Strong Near-Infrared Absorbing and Biocompatible CuS Nanoparticles for Rapid and Efficient Photothermal Ablation of Gram-Positive and -Negative Bacteria

Abstract

Staphylococcus aureus (S. aureus) and Escherichia coli (E. coli) are the most common infectious bacteria in our daily life, and seriously affect human's health. Because of the frequent and extensive use of antibiotics, the microbial strains forming drug resistance have become more and more difficult to deal with. Herein, we utilized bovine serum albumin (BSA) as the template to synthesize uniform copper sulfide (CuS) nanoparticles via a biomineralization method. The as-prepared BSA-CuS nanocomposites showed good biocompatibility and strong near-infrared absorbance performance and can be used as an efficient photothermal conversion agent for pathogenic bacteria ablation with a 980 nm laser at a low power density of 1.59 W/cm. The cytotoxicity of BSA-CuS nanocomposite was investigated using skin fibroblast cells and displayed good biocompatibility. Furthermore, the antibacterial tests indicated that BSA-CuS nanocomposite showed no antibacterial activity without NIR irradiation. In contrast, they demonstrated satisfying killing bacterial ability in the presence of NIR irradiation. Interestingly, S. aureus and E. coli showed various antibacterial mechanisms, possibly because of the different architectures of bacterial walls. Considering the low cost, easy preparation, excellent biocompatibility and strong photothermal convention efficiency (24.68%), the BSA-CuS nanocomposites combined with NIR irradiation will shed bright light on the treatment of antibiotic-resistant pathogenic bacteria.

Dendritic Fe3O4@Poly(dopamine)@PAMAM Nanocomposite as Controllable NO‐Releasing Material: A Synergistic Photothermal and NO Antibacterial Study

“…In addition to NO, nanomaterial‐based photothermal therapy is recognized as a promising way for combating bacterial infections . The photoconversion nanomaterials are able to absorb light, especially the near‐infrared light and release it as heat, causing the elevation of the local temperature.…”

Antimicrobial Metal Nanomaterials: From Passive to Stimuli‐Activated Applications

“…[ 71,220,221 ] This absorbed energy can be dissipated either by re‐emitting a photon, or via heat through electron–electron interactions and then electron–phonon relaxation, which induces vibrations in the metal lattice structures, these lattice vibrations are transferred into thermal energy causing localized heat around the nanomaterial [ 44,71,220 ] ( Figure ). This phenomenon has been predominately studied using gold; however silver, [ 222 ] copper, [ 223 ] and other materials [ 224 ] have also been investigated. By conjugating specific attachments to the nanomaterials, such as antibodies, they can specifically target the pathogen of interest, where the localized increase in temperature causes cell death through a suite of actions including denaturation of essential proteins/enzymes, induction of heat shock proteins, disruption of metabolic signaling and rupture of the cell membrane [ 71,85,218,219,225–227 ] (Figure 10).…”

“…Reproduced with permission. [ 223 ] Copyright 2017, ACS Publications. F) Anti‐salmonella‐antibody‐conjugated oval‐shaped gold nanoparticles.…”

“…Reproduced with permission. [ 223 ] Copyright 2017, ACS Publications. M) Inactivation effects of Fe 5 C 2 nanoparticles (50 mg L −1 , pH 6) and NIR irradiation for E. coli (top) and S. aureus (bottom).…”

The Use of Nanomedicine for Targeted Therapy against Bacterial Infections

“…Copper sulfide a cheaper alternative when conjugated with bovine serum albumin showed no killing activity in antibacterial tests for Staphylococcus aureus and Escherichia coli. However, after NIR exposure, the nanocomposite at low concentration exhibited strong NIR irradiation absorbance and can be used as an efficient photothermal conversion agent for bacteria ablation (80%) with a 980 nm laser within 10 min [56]. Tong et al (2018) reported that the nanocomposite of DNA with Ag-nanoparticles and Graphene (ssDNA-AgNPs@GO) presented larger activity against Gram-positive and Gram-negative bacteria with low MIC compared to ssDNA-Ag-nanoparticles and GO alone [57].…”