Bacterial behaviors on polymer surfaces with organic and inorganic antimicrobial compounds.

Infection of medical polymers is often caused by bacterial adherence and bio-film formation, and it is one of the major clinical complications causing a high rate of mortality and morbidity. In this study, it was investigated that differences of organic and inorganic antimicrobial reagents incorporated into polymers for bacterial adherence and bio-film formation. Our experimental results show adhesion of bacteria and bio-film (gram positive Staphylococcus aureus and gram negative Escherichia coli) are evidently reduced by adding organic antimicrobial reagents into PVC. However, inorganic antimicrobial reagents can not make much difference in bacterial bio-film formation on their polymers' surface. Although the surface containing inorganic antimicrobial reagents has excellent ability in killing bacteria, the amount of Escherichia coli on samples surface is no less than that on the control sample during bacterial adhesion due to both various hydrophilicity and different antibacterial mechanisms on the surface. Furthermore, bacterial bio-film formation on various hydrophilic samples is investigated, and it is observed that organic and inorganic antimicrobial compounds have much different effect on surface hydrophilicity. As a result, hydrophilicity becomes a major factor for bacterial adhesion and bio-film.