly-Inspired Injectable Guided Tissue Regeneration Strategy with Shape Auto-Matched and Dual-Light-Defined Antibacterial/Osteogenic Pattern Switch Properties.

Periodontitis is a bacterial infectious disease leading to the loss of periodontal supporting tissues and teeth. The current guided tissue regeneration (GTR) membranes for periodontitis treatments cannot effectively promote tissue regeneration for the limited antibacterial properties and the excessively fast degradation rate. Besides, they need extra tailoring according to variform defects before implantation, leading to imprecise match. This study proposed an injectable sodium alginate hydrogel composite (CTP-SA) doped with cubic cuprous oxide (Cu2O) and polydopamine-coated titanium dioxide (TiO2@PDA) nanoparticles for GTR. Inspired by the gelation process of the jelly, the phase change (liquid to solid) of CTP-SA after injection could automatch variform bone defects. Meanwhile, CTP-SA exhibited broad-spectrum antibacterial capabilities under blue light (BL) irradiation, including Streptococcus mutans (one of the most abundant bacteria in oral biofilms). Moreover, the reactive oxygen species released under BL excitation could accelerate the oxidation of Cu+ to Cu2+. Afterward, osteogenesis could be enhanced through two factors simultaneously: the stimulation of newly formed Cu2+ and the photothermal effect of CTP-SA under near-infrared (NIR) irradiation. Collectively, through this dual-light (blue and NIR) noninvasive regulation, CTP-SA could switch antibacterial and osteogenic modes to address requirements of patients at different healing stages, thereby realizing the customized GTR procedures.