# Bionic Nanocoating of Prosthetic Grafts Significantly Reduces Bacterial Growth

## TL;DR

A bionic nanocoating on prosthetic grafts reduces bacterial growth by 97%, using a superhydrophobic surface inspired by the Lotus effect.

## Contribution

A novel bionic nanocoating using silicon dioxide nanoparticles significantly reduces bacterial colonization on vascular prostheses.

## Key findings

- Coated prostheses showed a 97% reduction in bacterial colonization during artificial perfusion.
- The nanocoating achieved superhydrophobic properties with a water contact angle of >150°.
- SiO2 nanoparticles were non-toxic to various human cell types.

## Abstract

Prosthetic materials are a source of bacterial infections,
with
significant morbidity and mortality. Utilizing the bionic “Lotus
effect,” we generated superhydrophobic vascular prostheses
by nanocoating and investigated their resistance to bacterial colonization.
Nanoparticles were generated from silicon dioxide (SiO2), and coated vascular prostheses developed a nanoscale roughness
with superhydrophobic characteristics. Coated grafts and untreated
controls were incubated with different bacterial solutions including
heparinized blood under mechanical stress and during artificial perfusion
and were analyzed. Bioviability- and toxicity analyses of SiO2 nanoparticles were performed. Diameters of SiO2 nanoparticles ranged between 20 and 180 nm. Coated prostheses showed
a water contact angle of > 150° (mean 154 ± 3°)
and
a mean water roll-off angle of 9° ± 2°. Toxicity and
viability experiments demonstrated no toxic effects of SiO2 nanoparticles on human induced pluripotent stem cell-derived cardiomyocytes
endothelial cells, fibroblasts, and HEK239T cells. After artificial
perfusion with a bacterial solution (Luciferase+Escherichia coli), bioluminescence imaging measurements
showed a significant reduction of bacterial colonization of superhydrophobic
material-coated prostheses compared to that of untreated controls.
At the final measurement (t = 60 min), a 97% reduction
of bacterial colonization was observed with superhydrophobic material-coated
prostheses. Superhydrophobic vascular prostheses tremendously reduced
bacterial growth. During artificial perfusion, the protective superhydrophobic
effects of the vascular grafts could be confirmed using bioluminescence
imaging.