Intracellular delivery of nano-formulated antituberculosis drugs enhances bactericidal activity

Abstract

Tuberculosis kills more people worldwide than any other infectious disease. Treatment requires multiple drug therapy administered over long periods (6–24 months). The emergence of multidrug-resistant strains is a major problem, and with few new drugs in the pipeline, a novel modus operandi is urgently required. Solid drug nanoparticles (SDNs), a new development in nanomedicine, offer a fresh therapeutic approach. Here, we show that SDNs are more effective (50-fold) at killing pathogenic mycobacteria than aqueous forms of the same drug and can target mycobacteria internalised by macrophages, where bacilli reside. We demonstrate synthesis of dual and triple drug loaded SDNs, facilitating combination tuberculosis therapy. Our results suggest that by employing SDNs of existing antibiotics, it may be possible to improve drug delivery and therefore reduce drug dosage to lessen side effects and fight drug resistance.