The rise of multidrug-resistant (MDR) bacteria highlights the urgent need for innovative antimicrobial strategies to prevent and control bacterial colonization and biofilm formation. Among these strategies, bactericidal nanostructured surfaces have emerged as promising candidates due to their capability to physically disrupt the bacterial envelope. In this study, the antibacterial efficacy of polymethyl methacrylate (PMMA) surfaces patterned via Electron Beam Lithography (EBL) with nanogratings and nanopillar arrays, arranged in Square (SQ) and Triangular (TR)-tiling geometries, all with a pitch of 210 nm, was investigated. The morphological and nanomechanical responses of Escherichia coli to these nanostructures were evaluated using Atomic Force Microscopy (AFM), Ultra High-Resolution Scanning Electron Microscopy (UHR-SEM), and Focused Ion Beam (FIB) milling. Results reveal that nanopatterned surfaces significantly reduce bacterial adhesion and induce pronounced alterations in cell morphology, including deformation, volume collapse, and membrane rupture. AFM-based force spectroscopy further indicates a decrease in Young’s modulus and an increase in adhesion forces between bacterial cells and the AFM tip, in bacteria exposed to nanopatterned substrates, supporting a mechano-bactericidal mechanism driven by membrane tension and mechanical stress. Importantly, biosafety assays using NIH/3T3 fibroblasts demonstrated preserved cell viability and enhanced spreading on nanopatterned PMMA, confirming cytocompatibility. Together, these findings provide direct experimental evidence of geometry-driven mechanical bacterial inactivation while maintaining mammalian cell compatibility, highlighting the potential of PMMA nanopatterned surfaces for antibacterial coatings in biomedical devices and healthcare environments. • Nanopatterned PMMA surfaces were fabricated by using EBL. • Nanopillar arrays reduced E. coli adhesion and drastically modified their shape. • AFM and SEM revealed bacterial deformation and membrane rupture. • Force spectroscopy showed increased adhesion and decreased cell stiffness. • Nanopatterned PMMA surfaces support NIH/3T3 fibroblast growth.
Pellegrino et al. (Fri,) studied this question.