Cotton Fabrics with Prolonged Antibacterial Activity: Formation and Properties of Cotton Xanthate-Al(III)-Tetracycline Complex

Abstract

Cotton fabrics with prolonged antibacterial activity were prepared by coupling the tetracycline (Tc) to fabrics via chelate bonds in the presence of Al (III) ion. To enhance the binding capacity of cotton via chelation, cotton was chemically modified with carbon disulfide in alkaline media to form xanthate groups. The coupling method greatly affected the binding of Tc to cotton xanthate (CX). In a one-bath process, where CX was treated with Al(III)-Tc solution in one step, binding of Tc took place readily and effectively with about 90 mg Tc/g CX on the average. In the two-bath process, CX was reacted with the solution of Al(III) ion in the first step to produce CX-Al(III) complex, which was isolated and reacted with a solution of Tc in the second step. The amount of binding was much lower than that from the one-bath process. The resulting product, CX-Al(III)-Tc complex, had a bright-yellow color and maintained the textile nature of the fabric. Release of Tc from CX-Al(III)-Tc, which was carried out by batch and flow methods, was almost constant during the first 6 hours. Antibacterial activity of CX-Al(III)-Tc was tested against Bacillus subtilis and Escherichia coli and it showed prolonged activity in comparison with that of free Tc.