Native and cationic cellulose nanofibril films enriched with avocado seed compounds as a green alternative for...

Cellulose nanofibrils (CNF) show great potential for skin wound care and healing due to their biocompatibility, non-cytotoxicity, and high swelling with good mechanical stability. In the presented study, for the first time native and cationized cellulose nanofibrils were used in combination with avocado seeds extracts obtained with different extraction methods (ASE), as an alternative to a well-known antibiotic, Clindamycin, to produce films with high and long-lasting antimicrobial efficacy. The swelling capacity of prepared films and extracts/antibiotic release kinetics were studied at different pH values to evaluate pH response behavior. All developed films exhibited high bacteriostatic and bactericidal activity against Gram-negative Escherichia coli and G-positive Staphylococcus aureus, resulting in up to 100 % bacterial reduction with the log reduction factor up to 5.64 or 6.50, at 14.2 mg of avocado seed extract or clindamycin integrated in the 1 cm² of CNF film. The high swelling capacity (up to 65.67 %) and stability of avocado seed extracts-enriched CNF films provide a suitable moisture environment and a sustainable release (up to 40.98 % in 48 h) of bioactive compounds. The prepared antibacterial films' chemical and morphological characteristics and pH-responsive behavior proved the potential applications in the cosmetics, biomedicine, and pharmaceutical industry.