Neuroprotective peptide drug delivery and development: potential new therapeutics.

Alzheimer's disease and related neurodegenerative disorders are prevalent among the elderly and might be considered as the plague of the 21st century. It is thus imperative to find cures for these conditions. The use of nerve growth factor proteins as neuroprotective therapeutics is limited by their hindered mobility through the blood-brain barrier. Peptides provide an attractive alternative. However, do peptide derivatives retain the activity of the entire protein? Are they stable? Would peptides cross the blood-brain barrier and what are the potential side effects? Examples are put forth to strengthen our opinion that peptides are important candidates for future drug development.