Fabricating Antipathogenic Interfaces via Nanoscale Topographies Inspired from Snake Skin

Abstract

Advancements in developing antipathogenic interfaces are critical in mitigating the risk of infection spread amid the practical limitations of hygienic control in crowded and resource-limited settings. Such requirements are also extremely compelling in busy patient care centers including intensive care units where the statutory maintenance of environmental standards often appears to be impractical because of the overflooded patient loads. While advances in surface engineering have emerged with great promises to cater these needs, the underlying technological complexities appear to be prohibitive against practicable applications amid constrained technological resources. Here, we harnessed the role of unique topographical features of the skin of Ptyas mucosa (oriental rat snake), a commonly found snake species in south and southeast Asia, in terms of exhibiting supreme antifouling properties via natural inheritance, leading to pathogenic resistance. Our characterization studies unveiled that unlike the previously reported vertical pillars, hairs, and needles, arrays of horizontal denticulation, offering favorable topographical characteristics of structured roughness and hierarchical features, emerged to be responsible for exhibiting the desired functionalities. We subsequently adapted these structures with certain simplifications by biomimicking artificially engineered topologies on a polydimethylsiloxane (PDMS) surface. The resulting surfaces were proven to offer dual antimicrobial mechanisms such as resistances to adhesion or colonization of different bacteria (Escherichia coli, Enterococcus faecalis, Klebsiella pneumoniae, Pseudomonas aeruginosa, Staphylococcus aureus, and Streptococcus mutans) and facilitation for cell wall deformation and programmed cell death as evidenced by an abundance of oxidative stresses. These results opened up strategies of producing biomimetic surface textures and their effective implementation against pathogenic invasion in a plethora of applications ranging from medical implants to marine propulsion.