Hybrid materials based on chitosan functionalized with green synthesized copper nanoparticles: Physico-chemical and antimicrobial analysis

DIEGO ALEJANDRO MARIN-SILVA; NELSON ROMANO; L.C. DAMONTE; LEDA GIANNUZZI; A.PINOTTI

INTERNATIONAL JOURNAL OF BIOLOGICAL MACROMOLECULES

ELSEVIER SCIENCE BV

Lugar: Amsterdam; Año: 2023

0141-8130

Recently, the development of materials with antimicrobial properties has become achallenge under scrutiny. The incorporation of copper nanoparticles (NpCu) into a chitosanmatrix appears to represent a viable strategy to contain the particles and prevent theiroxidation. Regarding the physical properties, the nanocomposite films (CHCu) showed adecrease in the elongation at break (5%) and an increase in the tensile strength of 10%concerning chitosan films (control). They also showed solubility values lower than 5% whilethe swelling diminished by 50%, on average. The dynamical mechanical analysis (DMA) ofnanocomposites revealed two thermal events located at 113° and 178°C, which matchedthe glass transitions of the CH-enriched phase and nanoparticles-enriched phase,respectively. In addition, the thermogravimetric analysis (TGA) detected a greater stabilityof the nanocomposites. Chitosan films and the NpCu-loaded nanocomposites demonstratedJournal Pre-proofJournal Pre-proofexcellent antibacterial capacity against Gram-negative and Gram-positive bacteria, provedthrough diffusion disc, zeta potential, and ATR-FTIR techniques. Additionally, thepenetration of individual NpCu particles into bacterial cells and the leakage of cell contentwere verified by TEM. The mechanism of the antibacterial activity of the nanocompositesinvolved the interaction of chitosan with the bacterial outer membrane or cell wall and thediffusion of the NpCu through the cells.These materials could be applied in diverse fields of biology, medicine, or food packaging.