Cellulose Acetate Based Material with Antibacterial Properties Created by Supercritical Solvent Impregnation

Supercritical CO2 was used as a green solvent and impregnation medium for loading cellulose acetate beads with carvacrol in order to obtain a biomaterial with antibacterial properties. Supercritical solvent impregnation was performed in a high-pressure view cell at temperature of 50 degrees C and pressures of 10, 21, and 30 MPa with the processing time ranging from 2 to 18 h. The rate of impregnation increased with the pressure increase. However, maximum impregnation yield (round 60%) was not affected by the pressure applied. Selected samples of the impregnated cellulose acetate containing 6-60% of carvacrol were proven to have considerable antibacterial effect against Gram-positive and Gram-negative bacterial strains including methicillin-resistant Staphylococcus aureus which causes severe infections in humans and animals. In addition, cellulose acetate beads containing 6.0-33.6% of carvacrol were shown to have a porous structure with submicron pores which is of interest for the controlled delivery applications.