Anti-bacterial properties of collagen-coated glass and polydimethylsiloxane substrates

Attachments of three bacterial species, Escherichia coli, Staphylococcus aureus, and Pseudomonas aeruginosa on chemically modified glass slides and polydimethylsiloxane substrates were investigated with an attempt to find anti-bacterial materials which can prevent bacterial infections. The results showed that the attachment of the first two species was largely reduced on surfaces treated with self-assembled monolayers plus collagen type 1, whereas attachment of Pseudomonas aeruginosa was not affected on all the treated/untreated surfaces. Gentamicin protection assay showed that the fewest Pseudomonas aeruginosa were engulfed by macrophages when the substrates were coated with (3-aminopropyl)triethoxysilane/(3-aminopropyl)trimethoxysilane plus glutaraldehyde plus collagen type 1. Considering that both Pseudomonas aeruginosa and macrophage adhesion were not influenced very much by the chemical modifications, the decreased engulfment of Pseudomonas aeruginosa was attributed to its decreased ability to invade macrophage cells on the two coated substrates. The results indicate that by employing appropriate chemical modifications, bacterial adhesion could be weakened with a decreased bacterial engulfment response of macrophages to the coated substrates, which shows an interesting and promising direction for applicability of this surface modification strategy for future biomedical research on anti-inflammatory/anti-microbial cell-material interactions.