Role of the Human Serum Albumin Protein Corona in the Antimicrobial and Photothermal Activity of Metallic Nanoparticles against Escherichia coli Bacteria

The emergence of antibiotic-resistant bacteria has becomea majorpublic health concern, leading to growing interest in alternativeantimicrobial agents. The antibacterial activity of metal nanoparticles(NPs) has been extensively studied, showing that they can effectivelyinhibit the growth of various bacteria, including both Gram-positiveand -negative strains. The presence of a protein corona, formed bythe adsorption of proteins onto the NP surface in biological fluids,can significantly affect their toxicity. Understanding the effectof the protein corona on the antimicrobial activity of metal NPs iscrucial for their effective use as antimicrobial agents. In this study,the antimicrobial activity of noble metal NPs, such as platinum (Pt),silver (Ag), and gold (Au) with and without the human serum albumin(HSA) protein corona against Escherichia coli strains, was investigated. In addition, the plasmonic photothermaleffect related to AuNPs, which resulted to be the most biocompatiblecompared to the other considered metals, was evaluated. The obtainedresults suggest that the HSA protein corona modulated the antimicrobialactivity exerted by the metal NPs against E. coli bacteria. These findings may pave the way for the investigationand development of innovative nanoapproaches to face antibiotic resistanceemergence.