Molecular Dynamics Study on the Adsorption of Antimicrobial Peptides on the Surface of Al 2 O 3 Nanostructures in a Water Environment

Owing to their broad-spectrum antimicrobial activity and low tendency to induce resistance, antimicrobial peptides (AMPs) are highly regarded as candidates to construct antifouling coatings for marine equipment surfaces. Studies on AMPs have primarily focused on their adsorption characteristics on material surfaces. However, the adsorption behavior of AMPs on various nanostructured surfaces in an aqueous environment has not yet been revealed. Therefore, the adsorption process of AMP molecules was employed to investigate nanostructured Al2O3 surfaces, including rectangular grooves, triangular grooves, and semicircular grooves, in an aqueous environment by molecular dynamics simulations. First, the effects of different nanostructures on the adsorption of water molecules were investigated. In the rectangular grooves, the A03 system was observed to be more favorable for the attachment of water molecules on the substrate surface. In contrast, the width and depth of the grooves were found to have a comparatively minor influence on the adhesion of water molecules for the triangular grooves. Second, the influence of different nanostructures on the adsorption effectiveness of AMP molecules in aqueous solution was analyzed. The results indicated that the stability of AMPs' adsorption was not consistently enhanced by an increase in the width of the rectangular groove; however, it was weakened by an increase in the groove depth. In contrast, for the triangular grooves, the adsorption stability of AMPs was promoted with increasing groove width, whereas it was weakened by greater groove depth. Finally, the stability of AMPs' adsorption with the four structures was determined to follow the order ideal plane < semicircular groove < rectangular groove < triangular groove.