Highly biocompatible and recyclable biomimetic nanoparticles for antibiotic-resistant bacteria infection

Abstract

Increasing number of resistant bacteria have emerged with the overuse of antibiotics, which indicates that the bacterial infection has become a global challenge. Furthermore, the pollution of antibiotics to the environment has become a serious threat to public health. It is known that toxins produced by bacteria are the main cause of bacterial infections. Photothermal therapy is an effective antibacterial approach. However, the photothermal reagents cannot eliminate bacterial toxins, and even some anti-bacterial materials are toxic. Here, we synthesized a biomimetic recycled nanoparticle, red blood cell (RBC) membrane-coated Fe₃O₄ nanoparticles (RBC@Fe₃O₄), as an antibacterial agent. The RBC@Fe₃O₄ nanoparticles act as nano-sponges to trap toxins and then kill them all with a photothermal effect. We can describe this process simply as a battle between two armies. Our strategy is to disarm the “enemy” so that we can easily kill the “enemy” who has no power, which results in enhancing the bactericidal efficacy. The toxin of methicillin-resistant Staphylococcus aureus (MRSA) was absorbed by RBC@Fe₃O₄in vitro. In addition, in vivo studies proved that the RBC@Fe₃O₄ nanoparticles confer obvious survival benefits against toxin-induced lethality by absorbing the toxin of MRSA. Furthermore, using a mouse model of MRSA wound infection, the RBC@Fe₃O₄ nanoparticles with laser irradiation were found to have a superior wound-healing effect. Simultaneously, the RBC@Fe₃O₄ nanoparticles could be recycled in a simple way without affecting the bactericidal efficacy. The highly biocompatible and recyclable RBC@Fe₃O₄ biomimetic nanoparticles based on photothermal therapy and bacterial toxin adsorption strategy are promising for treating bacterial infections.