Microwave-enhanced synthesis of biodegradable multifunctional chitosan hydrogels for wastewater treatment

Chitosan, a derivative of chitin, is a biodegradable polymer known of its favorable properties, applicable in medicine and industry. Commonly obtained chitosan hydrogels are of various swelling capacity, and may bind only anions losing their susceptibility to biodegradation. Hydrogels are mostly obtained using toxic crosslinkers, which pollute environment due to waste generation during their synthesis. In the present article a novel, waste-free method for obtaining chitosan hydrogels under microwave irradiation, is described. Their chemical and morphological structure, swelling properties, sorption capability of a model dye and cadmium ions are described, and kinetic studies, were carried out. Biodegradability of the obtained hydrogels was investigated with the Sturm Test method. As a result, multifunctional chitosan hydrogels with both negative and positive surface charges and increased ability of anions and cations binding, were obtained. Materials were fully biodegradable, capable to absorb high amounts of water, as well as to remove various water contaminants

Chitosan/aminoacid hydrogels with antimicrobial and bioactive properties as new scaffolds for human mesenchymal stem cells culture applicable in wound healing

Application of human mesenchymal stem cells brings a new hope for advanced wound healing. To enable cells culture and their viability maintenance, a new type of biomaterials must be developed. Scaffolds prepared from polymers of natural origin can mimic extracellular matrix. Chitosan, which is a chitin derivative, has many favorable properties like biodegradability or lack of cytotoxicity. Therefore, it is widely applied in medicine and pharmacy. Nevertheless, its chemical modification may lead to the loss of biocompatibility of the material and generate some significant problems with cells culture. In this article a novel strategy of the bioactive and antimicrobial chitosan hydrogel scaffolds is presented. As crosslinking agents non-toxic substances were used such as aspartic acid and glutamic acid. Obtained biomaterials were investigated over their chemical structure, morphology and biological activity. Performed tests using human mesenchymal stem cells confirmed bioactivity and biocompatibility, as well as antibacterial and antifungal properties

Impact of Electrospinning Parameters and Post-Treatment Method on Antibacterial and Antibiofilm Activity of Chitosan Nanofibers

Chitosan, a natural biopolymer, is an ideal candidate to prepare biomaterials capable of preventing microbial infections due to its antibacterial properties. Electrospinning is a versatile method ideally suited to process biopolymers with minimal impact on their physicochemical properties. However, fabrication parameters and post-processing routine can affect biological activity and, therefore, must be well adjusted. In this study, nanofibrous membranes were prepared using trifluoroacetic acid and dichloromethane and evaluated for physiochemical and antimicrobial properties. The use of such biomaterials as potential antibacterial agents was extensively studied in vitro using Staphylococcus aureus and Escherichia coli as test organisms. The antibacterial assay showed inhibition of bacterial growth and eradication of the planktonic cells of both E. coli and S. aureus in the liquid medium for up to 6 hrs. The quantitative assay showed a significant reduction in bacteria cell viability by nanofibers depending on the method of fabrication. The antibacterial properties of these biomaterials can be attributed to the structural modifications provided by co-solvent formulation and application of post-treatment procedure. Consequently, the proposed antimicrobial surface modification method is a promising technique to prepare biomaterials designed to induce antimicrobial resistance via antiadhesive capability and the biocide-releasing mechanism