Scientists have formulated nano sized particles out of semi-synthetic starch particles called chitosan. HIV infected cells, when exposed to drugs encapsulated by chitosan, absorb about 90 per cent of the drug. Chitosan also leads to an immune response in the cell.
Drugs that are being used in Anti Retroviral Therapy in HIV cause many unwanted side effects and do not stay in the body long enough for maximum effect.
“So, chitosan supplements the effects of the drug, Saquinavir, we found,” says Dr Umamaheswari K, Associate Dean at Department of Medical Nanotechnology in Sastra University. She is the corresponding author of the paper published recently on the work done by a team of scientists from Jawaharlal Nehru Centre for Advanced Scientific Research and her lab.
The scientists had cultured cells infected with HIV. Just the drug Saquinavir was added to one tissue culture while chitosan carriers loaded with Saquinavir, was added to another. There was a control of cells where nothing was added while to another just chitosan was added.
The amount of drug uptake was measured by a technique called as Flow Cytometry. Uptake of chitosan carriers loaded with the drug was found to be 90 per cent in cells compared to just the drug. By itself, chitosan was recognised by the immune system and triggered a mild immune response, something that the drug does to a greater degree. Dr Umamaheswari says, “In a patient with AIDS, adverse effects of the drug are not seen easily as he already has several complications due to the illness. Since the drug is easily metabolised, its efficacy is not realised in the body. Being linked to chitosan will prevent Saquinavir from causing side effects and it will not be easily removed from the body.” Prof Uday Kumar Ranga, another scientist involved in the study from Molecular Biology and Genetics Unit at the Jawaharlal Nehru Centre for Advanced Scientific Research in the city thinks the work is at an early stage. He says, “Our work is too preliminary. What we have shown is an efficient delivery of anti-HIV drugs to the T-cell lines (a type of immune cells) in the laboratory. We are yet to demonstrate that the drug can be delivered predominantly to the CD4 (specialised T cells) cells as compared to cells of other lineages and this strategy can work in the body of an experimental animal.”
He explains the need for animal trials and then comes the real task of testing this strategy in human beings which is a long and hard journey.
He adds, “The mouse model that we optimised at JNCASR is a simple, inexpensive and appropriate one for testing drug delivery.”