Multifunctional biocompatible films based on pectin-Ag nanocomposites and PVA: Design, characterization and antimicrobial potential

Abstract

Pectin-Ag nanocomposites with a core-shell structure are synthesized by the “green chemistry” method based on the reduction of silver nitrate with pectin (amidated, low-, or high methoxylated) in an alkaline medium at room temperature. TEM and DLS measurements show that the average size of the inorganic core (10–30 nm) and hydrodynamic diameter of the nanocomposite (284.8–649.2 nm) depend on the type of pectin. The films based on pectin-Ag nanocomposites and polyvinyl alcohol (PVA) with different molecular weight (30, 66, and 145 kDa) are obtained by casting evaporation technique. A comparative study of their mechanical, optical, degradation and antibacterial properties is carried out. The films with the smaller size of Ag nanocomposite exhibit higher antimicrobial activity against Bacillus strains. The pectin-Ag/PVA films are loaded with antibiotic kanamycin (KAN). Prolonged release of antibiotic and pronounced (up to full inhibition) antimicrobial effect of pectin-Ag/PVA/KAN films against Escherichia coli, Pseudomonas aeruginosa, Bacillus pumilus, and Bacillus subtilis is due to the formation of pectin-Ag/KAN complexes. Moreover, pectin-Ag/PVA/KAN films show high potency against resistant strains Pseudomonas aeruginosa. The obtained multifunctional films are expected to find promising applications in biomedical engineering and wound healing.