Proactive Release of Antimicrobial Essential Oil from a “Smart” Cotton Fabric

Two temperature and pH responsive submicron hydrogels based on poly(N- methylenebisacrylamide), chitosan and β-cyclodextrines (PNCS/CD hydrogel) with varying poly(N-isopropylacrylamide) to chitosan ratios were synthesized according to a simplified procedure, reflecting improved stimuli responsive properties and excellent bio-barrier properties, granted by incorporated chitosan. Hydrogels were applied to cotton-cellulose fabric as active coatings. Subsequently, antimicrobially active savory essential oil (EO) was embedded into the hydrogels in order to develop temperature- and pH-responsive cotton-cellulose fabric with double antimicrobial activity, i.e., bio-barrier formation of chitosan along with the proactive release of savory EO at predetermined conditions. The influence of the hydrogels chemical composition on stimuli responsive and antibacterial properties were assessed. Both PNCS/CD hydrogels showed stimuli responsiveness along with controlled release of savory EO. The chemical composition of the hydrogels strongly influenced the size of the hydrogel particles, their temperature and pH responsiveness, and the bio-barrier forming activity. The increased concentration of chitosan resulted in superior overall stimuli responsiveness and excellent synergy between the antimicrobial activities of the hydrogel and released savory EO