Effect of surface roughness and nano-asperities on bacterial–substrate interactions of PHF-PDMS modified substrate through nanoarchitectonics

In the present study, we have investigated the role of surface roughness influencing bacterial adhesion as a key to inhibit catheter associated infections. Polydimethylsiloxane (PDMS) substrate was fabricated through the incorporation of polyhydroxy fullerenes (PHF) to induce nanoscale roughness. Surface characteristics of developed PHF-PDMS surfaces were carried out using bio-Atomic Force Microscopy (Bio-AFM), along with fluorescent staining–based adhesion analysis for Staphylococcus (cocci) and Klebsiella (rod-shaped) bacteria. PHF-PDMS exhibited significant nanoscale heterogeneity, reflecting through its altered roughness, and asymmetric height profiles influencing bacterial morphology. Bacteria grown on the PHF-PDMS substrate showed characteristic protruding and membrane morphological changes. Fluorescence imaging corroborated with other findings, showing reduction in bacterial growth, and spatially fragmented adhesion over PHF-PDMS compared to the control surface. Collectively, this study highlights that surface nanoarchitectonics offers antibiotic-free strategies for preventing biofilm formation on biomedical devices.