Synthesis of polyamide-6@cellulose microfilms grafted with N-vinylcaprolactam using gamma-rays and loading of antimicrobial drugs

The goal of this work was to synthesize hybrid thin films prepared combining polyamide-6 (N6) and microcellulose (CE) at various weight ratios. Products exhibited improved mechanical properties, temperature-tunable hydrophilicity, and antimicrobial features. The obtained N6@CE films were grafted with N -vinylcaprolactam (NVCL) using gamma-rays, providing temperature responsiveness in a range of 37–38 °C. The grafting degree was studied as a function of CE percentage on the film, monomer concentration, and absorbed dose. The grafting degree increased with the percentage of CE on the film, and the maximum grafting was achieved at monomer concentration and the irradiation dose of 20% NVCL and 20 kGy, respectively. NVCL grafting was confirmed by SEM, 13 C-CPMAS NMR, FTIR-ATR, and XPS. SEM images attested formation of nanopores on the structure, caused by the grafting process, that consequently triggering on the new characteristics of the final materials. Potential performance of the composites as wound dressings was investigated in terms of their capability to loading and release of antimicrobial agents, such as vancomycin and benzalkonium chloride. NVCL grafting enhanced the uptake of both drugs, especially benzalkonium chloride, and regulated their release demonstrating antimicrobial effectiveness against Staphylococcus aureus . Graphic abstract