Enhanced Synergistic Antibacterial Activity through a Smart Platform Based on UiO-66 Combined with Photodynamic Therapy and Chemotherapy

Abstract

Harmful bacteria have seriously threatened human health and wealth for a long time. Herein, a multifunctional drug delivery system based on UiO-66 was fabricated, and it showed potent synergistic antibacterial effects when used in conjunction with photodynamic therapy and chemotherapy. First, UiO-66-NH₂ was prepared via a facile solvothermal method. Then, carboxylic zinc phthalocyanine, a broad-spectrum photosensitizer, was connected to UiO-66-NH₂ by amidation. Next, synergistic chemical antibiotic linezolid was loaded in the pores, and lysozyme was coated on the surface by electrostatic interactions. <i>In vitro</i> antibacterial experiments were then carried out to evaluate the antibacterial effects of this system against three kinds of bacteria, <i>Staphylococcus aureus</i>, <i>Escherichia coli</i>, and methicillin-resistant <i>S. aureus</i> (MRSA). The combination of lysozyme, linezolid, and singlet oxygen generated by irradiation of the photosensitizers resulted in a potent antibacterial effect against <i>S. aureus</i>, <i>E. coli</i>, and even MRSA, which demonstrates the synergistic antibacterial efficacy of photodynamic therapy and chemotherapy.