Antibacterial effects of bio-inspired nanostructured materials

Several properties of bio-inspired surfaces like chemical composition, surface topography, surface hydrophilicity and even surface charge could influence bacterial adhesion to implant materials. Therefore, a nanostructured surface is being investigated to avoid bacterial colonization by their physico-mechanical and chemical aspects. Both smooth and rough-surfaced titanium (PT, SLA) and zirconia (M and ZLA) surfaces were used as controls. Titanium SLA was modified by two-step-etching to create nanostructured surface. Antibacterial properties of the materials were tested by adhesion of Porphyromonas gingivalis (ATCC 33277). The vitality of bacteria was assessed by Live/Dead BacLight™ Bacterial Viability Kit or by conventional culturing on Columbia blood agar. Conventional culturing revealed reduction of bacteria on nanostructured titanium (5.27±0.8 x 10(4) CFU/mm(2)) in comparison to rough-surfaced control materials (ZLA 6.16±4.86 x 10(4) and SLA 1.53±0.75 x 10(5) CFU/mm(2)). However, smooth-surfaced control materials (M 2.25±0.84 x 10(4) and PT 6.63±5.77 x 10(3) CFU/mm(2)) showed similar results to the nanostructured material. Live/dead staining demonstrated the antimicrobial efficacy of the nanostructured material revealing reduction of vital bacteria population up to 70%. This effect was not observed on the control materials (bacterial vitality ≥95%). In conclusion, nanostructured titanium surface shows a reduction of vital bacteria. Therefore, bio-inspired nanostructures can modify the bacteria–titanium interaction.