Showing posts with label Chitosan. Show all posts
Showing posts with label Chitosan. Show all posts

Monday, December 16, 2013

New antifungal composition effectively inhibits wide variety of fungi

In order to overcome resistance to antifungal variety of pathogenic fungi and yeast, researchers from the University of Alicante have developed a novel and efficient antifungal composition with pharmacological applications in agriculture and food industry, among others. 

The composition, developed and patented by the UA Research Group in Plant Pathology, is based on the combined use of chitosan, or chitosan oligosaccharides (right structure, COS), antifungal agents and additives that synergistically affect the growth of a variety of pathogenic fungi.

"Chitosan is a non-toxic biopolymer, biocompatible and naturally degradable, with antibacterial, antiviral and antifungal properties obtained from chitin, the main constituent of hard body parts of invertebrates, such as the shells of shrimp, lobsters, crabs, and other marine crustaceans, and is part of the fungal cell wall," as explained by lecturer Luis Vicente López Llorca, Director of the UA Research Group in Plant Pathology and head of the research work.

"Because many fungal pathogens develop resistance to prolonged treatment with antifungal drugs, it is desirable to find alternatives for their control in medical, agricultural and those applications in which the fungi cause damage. In clinics, pathogenic fungi resistant to antifungal drugs are a major cause of mortality in patients. Chitosan and the antifungal additives, some based on the identification of molecular targets of chitosan, contribute to produce a novel alternative to control fungal diseases and in particular antifungal resistant strains" López Llorca said.

The various experiments carried out by the research group are proof of the significant synergistic effect of the combination of chitosan (or COS) and other antifungals and ARL1 gene inhibitor, in inhibiting the growth of mold and yeast . "Chitosan is nontoxic to mammals, making it suitable for use as an antifungal in various applications," Luís Vicente López adds.

Tuesday, April 20, 2010

Chitosan could repair spinal damage - first evidence....

Polyethylene glycol (PEG) was reported to seal and repair damaged spinal cord nerve cells,  by repairing the damaged membranes of nerve cells. Researchers lead by  Richard Borgens and his team claimed that, PEG can restore the spinal cord's ability to transmit signals to the brain. However, there is one possible clinical drawback: PEG's breakdown products are potentially toxic

So, is there a biodegradable non-toxic compound that is equally effective at targeting and repairing damaged nerve membranes? Borgens teamed up with physiologist Riyi Shi and chemist Youngnam Cho, who pointed out that some sugars are capable of targeting damaged membranes. Borgens and his team  has  now come up with an interesting finding i.e.,  chitosan (see structure; source  : Wikipedia) can repair damaged nerve cell membranes. 

Having initially tested mannose and found that it did not repair spinal cord nerve membranes, Cho decided to test a modified form of chitin, one of the most common sugars that is found in crustacean shells. Converting chitin into chitosan, Cho isolated a segment of guinea pig spinal cord, compressed a section, applied the modified chitin and then added a fluorescent dye that could only enter the cells through damaged membranes.  Viewing a section of the spinal cord under the microscope, Cho was amazed to see that the spinal cord was completely dark and none of the dye had entered the nerve cells and Cho concluded that Chitosan had repaired the damaged cell membranes.

Borgens is extremely excited by this discovery that chitosan is able to locate and repair damaged spinal cord tissue and is even more enthusiastic by the prospect that nanoparticles of chitosan could also target delivery of neuroprotective drugs directly to the site of injury.
'giving us a dual bang for our buck,' says Borgens....

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