Adhesion of different bacterial strains to low-temperature plasma-treated sutures.

In this study, five different bacteria with their different strains were isolated and characterized. Contact angles were measured by a captive-bubble technique. Surface-free energies were calculated from the contact angles. Hydrophobicities also were evaluated by rho-xylene adhesion. The zeta potentials and surface charges of the bacteria were obtained. The contact angles of the gram-positive bacteria and gram-negative bacteria were within the range of 48 degrees-69 degrees and 43.5 degrees-55 degrees, respectively, while corresponding surface-free energies were in the limits of 45.4-51.6 erg/cm-2 and 51.7-61.8 erg/cm-2, respectively. The rho-xylene adhesions were parallel to hydrophobicities defined by contact angles, and 32.2-80.3% and 2.3-36.6% for the gram-positive bacteria and gram-negative bacteria, respectively. The zeta potentials for these bacteria were from -650.2 to +17.5 mV and from -159.6 to -6.0 mV, respectively. Most of the bacteria were negatively charged, except the CNS-2 and CPS-1 strains. In the second part of the study, attachment of these bacteria to Vicryl sutures and their DMAEMA and AAc plasma-treated forms were investigated. Hydrophobic bacteria attached more to hydrophobic Vicryl sutures. Both plasma treatments caused significant drops in bacterial attachment in most cases. Effects of AAc plasma treatment were more pronounced.