ABSTRACT
The blood-brain barrier (BBB) prevents the passage of many drugs that target the central nervous system (CNS). The BBB represents a structure with a complex cellular organization that separates the brain parenchyma from the systemic circulation. The BBB acts not only as a mechanical barrier but also as a metabolic barrier because of the presence of numerous enzymes that are able to inactivate xenobiotics potentially harmful to the CNS. On the other hand, many drugs, such as anti-infectious drugs, antineoplastics and a number of drugs for the treatment of neurological or psychiatric diseases, have to circumvent the BBB and reach their targets in the CNS. An application of nanoparticles as drug carriers can be considered as one of the possible strategies of drug delivery to the CNS. The application of nanomaterials as drug carriers have a number of advantages, especially targeted biodistribution and controlled release and thus, increased bioavailability and decreased toxicity. Currently, various polymer materials are preferred as nanocar-riers because of their compatibility, inertness, and biodegradability. This 132contribution is focused on nanoformulations of various classes of drugs, the site of action of which is in the CNS, that were prepared using polymers of natural origin and their semisynthetic modifications representing a class of biocompatible and biodegradable carriers ensuring better therapeutic efficiency and toxicity profile of drugs.
