LAUSR

The development of alternative strategies for the efficient treatment of subcutaneous abscesses that do not require the massive use of antibiotics and surgical intervention is urgently needed. Herein, a novel synergistic antibacterial strategy based on photodynamic (PDT) and NO gas therapy is reported, in which, a PDT-driven NO controllable generation system (Ce6@Arg-ADP) is developed with l-Arg-rich amphiphilic dendritic peptide (Arg-ADP) as a carrier. This carrier not only displays superior bacterial association and biofilm penetration performance, but also acts as a versatile NO donor. Following efficient penetration into the interior of the biofilms, Ce6@Arg-ADP can rapidly produce massive NO via utilizing the H2 O2 generated during PDT to oxidize Arg-ADP to NO and l-citrulline, without affecting singlet oxygen (1 O2 ) production. The combination of 1 O2 and the reactive by-products of NO offers notable synergistic antibacterial and biofilm eradication effects. Importantly, following efficient elimination of all bacteria from the abscess site, Arg-ADP can further generate trace quantities of NO to facilitate the angiogenesis and epithelialization of the wound tissues, thereby notably promotes wound healing. Together, this study clearly suggests that Arg-ADP is a versatile NO donor, and the combination of PDT and NO represents a promising strategy for the efficient treatment of subcutaneous abscesses.