Preparation of the water-soluble chitosan-coated oxidized regenerated cellulose gauze

A water-soluble chitosan-coated oxidized regenerated cellulose (ORC) gauze was prepared by the oxidation of a viscose gauze with NO₂/CCl₄ and subsequent treatment with a solution of chitosan in aqueous acetic acid and finally neutralization with NaOH/C₂H₅OH solution. A series of C6 ORC samples with different -COOH content were prepared and coated by chitosans (CTS) with different molecular weight (Mw) of 2,000, 50,000, 100,000 (denoted as CTS1, CTS2, CTS3). FT-IR and TG suggested the formation of the amide bond between the carboxyl group of ORC and the amino group of CTS. Kjeldahl nitrogen analysis of ORC gauze treated with CTS (CTS-ORC) showed that the percentage of chitosan with the lowest Mw of 2,000 introduced on ORC surface was highest and increased with oxidation time, while chitosans with medium and high Mw showed that the maximum percentage of chitosan introduced on ORC surface occurred at the oxidation time of 8 h. The neutralized chitosan-coated ORC gauze could still maintain its original morphological form and was water-soluble, and could form a transparent gel quickly for 5 s in water. The prepared water-soluble gauze could be anticipated to possess the improved hemostatic and antibacterial properties.