A new hydrogel-based drug delivery system that releases the drug over a sustained period of time might help change the way immunosuppressant drugs are given to organ transplant patients to prevent graft rejection. Scientists have created a biomaterial loaded with the immunosuppressant drug tacrolimus which detects the immune response from the transplant site and then starts delivering the drug for months on end1.
Working on rats, researchers from the Institute for Stem Cell Biology and Regenerative Medicine (inStem) in Bangalore along with scientists from Switzerland and USA injected the hydrogel-drug combo under the skin after a transplant surgery. The combo detected the immune response and began controlled release of tacrolimus to where it was needed in the transplanted graft. One injection of the hydrogel-drug combo prevented graft rejection for more than 100 days as against 33.5 days for patients receiving only tacrolimus.
Toxicities associated with delivering immunosuppressants as well as side effects of suppressing the immune system – such as susceptibility to infections – has been a challenge in organ transplantation.“Our vision is to create a novel approach where drug delivery systems release drugs in response to the disease-severity,” says one of the researchers Praveen Kumar Vemula from inStem.
The biomaterial could also be used for localized treatment of other inflammatory diseases such as psoriasis, arthritis, and cancer, he adds.
1. Gajanayake, T. et al. A single localized dose of enzyme-responsive hydrogel improves long-term survival of a vascularized composite allograft. Sci. Transl. Med. (2014) doi: 10.1126/scitranslmed.3008778