Chapters authored
Antimicrobial Activity of Chitosan Membranes Against Staphylococcus Aureus of Clinical Origin
Healthy human skin has beneficial microflora and many pathogens causing infections. Staphylococcus aureus is the most prevalent and can have multiresistance to antibiotics. Chitosan is a polysaccharide composed of glucosamine and N-acetyl-D-glucosamine, which is biodegradable and has antimicrobial activity. As part of a national scientific research project for the development and application of biomaterials, we decided to study the effect of different membranes based on chitosan against strains of S. aureus isolated from infected ulcers. The study found that seven of nine strains of S. aureus are sensitive to rifampin and the least eight of nine strains were multiresistant to more than ten antibiotics. All chitosan-based membranes confirm its antimicrobial effect on direct contact with an increase in its diameter. The contact area of the membranes is increased according to the concentration of chitosan. The highest average area increase was the chitosan membranes with honey and glycerin, 88.32%. Chitosan membranes have shown their effectiveness against S. aureus strains of clinical origin. Thus, these materials can be applied for the treatment of chronic ulcers without toxic hazards and resistance caused by antibiotics.
Part of the book: The Rise of Virulence and Antibiotic Resistance in Staphylococcus aureus
Chitosan and Xyloglucan-Based Hydrogels: An Overview of Synthetic and Functional Utility
The development of new strategies for wound healing has resulted in the design of biomedical devices using polymers of natural origin. Hydrogels are biomaterials formed by three-dimensional polymeric networks that can retain large amounts of water or biological fluids, and smooth texture similar to living tissue. Chitosan is a linear polysaccharide, (1-4)-2-amino-2deoxy-ß-D-glucan, which has desirable features such as biocompatibility, non-toxicity, hemostasis and antibacterial character. Xyloglucans have different applications in tissue engineering for their physicochemical properties, biocompatibility and control of cell expansion. Hydrogels had been made of homogeneous mixtures prepared of chitosan and purified xyloglucan, followed by a freeze-drying process to develop a flexible and porous structure. Additionally, their mechanical properties such as porosity, solubility, biodegradation, and the antibacterial activity of the hydrogels are studied. The results suggest that the incorporation of xyloglucan favors the characteristics from chitosan-based hydrogels, providing a promising alternative for application in biomaterials with antimicrobial activity.
Part of the book: Chitin-Chitosan