ABSTRACT
Erythrocyte function has broadened to include oxygen, carbon dioxide, hydrogen sulphide and nitric oxide exchange as well as immune clearance and clearance of other soluble blood components such as cytokines. These are emerging as a highly biocompatible microparticulate drug carrier system. It offers a greater potential related to its biodegradability, non-pathogenicity, non-immunogenicity, biocompatibility, self-degradability along with high drug loading efficiency. The use of erythrocytes as biological carriers offers an alternative to other carrier systems such as liposomes or nanoparticles that have been used for the encapsulation of different drugs, enzyme systems and peptides with therapeutic activity. These drug carriers are particularly proficient to release drugs in systemic circulations for a week or a month. They have the capacity to accommodate a large amount of traditional drugs from the biological source. These carriers have also been used for encapsulating and delivering DNA materials, gene, antibodies, antigens, proteins and peptides and contrasting agents. Resealed erythrocytes have been successfully evaluated with thousands of therapeutic applications in humans proving the safety and efficacy of the treatments. The main advantage of carrier erythrocytes is that they act as a true drug delivery system, with a change in the kinetic properties of the substances, and they achieve selective distribution to different organs and tissues, especially the phagocytic cells of the mononuclear phagocyte system. This chapter includes physicochemical properties, methods of drug encapsulation in erythrocytes and their applications.
