Probiotic Vesicles-Implemented Multifunctional Nanotherapeutic Approach for Antibacterial, Anti-inflammatory, and Tissue Regeneration in Bacterial-Infected Oral Ulcer Healing.

Oral ulcer, characterized by mucosal damage, is susceptible to bacterial infection, tissue inflammation, and slow healing. Traditional treatments for oral ulcers only target on single function, such as antimicrobial, anti-inflammatory, or wound-healing, limiting the therapeutic efficacy. In this work, a multifunctional nanotherapeutic approach is developed, integrating antibacterial, anti-inflammatory, and tissue-healing properties for the treatment of oral ulcers with bacterial infection. Outer membrane vesicles (OMVs) derived from probiotic Escherichia coli Nissle 1917 serve as biocompatible carriers to load platinum nanoparticles (Pt NPs) and curcumin (Cur), acting as multifunctional Cur@OMV-Pt (COP) nanocomposite for the treatment of oral ulcer. The probiotic OMVs enhance the delivery and promote tissue regeneration owing to their rich components and functional biomolecules. Pt NPs with peroxidase-like and catalase-like activities catalyze H₂O₂ to generate reactive oxygen species and oxygen, exerting chemodynamic antibacterial therapy while enhancing photodynamic therapy of curcumin with anti-inflammatory effects. The COP nanocomposite effectively addresses the challenges of methicillin-resistant Staphylococcus aureus-infected oral ulcer by synergistically enhancing antibacterial, anti-inflammatory, and tissue-healing responses. This work presents a promising strategy for clinical applications in the treatment of oral ulcers and other bacterial infections, particularly in complex microenvironments.