Virus-like mesoporous silica-coated plasmonic Ag nanocube with strong bacteria adhesion for diabetic wound ulcer healing

Abstract

The Gram-positive bacterium Staphylococcus aureus (MRSA) and the Gram-negative bacillus Escherichia coli (E. coli) can be commonly found in diabetic foot ulcers. However, the multi-drug resistant pathogenic bacteria infection is often difficult to eradicate by the conventional antibiotics and easy to spread which can lead to complications such as gangrene or sepsis. In this work, in order to pull through the low cell wall adhesion capability of typical antibacterial Ag nanoparticles, we fabricated biomimic virus-like mesoporous silica coated Ag nanocubes with gentamicin loading, and then the core-shell nanostructure was entrapped in the FDA approved hydrogel dressing. Interestingly, the Ag nanocubes with virus-like mesoporous silica coating are capable of effectively adsorbing on the rigid cell wall of both E. coli and MRSA. The intracellular H2S in natural bacterial environment can induce generation of small Ag nanospheres, which are the ideal antibacterial nanoagents. Combined with the gentamicin delivery, the pathogenic bacteria in diabetic wound can be completely eradicated by our dressing to improve the wound healing procedure. This virus-like core-shell nanostructure sheds light for the future wound healing dressing design to promote the clinical applications on antibacterial eradication.