Chitosan has a number of commercial and possible biomedical uses. More controversially, chitosan has been asserted to have use in limiting fat absorption, which would make it useful for dieting, but there is evidence against this. A common method for the synthesis of chitosan is antibacterial activity of chitosan pdf deacetylation of chitin using sodium hydroxide in excess as a reagent and water as a solvent. The reaction occurs in two stages under first-order kinetic control.
It is not approved by FDA for drug delivery though. Nanofibrils have been made using chitin and chitosan. The agricultural and horticultural uses for chitosan, primarily for plant defense and yield increase, are based on how this glucosamine polymer influences the biochemistry and molecular biology of the plant cell. The cellular targets are the plasma membrane and nuclear chromatin. It is one of the most abundant biodegradable materials in the world.
EPA-approved, biodegradable chitosan products are allowed for use outdoors and indoors on plants and crops grown commercially and by consumers. The natural biocontrol ability of chitosan should not be confused with the effects of fertilizers or pesticides upon plants or the environment. Chitosan active biopesticides represent a new tier of cost-effective biological control of crops for agriculture and horticulture. The biocontrol mode of action of chitosan elicits natural innate defense responses within plant to resist insects, pathogens, and soil-borne diseases when applied to foliage or the soil. Chitosan increases photosynthesis, promotes and enhances plant growth, stimulates nutrient uptake, increases germination and sprouting, and boosts plant vigor. Agricultural applications of chitosan can reduce environmental stress due to drought and soil deficiencies, strengthen seed vitality, improve stand quality, increase yields, and reduce fruit decay of vegetables, fruits and citrus crops .
Horticultural application of chitosan increases blooms and extends the life of cut flowers and Christmas trees. Chitosan has a rich history of being researched for applications in agriculture and horticulture dating back to the 1980s. By 1989, chitosan salt solutions were applied to crops for improved freeze protection or to crop seed for seed priming. NASA confirmed chitosan elicits the same effect in plants on earth. Nontoxic, low molecular weight chitosan polymer solutions appear to be safe enough for broad-spectrum agricultural and horticultural uses.
In 2008, the EPA approved natural broad-spectrum elicitor status for an ultralow molecular active ingredient of 0. A natural chitosan elicitor solution for agriculture and horticultural uses was granted an amended label for foliar and irrigation applications by the EPA in 2009. Given its low potential for toxicity and abundance in the natural environment, chitosan does not harm people, pets, wildlife, or the environment when used according to label directions. Chitosan causes the fine sediment particles to bind together, and is subsequently removed with the sediment during sand filtration. Chitosan is among the biological adsorbents used for heavy metals removal without negative environmental impacts.
Chitosan hemostatic products reduce blood loss in comparison to gauze dressings and increase patient survival. The chitosan salts are biocompatible and biodegradable making them useful as absorbable haemostats. The chitosan salt may be placed on an absorbable backing. In addition to salts, hydrogel-based chitosan bandages have been developed to treat burn wounds. Burns are similar to other wounds, but are problematic because they are associated with membrane destabilization, energy depletion, and hypoxia, all of which can cause severe tissue necrosis if not treated properly or quickly enough. Chitosan-gelation bandages using nanofibrin have been shown to be more durable than ointments, while still allowing gas exchange at the cell surface. This positive charge comes from protonation of its free amino groups.
Lack of a positive charge means chitosan is insoluble in neutral and basic environments. However, in acidic environments, protonation of the amino groups leads to an increase in solubility. The implications of this are very important to biomedical applications. This molecule will maintain its structure in a neutral environment, but will solubilize and degrade in an acidic environment. This means chitosan can be used to transport a drug to an acidic environment, where the chitosan packaging will then degrade, releasing the drug to the desired environment. One example of this drug delivery has been the transport of insulin.