This review shows some classical applications of
peptides and suggests there is great promise for the treatment of various
central nervous system diseases. Actually,
peptides are considered the new generation of biologically active tools because they are key regulators in cellular and intercellular physiological responses, which possess enormous potential for the treatment of various diseases. In spite of their clinical potential, native
peptides have seen limited use due to their poor bioavailability and low stability in physiological conditions. Moreover, most
peptide or
protein pharmaceuticals currently in use are delivered by invasive routes such as via
subcutaneous injection. Considerable efforts have been made to design new drugs based on
peptides and recent developments in technology and science have provided the means and opportunity to produce a stable as well as controlled-release form of
peptide and
protein drugs to combat poorly controlled diseases and to increase patients' quality of life. A major challenge in this regard, however, is the delivery of
peptides over the blood-brain barrier. This review gives an overview of some strategies used to improve both bioavailability and uptake of
peptide drugs for delivery into the brain. Indeed, recent findings suggest that the use of
peptides by conjugation to a
polymer such as nanoparticles can offer tremendous hope in the treatment of
brain disorders. The
polymer conjugation improves pharmacokinetics by increasing the molecular mass of
proteins and
peptides and shielding them from
proteolytic enzymes. These new strategies will create new opportunities for the future development of neurotherapeutic drugs. In the present review we have focused our attention on the
peptide controlled delivery, summarizing literature reports on the use of
peptides and nanotechnology for the treatment and diagnosis of
brain disorders.