Bioinspired bactericidal surfaces with polymer nanocone arrays

Abstract

Infections resulting from bacterial biofilm formation on the surface of medical devices are challenging to treat and can cause significant patient morbidity. Recently, it has become apparent that regulation of surface nanotopography can render surfaces bactericidal. In this study, poly(ethylene terephthalate) nanocone arrays are generated through a polystyrene nanosphere-mask colloidal lithographic process. It is shown that modification of the mask diameter leads to a direct modification of centre-to-centre spacing between nanocones. By altering the oxygen plasma etching time it is possible to modify the height, tip width and base diameter of the individual nanocone features. The bactericidal activity of the nanocone arrays was investigated against Escherichia coli and Klebsiella pneumoniae. It is shown that surfaces with the most densely populated nanocone arrays (center-to-center spacing of 200 nm), higher aspect ratios (>3) and tip widths <20 nm kill the highest percentage of bacteria (∼30%).

Antibacterial effects of nanopillar surfaces are mediated by cell impedance, penetration and induction of oxidative stress

“…Gram-negative envelopes consist of an outer and inner membrane, separated by a thin (≈5 nm) peptidoglycan cell wall that occupies the periplasmic space. By contrast, the Gram-positive bacterial cell wall is significantly thicker (≈20-100 nm) 13,17 , which may reduce stretching sensitivity. In addition to this, nanotopography geometries, including aspect ratio and nanopillar density, have been shown to influence the efficiency of bactericidal activity 3,5,13,18 .…”

“…The unique bactericidal properties of cicada and dragonfly wings have drawn significant research interest [7][8][9][10] , as the physical nature of bacterial killing could provide an effective strategy to prevent biofilm formation, and infection of indwelling and implantable devices, while negating the current need to use materials impregnated with antibiotics. To date, a wide range of nanofabrication techniques have been utilised to generate bactericidal nanotopographies on synthetic materials, including black silicon (bSi) 2 , titanium 11 , titanium alloy 12 and polymers 13 .…”

Multifunctional Coatings and Nanotopographies: Toward Cell Instructive and Antibacterial Implants

“…Hazzel et al produced similar nanopillar/cone surfaces using colloidal microbeads as masks followed by RIE. It was shown again that surfaces with the most densely packed nanopillar/cone arrays (center‐to‐center spacing of 200 nm), higher aspect ratios (<3), and sharp tip widths (>20 nm) killed the highest percentage of bacteria (≈30%) …”

“…Inspired by nature, a number of studies have since been carried out to develop bactericidal nanotopographies on synthetic materials. They include silicon and diamond coated silicon, titanium and its alloy, polymers, stainless steel, and aluminium . Table 3 lists a summary of biomimetic bactericidal surfaces on various materials currently in development.…”

Synthesis of photo-excited Chlorin e6 conjugated silica nanoparticles for enhanced anti-bacterial efficiency to overcome methicillin-resistant Staphylococcus aureus

“…[13][14][15][16][17][18][19][20][21] These nano-systems have attractive merits for the treatment of bacterial infection, namely their ease of surface functionalization, high antibacterial efficacy and ability to overcome bacterial resistance. [22][23][24][25] Among them, mesoporous silica nanoparticles are biodegradable, leading to excellent biocompatibility and biosafety, and the convenience of maintaining the release of bio-active molecules during their degradation. [26][27][28] All of these advantages make silica nanoparticles a desirable candidate for the delivery of antibiotics.…”