Nanoparticles: The New Weapon Against Tuberculosis?

Tuberculosis (TB) has become the most serious bacterial threat with the development of urbanization in the early 19^th century. Recent intensification of world globalization has worsened this scenario, making mycobacterial disease more widespread. Even though 95% of TB cases still occur in developing countries, people that are infected with TB can travel to industrialized countries dramatically raising their number of new cases.

As a result of all that in 2011 there were 1,4 million deaths,  8,7 million new cases a year, 0,5 million of them being multi-drug resistant (MDR) TB. World medicine has provided great improvements in fighting the disease and the 50’s new antibiotic era even brought some hopes that the disease could easily be eradicated. These predictions proved wrong and to date we still lack an effective vaccine and highly reliable instruments for latent and active TB diagnosis. TB chemotherapy is able to cure 87% of the cases but is expensive and requires a long treatment (at least 6 months, 24 months for MDR TB) that is connected with patient not compliance, regarded as the main cause of MDR TB. In periods of economic turmoil like the present this is especially worrying since the cost of treating a MDR TB case can be as high as 500.000 dollars , much higher than the cost of treating susceptible TB.

There is therefore a desperate need for new drugs against TB and new methods to diagnose and successfully treat the disease. Among those, of particular interest against MDR TB, seems to be the use of nanoparticles encapsulating drugs. These are usually made of biodegradable polymers that are able to both release the drug in a sustained fashion and to target the main cell type infected by the mycobacterium: the macrophage. In this way it seems possible to decrease the dosage of drugs and therefore lowering toxicity that is one of the main problems for treating MDR TB.