A novel 1,3,4-thiadiazole modified chitosan: synthesis, characterization, antimicrobial activity, and release study from film dressings

Abstract

Herein, two new polymers designated as Cs-EATT and Cs-BATT have been synthesized via linking the chitosan with the synthesized 1,3,4-thiadiazole compounds. They were characterized using ¹H,¹³C-NMR, FT-IR, TGA, Elemental analysis, Mass spectrum, and UV–vis spectrophotometer. The synthesized polymers exhibit high activity to control the growth of pathogenic bacteria (S. aureus, B. subtilis, E. coli, and P. aeruginosa), and unicellular fungi (C. albicans). The MIC values were in the range of 25–100 µg mL^–1 for Cs-EATT and 25–200 µg mL^–1 for Cs-BATT with varied clear zones. The new polymers were mixed with three film-forming agents: polyvinyl alcohol, hydroxyethyl cellulose, and carboxymethyl cellulose to form six film dressings designated as E1, E2, and E3 for Cs-EATT, and B1, B2, and B3 for Cs-BATT, respectively. The evaluation of film dressings showed that the formed films had transparency, uniformity, homogeneity, elasticity, and non-irritation pH values for skin within the normal range. The maximum percentages of Cs-E/B-ATT content were recorded for film dressings E2 and B2, with values of 92.5% and 94.9%, respectively. Also, the release percentages varied according to film dressing formulation, with values in the ranges of 83.88–93.2% for Cs-EATT and (87.7–97.35%) for Cs-EATT after 9 h.