Antibacterial effect of thiocyanate substituted poly(vinyl chloride)

Poly(vinyl chloride) (PVC) modified in different solvents by nucleophilic substitution with thiocyanate was exposed to Gram-negative bacteria of the strain Staphylococcus capitis. All modified pieces reduced the adhesion of bacteria by between 67 and 79%. More important for the bacteria suppression than the substitution rate was the ratio between thiocyanate and isothiocyanate groups. The best result was obtained with PVC modified in tetrahydrofuran/dimethylsulfoxide, containing only antibacterial active isothiocyanate groups, while inactive thiocyanate groups were absent.