Synergistic Antimicrobial Titanium Carbide (MXene) Conjugated with Gold Nanoclusters

• Published in: Advanced healthcare materials 2020-10, Vol.9 (19), p.e2001007-n/a
• Main Authors: Zheng, Kaiyuan, Li, Shuo, Jing, Lin, Chen, Po‐Yen, Xie, Jianping
• Format: Article
• Language: English
• Subjects: Anti-Bacterial Agents - pharmacology; Anti-Infective Agents; Antibiotics; Antiinfectives and antibacterials; Antimicrobial agents; Bacteria; Bactericides; Biofilms; Chemical damage; Conjugation; Damage localization; DNA fragmentation; Gold; gold nanoclusters; Gram-Negative Bacteria; Gram-Positive Bacteria; Hydrophobicity; Lipids; Membranes; MXene nanosheets; MXenes; Nanoclusters; Nanomaterials; Nanotechnology; Oxidative stress; Reactive oxygen species; synergistic antimicrobial effects; Titanium; Titanium carbide
• ISSN: 2192-2640; 2192-2659
• DOI: 10.1002/adhm.202001007

Bacterial resistance toward antibiotics is a world‐wide problem, and one potential solution to fight against the resistance is to develop multi‐mechanism antimicrobial agents to achieve synergistic performance. Titanium carbide (MXene) is an emerging 2D nanomaterial with antimicrobial ability to physically damage bacterial membrane and chemically induce oxidative stress, and it can be further conjugated with nanomaterials to improve its antibacterial performance. Herein, a synergistic antimicrobial agent is developed through conjugation of the ultra‐small gold nanoclusters (AuNCs) on MXene nanosheets. The conjugated AuNCs are effectively delivered into bacteria after bacterial membrane damage caused by MXene, generating localized reactive oxygen species (ROS) of high concentration to effectively oxidize bacterial membrane lipid for enhanced membrane broken, as well as bacterial DNA for violent fragmentation. Thus, the synergistic physical (via MXene) and chemical (via MXene and AuNCs) antimicrobial mechanisms lead to eventual bacterial death of both Gram‐positive and Gram‐negative bacteria, with low IC50 values of 11.7 µg mL−1 of MXene and 0.04 µm of AuNCs. Moreover, the crumpled MXene‐AuNCs structure is constructed to inhibit biofilm formation, which hold synergistic antibacterial ability of MXene‐AuNCs conjugation, hydrophobic surface to prevent bacterial attachment, and large surface area containing higher density of bactericides. Synergistic antimicrobial agent is established through the conjugation of gold nanoclusters (AuNCs) onto the surface of MXene nanosheets. The synergistic antimicrobial ability is achieved physically (via MXene inseriting bacteria) and chemically (via MXene and AuNCs producing reactive oxygen species (ROS)) simultaneously.