Porphyrin MOF Dots-Based, Function -Adaptive Nanoplatform for Enhanced Penetration and Photodynamic Eradication of Bacterial Biofilms

Recently, antimicrobial photodynamic therapy (aPDT) has been considered as an attractive treatment option for biofilms ablation. However, even very efficient photosensitizers (PSs) still need high light doses and PS concentrations to eliminate biofilms due to the limited penetration and diffusion of PSs in biofilms. Moreover, the hypoxic microenvironment and rapid depletion of oxygen during PDT severely limit their therapeutic effects. Herein, for the first time, a porphyrin-based metal organic framework (pMOF) dots based nanoplatform with effective biofilm penetration, self-oxygen generation, and enhanced photodynamic efficiency is synthesized for bacterial biofilms eradication. The function-adaptive nanoplatform is composed of pMOF dots encapsulated by human serum albumin coated manganese dioxide (MnO2). The pH/H2O2-responsive decomposition of MnO2 in biofilms triggers the release of ultra small and positively charged pMOF dots and simultaneously generates O-2 in situ to alleviate hypoxia for biofilms. The released pMOF dots with high reactive oxygen species yield can effectively penetrate into biofilms, strongly bind with bacterial cell surface, and ablate bacterial biofilms. Importantly, such a nano platform can realize great therapeutic outcomes for treatment of Staphylococcus aureus infected subcutaneous abscesses in vivo without damage to healthy tissues, which offers a promising strategy for efficient biofilms eradication.