In such a strategy, heparin would play a dual role as an antimalarial and as a targeting element for drug-loaded nanoparticles that would act by binding to infected red blood cells. The study published in Nanomedicine was carried out by researchers from the Institute for Bioengineering of Catalonia (IBEC), the ISGlobal research centre CRESIB and the University of Barcelona.
Heparin electrostatically adsorbed onto positively charged liposomes loaded with the antimalarial drug primaquine achieved three times the activity of the encapsulated drug alone in P. falciparum cultures. At heparin concentrations lower than those inducing anticoagulation of mouse blood in vivo, the improved parasiticidal activity was found to be the combined result of two distinct activities: that of free heparin as an antimalarial, and that of liposome-bound heparin as a targeting element for the encapsulated drug primaquine.
Using confocal fluorescence and transmission electron microscopy, the researchers observed that heparin permeated the intracellular parasites 30 minutes after being added to the infected red blood cells.
“These results open the door to improving antimalarials with heparin because of its combined activity as both a drug and as a specific targeting element for other antimalarial agents,” says study coordinator Xavier Fernández-Busquets, researcher at ISGlobal and IBEC. “However, more research is needed to determine the clinical role of heparin in patients infected with Plasmodium species.”
Article reference: Marques J, Moles E, Urbán P, Prohens R, Busquets MA, Sevrin C, Grandfils C, Fernàndez-Busquets X. (2014). “Application of heparin as a dual agent with antimalarial and liposome targeting activities towards Plasmodium-infected red blood cells.” Nanomedicine, 10, 8, p1719–1728