Amylase degradation enhanced NIR photothermal therapy and fluorescence imaging of bacterial biofilm infections

Effective treatment of bacterial biofilm-related infections is a great challenge for the medical community. During the formation of biofilms, bacteria excrete extracellular polymeric substances (EPS), including polysaccharides, proteins, nucleic acids, etc., to encapsulate themselves and form a fort-like structure, which greatly reduces the efficiency of therapeutic agents. Herein, we prepared a nanoagent (MnO2-amylase-PEG-ICG nanosheets, MAPI NSs) with biofilm degradation capability for efficient photothermal therapy and fluorescence imaging of methicillin-resistant Staphylococcus aureus (MRSA) biofilm infections. MAPI NSs were constructed by sequentially modifying alpha-amylase, polyethylene glycol (PEG), and indocyanine green (ICG) on manganese dioxide nanosheets (MnO2 NSs). Experimental results exhibited that MAPI NSs could accumulate in infected tissues after intravenous injection, degrade in the acidic biofilm microenvironment, and release the loaded ICG for near-infrared (NIR) fluorescence imaging of the infected tissues. Importantly, MAPI NSs could efficiently eliminate MRSA biofilm infections in mice by alpha-amylase enhanced photothermal therapy. In addition, MAPI NSs exhibited neglectable toxicity towards mice. Given the superior properties of MAPI NSs, the enzyme-degradation enhanced therapeutic strategy presented in this work offers a promising solution for effectively combating biofilm infectious diseases.

Automated summary

This study developed a nanoagent with biofilm degradation capability for efficient treatment of bacterial biofilm infections. The nanoagent showed the ability to accumulate in infected tissues, degrade the biofilm, and efficiently eliminate the infection through photothermal therapy.