Erythrocytes as Carriers: From Drug Delivery to Biosensors

Abstract

Drug delivery using natural biological carriers, especially erythrocytes, is a rapidly developing field. Such erythrocytes can act as carriers that prolong the drug's action due to its gradual release from the carrier; as bioreactors with encapsulated enzymes performing the necessary reactions, while remaining inaccessible to the immune system and plasma proteases; or as a tool for targeted drug delivery to target organs, primarily to cells of the reticuloendothelial system, liver and spleen. To date, erythrocytes have been studied as carriers for a wide range of drugs, such as enzymes, antibiotics, anti-inflammatory, antiviral drugs, etc., and for diagnostic purposes (e.g. magnetic resonance imaging). The review focuses only on drugs loaded inside erythrocytes, defines the main lines of research for erythrocytes with bioactive substances, as well as the advantages and limitations of their application. Particular attention is paid to in vivo studies, opening-up the potential for the clinical use of drugs encapsulated into erythrocytes.

Keywords: carrier erythrocyte; diagnostics; drug delivery; erythrocyte; erythrocyte-bioreactor; targeted drug delivery; therapy.

Figure 1

Change in the total number of articles published in the world on the subject of erythrocyte carriers of biologically active substances, since 1973.

Figure 2

Possible modes of use of RBCs loaded with biologically active compounds and nanoparticles. MRI—magnetic resonance imaging; IHP—inositol hexaphosphate; MPH—macrophages; RES—reticuloendothelial system.