Search

A facile and greener methodology to obtain pure chitosan-based 3D porous structures in the form of monoliths and films is proposed. It is based on a modified evaporation-induced phase separation process in a chitosan solution precursor. In this approach, a deep eutectic solvent (DES) is used as the nonsolvent system and an ecofriendly, cost effective, simple and versatile alternative for the production of highly structured chitosan materials. The porous heterogeneous structure can be fine-tuned by varying the chitosan content in the precursor solution and chitosan/DES ratio, and enabled the structured polymer to absorb large amounts of water to form hydrogels. This is a versatile and unexplored approach to design porous chitosan with tailored morphology in the absence of crosslinkers, which, based on preliminary studies on V. cholerae biofilm formation, is expected to open new avenues for various applications in biomedical, catalysis, water purification, filtration and other areas where the control of bacterial biofilm formation is critical., Competing Interests: Declaration of competing interest The authors declare that there is no conflict of interest., (Copyright © 2020 Elsevier B.V. All rights reserved.)

The relationship between electrical conductivity, structure and antibacterial properties of chitosan-silver nanoparticles (CS/AgnP) biocomposites has been analyzed. To test the film's antimicrobial activity, Gram-positive and Gram-negative bacteria were studied. The interactions between silver nanoparticles with chitosan suggest the formation of silver ions which plays a major role in nanocomposite's bactericidal potency. In CS/AgnP biocomposites, the bactericide effectiveness increases by increasing AgnP concentrations up to 3 wt%, which is close to the electrical percolation threshold of ca. 3 wt%. As the AgnP concentration increases above this threshold, the bactericidal potency is greatly diminished. The elucidated correlation between electrical conductivity and antibacterial activity could be useful in the design of other nanocomposites that involve polymeric-based matrices., (Copyright © 2013 Elsevier B.V. All rights reserved.)