Pt single-atom-functionalized 2D Al-TCPP MOF nanosheets for enhanced photodynamic antimicrobial therapy

Abstract

The pressing challenges posed by infectious diseases caused by pathogenic microbial infections have necessitated the development of advanced antimicrobial strategies. Among the promising avenues, photodynamic therapy (PDT) has emerged as a promising approach due to its non-invasive and targeted nature. Although it has been widely used in antibacterial therapy, there are still obstacles in precisely regulating the structure of photosensitizers to achieve satisfactory photodynamic performance. Herein, Pt single-atoms (SAs) are deposited on two-dimensional (2D) Al-TCPP metal-organic framework (MOF) nanosheets, creating Pt/Al-TCPP as the photosensitizer to boost reactive oxygen species (ROS) production for enhanced photodynamic antimicrobial therapy. By integrating Pt SAs onto 2D Al-TCPP MOF nanosheets, we not only improve the dispersion and stability of Pt atoms but also harness the synergistic effect between the MOF's crystal porous structure and Pt SAs, optimizing its light-trapping ability. This unique structure enhances the bridging unit between Pt SA and the porphyrin linker, facilitating efficient charge transfer and separation during illumination, ultimately boosting ROS production. In addition to the inherent photodynamic performance of Pt SAs, they can also increase the adsorption of oxygen, facilitate electron transfer, and improve charge separation, thus enhancing photodynamic ROS generation efficiency. Therefore, the Pt/Al-TCPP photosensitizer shows much greater efficacy in generating ROS under a 660 ​nm laser irradiation compared to Al-TCPP. Both in vitro and in vivo experiments demonstrate that the Pt/Al-TCPP nanosheets can effectively eliminate bacteria and promote wound healing in a short time at low doses under laser irradiation. This study underscores the advantages of integrating Pt SAs with Pt/Al-TCPP nanosheets and offers a highly effective photosensitizer for bacterial infections. The results pave the way for novel strategies in the antibacterial realm, highlighting the potential of Pt/Al-TCPP nanosheets as a promising therapeutic agent for efficient wound healing.