Figure 1.

Structural formulas of some carbohydrates (cellulose and its derivatives, chitosan, pectin, hyaluronic acid, and alginate) and their possible modifications, on the basis of which it is possible to obtain various materials, including NPs [30,31,32,33,34,35,36,37,38]. The chemical modifications of polysaccharide nanoparticles are necessary to enhance their ability to cross the BBB and reach the target brain cells and for the attachment of targeting moieties and drugs. These modifications promote charge and active site setting, which allows nanoparticles with controlled drug release and biodegradation ability to be designed.