CARBOHYDRATE HANDLES AS NATURAL-RESOURCES IN DRUG-DELIVERY

Carbohydrates, perhaps the most ubiquitous chemicals in living systems, have been traditionally associated with energy production and as building blocks. Increasingly, however, the role of carbohydrates is seen as more pervasive and sophisticated. Their involvement in and with lectins, the high affinity carbohydrate-binding non-immune proteins or glycoproteins, makes them attractive as 'handles' in drug delivery. As such, carbohydrates could partake as (1) organ or site delivery, by making use of their particular physicochemical properties, and (2) specific cell delivery, using the idea of carbohydrate receptors to route useful drugs to cell targets. The latter concept has been re-ascribed to the selectivity found in carbohydrate conjugates of ellipticine, 8-hydroxyquinoline, 6-mercaptopurine, etc. Recently, polymeric carbohydrates have been used in the development of polyvalent drugs, those that bind to a target site through multiple interactions, and in the delivery of xenobiotics through neoglycoprotein conjugates.