Visceral Leishmaniasis (VL) is a disease caused by the protozoan parasite Leishmania donovani. Currently, chemotherapy is the only available treatment for VL, as no vaccines exist. The most used drug, Amphotericin B, though effective, has significant side effects, particularly due to the concentration at which it is used. The goal of eradicating VL is yet to be achieved, primarily because chemotherapy is the only available option, and drug resistance is a persistent issue. New drugs and therapeutic strategies are often required as parasites adapt and become resistant to treatments, presenting an ongoing challenge.
Associate Professor at Ahmedabad University's School of Arts and Sciences Souvik Sen Gupta's research introduces a novel solution: a gold nanoparticle conjugate of Amphotericin B. In this formulation, gold forms the nanoparticle's core with Amphotericin B attached to it. Macrophages, the host cells targeted by the parasite, are known to absorb gold readily. This conjugation enhances the drug's uptake by macrophages, thus leading to some degree of selectivity in targeting the infected cells, albeit at a lower drug concentration, which reduces side effects. Using the RAW 264.7 macrophage, which imitates human host cells, Professor Sen Gupta and his group found that gold-Amphotericin B nanoparticle effectively attacked the parasite without causing harm to the host cells.
This research addresses the current limitations of Amphotericin B. Amphotericin B is currently administered in the liposomal form, wherein the drug is encapsulated in a lipid molecule and injected into the bloodstream of the patient. However, producing this liposomal formulation is expensive, making it not cost-effective. Other side effects, known as infusion reactions, can vary widely, negatively impacting several bodily functions. By attaching Amphotericin B to gold nanoparticles, the infusion reactions can be reduced by lowering the required drug dosage.
The new formulation uses citrate-coated gold nanoparticles to bind with Amphotericin B. After forming this unique biomaterial, it was characterised using techniques like dynamic light scattering and transmission electron microscopy. After testing its effects and comparing it with traditional Amphotericin B, the authors concluded that this novel formulation has potential for development as a future antileishmanial therapeutic agent.
Leishmaniasis, a neglected tropical disease, is primarily spread by the bite of infected sand flies, thriving in tropical climates. Symptoms of visceral leishmaniasis include spleen enlargement, occasional fevers, and chronic internal damage. Over time, untreated patients face severe physiological declines as the disease eats away from within. The disease is more prevalent in people below the poverty line as they do not have access to proper nutrition, which is directly related to the capability to fight any disease. The research aims to provide a more targeted, cost-effective, and less toxic treatment for leishmaniasis by utilising gold nanoparticles as a carrier for Amphotericin B, offering a breakthrough in treating this challenging disease.