Session Speaker

Promising Technology in Addressing Tuberculosis Treatment - Nano Drug Delivery System
Hulda Swai, Boitumelo Semete, Yolandy Lemmer, Lebogang Katata, and Lonji Kalombo
South Africa

The aim of the TB project is to develop a polymeric anti-TB nanodrug delivery system that will improve the current inadequate therapeutic management of TB. It is envisaged that these polymeric nano-systems will enable entry, targeting, slow release and retention of the antibiotics in the cells for longer period, hence reduce the dose frequency from daily intake of antibiotics to once a week.

Our team has successfully nano encapsulated all four first line anti-TB drugs, with an encapsulation efficiency varying from 50-65% in particle of 250-400nm, using a novel multiple emulsion spray-drying technique. It was observed from in vitro release assays, that the drugs were released in a slow manner over a period of several days. Furthermore, we have performed intracellular drug delivery studies in CaCo-2 cells, human colonic adenocarcinoma cell line and U937 cells, a human leukemic monocyte lymphoma cell line. The results indicate that the particles are taken up by the cells within 30 minutes and in the case of the U937 cells, these particles are released from the phagosomes into the cytoplasm. Thus based on these results, intracellular delivery of the drugs will be feasible. Furthermore, we have illustrated that the bacterial growth index in THP-1 cells treated with encapsulated RIF was reduced significantly when compared to that of cells treated with free Rifampicin. Extra cellular bacteria were also killed by the encapsulated drug over a period of time. In addition drug release was observed in vivo over a period of 6 days and the MIC for RIF and INH was maintained over this period. We are now working on targeting this nanoparticles using aptamer technology.