Functionalization of cotton gauzes with poly(N-vinylimidazole) and quaternized poly(N-vinylimidazole) with gamma radiation to produce medical devices with pH-buffering and antimicrobial properties

Poly(N-vinylimidazole) and its quaternized counterpart were successfully grafted onto cotton gauzes by performing radical polymerization reactions of N-vinylimidazole using high energy γ-radiation derived from a ⁶⁰Co radioactive as a clean initiator method. The obtained materials were then characterized by FTIR, DSC, TGA, and SEM to confirm the presence of the functional polymer in the gauzes. Additionally, pH titrations were performed to the solid substrates to evaluate their acid–base properties confirming that the modified gauzes behave as a polyelectrolyte buffer acid–base system with a pKa ≈ 5.6. Furthermore, to evaluate the applicability of the gauzes, elongation tests (ASTM-D5035) were performed to the pristine and the modified gauzes to evaluate their mechanical performance, finding that the mechanical properties of the gauzes were not significantly changed after the modification procedure. Finally, bacterial growth inhibition and hemolysis tests were performed to assess the antimicrobial performance of the gauzes and their biocompatibility, having found that these medical devices are effective in inhibiting the growth of S. aureus while proving non-hemolytic to human erythrocytes.