Prussian blue-decorated indocyanine green-loaded mesoporous silica nanohybrid for synergistic photothermal-photodynamic-chemodynamic therapy against methicillin-resistant Staphylococcus aureus

Nanomaterial-based synergistic antibacterial agents are considered as promising tools to combat infections caused by antibiotic-resistant bacteria. Herein, multifunctional mesoporous silica nanoparticle (MSN)-based nanocomposites were fabricated for synergistic photothermal/photodynamic/chemodynamic therapy against methicillin-resistant Staphylococcus aureus (MRSA). MSN loaded with indocyanine green (ICG) as a core, while Prussian blue (PB) nanostructure was decorated on MSN surface via in situ growth method to form a core-shell nanohybrid (MSN-ICG@PB). Upon a near infrared (NIR) laser excitation, MSN-ICG@PB (200 μg mL −1 ) exhibited highly efficient singlet oxygen ( 1 O 2 ) generation and hyperthermia effect (48.7℃). In the presence of exogenous H 2 O 2 , PB with peroxidase-like activity promoted the generation of toxic hydroxyl radicals (•OH) to achieve chemodynamic therapy (CDT). PTT can greatly increase the permeability of bacterial lipid membrane , facilitating the generated 1 O 2 and •OH to kill bacteria more efficiently. Under NIR irradiation and exogenous H 2 O 2 , MSN-ICG@PB (200 μg mL −1 ) with good biocompatibility exhibited a synergistic antibacterial effect against MRSA with high bacterial killing efficiency (>98 %). Moreover, due to the synergistic bactericidal mechanism, MSN-ICG@PB with satisfactory biosafety makes it a promising antimicrobial agent to fight against MRSA.