Engineering Nanoclay Edges to Enhance Antimicrobial Property against Gram‐Negative Bacteria: Understanding the Membrane Destruction Mechanism by Contact‐Kill

Abstract

The overuse or abuse of antibiotics has led to serious health problems. During the recent decades, among the various methods used in antibacterial applications, some nanoclay minerals are proved antibacterial or inhibitory to the bacterial growth. However, the antibacterial mechanism of contact-kill based on the intrinsic structure of nanoclays is still unclear. Here, the antibacterial ability of pure clay is enhanced by creating more edge surfaces on kaolinite (Kaol) and the antibacterial mechanism is clarified at the atomic level. Based on experiments and density functional theory/molecular dynamics calculations, the positively charged Al(OH) and Al(OH 2 ) species on the edge surfaces of Kaol are confirmed to kill the Escherichia coli cells through direct contact by destroying their outer membrane (OM). The strong hydrogen bonding and van der Waals forces between OM and (110)/(11 10) surfaces of Kaol lead to the folding of OM. Simultaneously, the proton-coupled electron transfer between Lipopolysaccharide (LPS) and (11 10) edge surface of Kaol causes the dissociation of phosphoryl groups on LPS. Considering the similarities of most nanoclayson their edge surfaces, this finding may shed some light on the development of new nanoclay-based antibacterial materials in the future.

Tubular Nanoclay-Enhanced Calcium Phosphate Mineralization and Assembly to Impart High Stiffness and Antimicrobial Properties

“…45 Additionally, the strong hydrogen-bonding and van der Waals forces formed between hydroxyl groups on the mineral surface (clay minerals or HAP) and bacterial biofilms contribute to the disintegration of the bacterial biofilm. 46,47 Therefore, further studies were needed to investigate the interaction mechanism of CPH@P-5 with the bacterial surface.…”

Visible Light Locking in Mineral-Based Composite Phase Change Materials Enabling High Photothermal Conversion and Storage

“…The MD simulations were performed using the Forcite Module of Materials Studio software, and the force field was selected from universal . MD simulations were performed using the NVT ensemble, with the pressure fixed at 0.1 MPa and the temperature controlled at 310 K by the Nose-Berendsen method.…”

“…The MD simulations were performed using the Forcite Module of Materials Studio software, and the force field was selected from universal. 42 MD simulations were performed using the NVT ensemble, with the pressure fixed at 0.1 MPa and the temperature controlled at 310 K by the Nose-Berendsen method. The first 300 ps run was chosen to ensure that the system reached equilibrium, and the later 300 ps run was used to collect data for analyses.…”

Nanomaterials‐Enabled Physicochemical Antibacterial Therapeutics: Toward the Antibiotic‐Free Disinfections

“…Therefore, some cationic polymers, such as quaternary ammonium salt, can be grafted or anchored to the matrix surface to enhance the attraction of the surface to bacteria through charge action, [114,115] thus destroying the membrane of bacterial anionic lipids. [116] Such bioactive surfaces kill the bacteria directly in contact with them, named contact sterilization. Since the antibacterial chain segment is not released but produces bactericidal activity after interacting with the cell membrane, this strategy has a good self-bactericidal effect and longterm antibacterial activity.…”