An isoniazid analogue promotes Mycobacterium tuberculosis-nanoparticle interactions and enhances bacterial killing by macrophages.

Nanoenabled drug delivery systems against tuberculosis (TB) are thought to control pathogen replication by targeting antibiotics to infected tissues and phagocytes. However, whether nanoparticle (NP)-based carriers directly interact with Mycobacterium tuberculosis and how such drug delivery systems induce intracellular bacterial killing by macrophages is not defined. In the present study, we demonstrated that a highly hydrophobic citral-derived isoniazid analogue, termed JVA, significantly increases nanoencapsulation and inhibits M. tuberculosis growth by enhancing intracellular drug bioavailability. Importantly, confocal and atomic force microscopy analyses revealed that JVA-NPs associate with both intracellular M. tuberculosis and cell-free bacteria, indicating that NPs directly interact with the bacterium. Taken together, these data reveal a nanotechnology-based strategy that promotes antibiotic targeting into replicating extra- and intracellular mycobacteria, which could actively enhance chemotherapy during active TB.

Experimental design as a tool to evaluate chlorogenic and caffeic acids extracted from Cecropia glaziovii Sneth.

The effects of different parameters, including ethanol concentration, time of drug:solvent contact, temperature and the presence of a preservative, on chlorogenic acid (CGA) and caffeic acid (CFA) yields in Cecropia glaziovii Sneth extracts were investigated using an experimental design. In order to quantify the phenolic acids in these extracts a high-performance liquid chromatography-diode array detection (HPLC-DAD) method was developed and validated. Extracts with 80% ethanol presented a higher CGA content, but low amounts of CFA. Extracts with 20% ethanol showed a higher CFA concentration, but a sharp reduction in CGA extraction yield. The presence of a preservative, under the same extraction conditions, resulted in a slight difference or no difference in the CGA and CFA extraction yields. When the temperature was controlled at refrigerator or room temperature, a slight alteration in the concentrations of the phenolics studied was observed. The present approach can be applied in order to determine the optimum conditions for the preparation of C. glaziovii Sneth extracts based on CGA or CFA extraction yield as a chemical marker.