The study specifically concentrated on chitosan extracted from chitin in the carapaces of insects and crustaceans. The biopolymer was first discovered in 1859 but only recently has it become possible to establish its production within desired parameters, when researchers from the Bioengineering Center of RAS designed narrow-dispersion chitosan. This gave an opportunity to modern scientists to customize the biological properties of certain types of the biopolymer.
"We found that some forms of chitosan are toxic. They can disrupt the membranes of pathogenic microorganisms" explained Associate Professor of the Department of Microbiology Pavel Zelenikhin. "It is currently known that chitosan is effective against Klebsiella, Staphylococcus and Pseudomonas. Some forms of chitosan were also discovered to have antifungal properties".
The list of diseases caused by the aforementioned pathogens is very long. Klebsiella can cause pneumonia, urogenital infections, conjunctivitis, meningitis, septicemia, and intestinal infections. The same is true for Pseudomonas. Staphylococci (specifically Staphylococcus aureus) are well-known as the causes of many inflammatory infections.
To identify the effectiveness of chitosan on pathogenic microorganisms, the biopolymer was added to a suspension containing bacteria, followed by incubation (ranging between 30 - 120 mins) and supply of a colorant, which selectively marked dead cells; it was then possible to count the death toll cytometrically.
Following in-depth studies on biochemical capabilities of the biopolymer, the authors uncovered that chitosan destroys up to 90% of pathogens in selected cell cultures. It is especially valuable because no toxic effects on healthy cells have been observed.