Effect of silica nano-spheres on adhesion of oral bacteria and human fibroblasts

Abstract

Objective: This study investigated the effect of surface nano-patterning on adhesion of an oral early commensal colonizer, Streptococcus mitis and the opportunistic pathogen Staphylococcus aureus and human fibroblasts (HDFa) in a laminar flow cell. Methods: Nanostructured surfaces were made by functionalizing glass substrates with 40 nm SiO 2 nanoparticles. Gradients in nanoparticle surface coverage were fabricated to study the effect of nanoparticle spacing within a single experiment. Bacterial adhesion was investigated after 5 min of contact time by subjecting surfaces to a flow in a laminar flow cell. In addition, to examine the particles effect on human cells, the establishment of focal adhesion and spreading of primary human dermal fibroblasts (HDFa) were investigated after 4 and 24 h. Results: Adhesion of both S. aureus and S. mitis decreased on surfaces functionalized with nanoparticles and coincided with higher nanoparticle surface coverage on the surface. Both strains were tested on three separate surfaces. The regression analysis showed that S. mitis was influenced more by surface modification than S. aureus. The establishment of focal adhesions in HDFa cells was delayed on the nanostructured part of the surfaces after both 4 and 24 h of culturing. Significance: In the current manuscript, we have used a flow cell to investigate the effect of nanotopographies on S. aureus and S. mitis adhesion. The present findings are of relevance for design of future implant and prostheses surfaces in order to reduce adhesion of bacteria.

Effect of a Nanostructured Titanium Surface on Gingival Cell Adhesion, Viability and Properties against P. gingivalis

“…Compared to the nanocavity surface in the present study, the nanostructures are almost double in length, thus appearing to be more effective in rupturing the murein wall. Another group reported that nanostructures functionalized by glass substrates with 40 nm SiO 2 nanoparticles decreased Streptococcus mitis and Staphylococcus aureus coverage of the sample [32]. While little is known about antimicrobial surfaces and their ideal structure for this purpose, the present study showed that it seems important to design a surface with irregularities in terms of irregular height levels, thereby increasing the mechanical stress on the bacteria murein wall.…”

Protein-coated nanostructured surfaces affect the adhesion of Escherichia coli

“…23 In addition, surface nanotopography can also affect bacterial adhesion. 24,25 When investigating surface nanotopography and its effect on biology, a common challenge is the need for a high throughput nanotopography manufacturing method with high reproducibility, high quality, and reasonable production time and costs. 26 One of the production techniques that could aid in this challenge is the combination of electron beam lithography (EBL) 27 and injection moulding.…”