MXene-based composites against antibiotic-resistant bacteria: current trends and future perspectives

Abstract

Today, finding novel nanomaterial-based strategies to combat bacterial resistance is an important field of science. MXene-based composites have shown excellent antimicrobial potential owing to their fascinating properties such as excellent photothermal effects, highly active sites, large interlayer spacing, unique chemical structures, and hydrophilicity; they have great potential to damage the bacterial cells by rupturing the bacterial cell membranes, enhancing the permeability across the membrane, causing DNA damages, reducing the metabolic activity, and generating oxidative stress. After inserting into or attaching on the surface of pathogenic bacteria, these two-dimensional structures can cause bacterial membrane disruption and cell content leakage owing to their sharp edges. Remarkably, MXenes and their composites with excellent photothermal performance have been studied in photothermal antibacterial therapy to combat antibiotic-resistant bacteria and suppress chronic wound infections, thus providing new opportunities for multidrug-resistant bacteria-infected wound healing. But, details about the possible interactions between MXene-based nanosystems and bacterial cell membranes are rather scarce. Also, the mechanisms of photothermal antibacterial therapy as well as synergistic tactics including photothermal, photodynamic or chemo-photothermal therapy still need to be uncovered. This review endeavors to delineate critical issues pertaining to the application of MXene-based composites against antibiotic-resistant bacteria, focusing on their photocatalytic inactivation, physical damage, and photothermal antibacterial therapy.

Fig. 1. The synergistic antibacterial mechanism for MXene/cobalt nanowires (CoNWs) with suitable photothermal property against pathogenic bacteria. SPEEK: sulfonated polyether ether ketone. Reproduced with permission from ref. Copyright 2020 Elsevier.

Fig. 2. MXene-based composites with bacterial killing effects, including biofilm resistant, intrinsic bactericidal, and thermo-ablation of bacteria strategies along with tissue regeneration features (in vivo). Reproduced with permission from ref. Copyright 2020 American Chemical Society.

Fig. 3. MXene (Ti₃C₂) thermo-sensitive hydrogels (TSG) containing ciprofloxacin (Cip) for combinational chemo-phototherapy therapy against multidrug-resistant bacteria, paving a way for sterilization and long-term inhibition of pathogenic bacteria. Reproduced with permission from ref. Copyright 2022 Elsevier.

Fig. 4. (A–C) Scanning electron microscopy (SEM) images of methicillin-resistant S. aureus biofilm eradicated by MXenes. Scale bar = 1 μm. Green arrows indicate the dimples on cell surface; red arrows indicate the dead cells with significant morphology alterations; red dot circles indicate the separated methicillin-resistant S. aureus cells or clusters containing a few cells after biofilm broken; “−” and “+” represent no NIR and with NIR, respectively. Reproduced with permission from ref. Copyright 2022 Elsevier.

Fig. 5. (A) The preparative process of composite aerogel from bacterial cellulose (BC), chitosan (CH), MXene, and silver nanowires (AgNWs). (B) The antibacterial mechanisms of the composite aerogel against pathogenic bacteria. Reproduced with permission from ref. Copyright 2022 Elsevier.

Fig. 6. MXene-hybridized silane films with antibacterial properties; MXene (Ti₃C₂) sheets were hybridized into the γ-glycidoxypropyltrimethoxysilane (γ-GPS) film on AA2024 aluminum (Al) alloy surface. Reproduced with permission from ref. Copyright 2020 Elsevier.

Fig. 7. The preparative process of multifunctional scaffolds (HPEM) for multidrug-resistant bacteria-infected wound healing purposes. MRSA: methicillin-resistant S. aureus; PDA: polydopamine; GTA: glycerol triacrylate; PGE: poly(glycerol-ethylenimine); PEI: polyethylenimine. Reproduced with permission from ref. Copyright 2021 American Chemical Society.