ANTIBACTERIAL ACTIVITY OF SELECTIVELY OXIDIZED LYOCELL FIBERS

Abstract

The purpose of this research was to study antibacterial activity of selectively oxidized lyocell fibers with incorporated silver particles against gram (+) and gram (-) pathogens. Antibacterial properties were accomplished by incorporation of silver ions into modified lyocell fibers by chemisorption from aqueous silver nitrate solution. In order to improve sorption properties of lyocell fibers, the selective TEMPO-mediated oxidation, i.e. oxidation with sodium hypochlorite and catalytic amount of sodium bromide and 2,2´,6,6´-tetramethylpiperidine-1-oxy radical (TEMPO), was applied. The influence of oxidation conditions оn the amount of sorbed silver, and thus on the degree of antibacterial activity was determined. It was found that the maximum amount of sorbed silver was 0.996 mmol/g cell. The antibacterial activity of the TEMPO-oxidized lyocell fibers with silver particles was confirmed in vitro against two strains: Staphylococcus aureus (ATCC 25923) and Escherichia coli (ATCC 25922). The silver-loaded TEMPO-oxidized lyocell fibers showed better antimicrobial activity against strain Staphylococcus aureus.