The Impact of Cross-linking Mode on the Physical and Antimicrobial Properties of a Chitosan/Bacterial Cellulose Composite

Abstract

The bacteriostatic performance of a chitosan film is closely related to its ionic and physical properties, which are significantly influenced by the mode of cross-linking. In the current work, chitosan with or without bacterial cellulose was cross-linked with borate, tripolyphosphate, or the mixture of borate and tripolyphosphate, and the composite films were obtained by a casting of dispersion. Mechanical measurements indicated that different modes of cross-linking led to varying degrees of film strength and elongation increases, while the films treated with the borate and tripolyphosphate mixture showed the best performance. Meanwhile, changes in the fractured sectional images showed a densified texture induced by cross-linkers, especially for the borate and tripolyphosphate mixture. Measurements of Fourier transform infrared showed the enhanced interaction between the matrix polymers treated by borate, confirmed by a slight increase in the glass transitional temperature and a higher surface hydrophobicity. However, the reduced antimicrobial efficiency of composite films against E. coli, B. cinerea, and S. cerevisiae was obtained in cross-linked films compared with chitosan/bacterial cellulose films, indicating that the impact on the antimicrobial function of chitosan is a noteworthy issue for cross-linking.

Tannic-Acid-Cross-Linked and TiO2-Nanoparticle-Reinforced Chitosan-Based Nanocomposite Film

“…Chitosan has fair uses in food packaging and product storage, even though weak mechanical and barrier properties restrict its bulk use as an alternative to synthetic plastics [ 20 , 21 , 22 , 23 , 24 ]. Chitosan-based film’s limitations can be improved using chemical cross-linkers and physical reinforcement with nanofillers [ 18 , 25 ]. A previous study was carried out based on physical cross-linking of chitosan to improve its physical properties [ 26 , 27 , 28 ].…”

pH‐Responsive Studies of Bacterial Cellulose /Chitosan Hydrogels Crosslinked with Genipin: Swelling and Drug Release Behaviour

“…The thin microfibrils of BC are significantly smaller than those in plant cellulose, making BC much more porous than plant cellulose . The high aspect ratio of BC fibrils provided BC with high swelling ability, which resulted in high water holding capacity …”

“…Crosslinkers such as glutaraldehyde, tripolyphosphate, ethylene glucol, diglycidyl ether and diisocyanate have been used. However, these synthetic crosslinking reagents are all more or less cytotoxic, may impair the biocompatibility of hydrogels delivery systems and their crosslinked products have been found to show limited stability . Thus, there is a need for a natural crosslinking agent that is nontoxic and that forms stable and utterly biocompatible crosslinked products.…”

Antimicrobial Polymer-Based Materials for Food Packaging Applications

“…The cross-linking increased the mechanical properties, such as the tensile strength, and composites crosslinked with the borate/tripolyphosphate mixture exhibited the best properties. However, the antibacterial activity was reduced compared to non-crosslinked composites [22].…”