Creation of composites of bacterial cellulose and silver nanoparticles: evaluation of antimicrobial activity and cytotoxicity

Abstract

Bacterial cellulose, a biopolymer synthesised by the bacteria Gluconacetobacter hansenii, has unique nanostructure, but does not possess antimicrobial effect. Chemical modification is used to provide bacterial cellulose with additional adsorption properties and antimicrobial activity. In this study, composites of bacterial cellulose and silver nanoparticles were prepared by the metal-vapour synthesis method has been obtained. Transmission electron microscopy (TEM) has shown that the size of silver particles in a nanocomposite varies from 8 to 12 nm. Using X-ray photoelectron spectroscopy, it was found that the binding energy of the Ag 3d5/2 peak is 368.2 eV, which is close to the silver characteristic in the film of bacterial cellulose in the Ag0 state. The disk-diffusion method used in this study showed that all experimental nanocomposites had pronounced antibacterial activity against Escherichia coli ATCC 25922, Staphylococcus aureus FDA 209P and acid resistant Bacillus coagulans ATCC 6633, but no fungicidal effect against Aspergillus niger ATCC, ATCC 2091 and Candida albicans АТСС 2091 was found. Extracts of a composite of silver nanoparticles and bacterial cellulose has been detected to reduce the viability of human melanoma cells (SK-Mel-1) after 48 h of cultivation to 47.4 ± 1.5% and mesenchymal stem cells (MSCs) cultures to 88.4 ± 4.6%. Studies of a nanocomposite based on bacterial cellulose and silver nanoparticles suggest that this natural polymer can be used to create medical antibacterial and antitumour materials.