Chitin is a natural sugar-like polysaccharide found in crab and shrimp shells that is formed by glucosamine and N-acetyl glucosamine linked in a glycoside structure. Its natural rod-like and positively charged alpha-nanocrystalline structure can be separated from the raw material chitin into a 240 nm x 5 nm x 7 nm nanofibrillar form. These nanocrystals exhibit an exceptionally high surface area, up to 400 m2/g, and demonstrate relevant biological significance because they are able to activate fibroblast proliferation and cytokine production, favoring giant cell migration, macrophage activation and neovascularization.
Due to their molecular conformation and chemical-physical activity, chitin nanofibrils (CN) are capable of establishing ionic bonds with water, similar to yaluronic acid (YA). In addition, they are capable of forming complexes with active ingredients for delivery to different sites in a controlled-release manner, depending on the vehicle selected.
Functional skin care ingredients generally are delivered topically to the epidermis or dermis via the outer layer of the skin. To this purpose, one naturally derived, industrially obtained CN was examined for its delivery and active benefits. Having the same backbone as YA, CN is strongly hydrophilic and is therefore capable of attracting and binding molecules of water. It also forms stable ionic bonds with glycosaminoglycans (GAGs), which are negatively charged at the sulfate location, in addition to combining with various hydro- and lipid-soluble active ingredients commonly used in cosmetics.