Hydrogel for slow release of IBD drugs
doi:10.1038/nindia.2015.106 Published online 18 August 2015
Researchers have developed a hydrogel microfibre system that can selectively adhere to ulcerative colon mucosa and deliver the necessary drugs, thus increasing the efficacy of treatment in inflammatory bowel disease (IBD)1.The researchers from Institute for Stem Cell Biology and Regenerative Medicine (inStem) in Bangalore along with counterparts from Brigham and Women’s Hospital (BWH), Massachusetts Institute of Technology (MIT) and Massachusetts General Hospital (MGH), Boston, USA have developed the drug-loaded system that selectively targets ulcerative colon mucosa cells and releases the drug only at the site of inflammation to eliminate systemic toxicity. The microfibres loaded with anti-inflammatory corticosteroid dexamethasone, were administered through enema and were found to release the drug only upon enzymatic digestion at inflamed tissue, says co-author Praveen Kumar Vemula from inStem. The team selected a material already approved by the FDA. They chose ascorbyl plamitate (AP), a negatively charged material that would automatically be attracted to positively charged sites of tissue damage, allowing the gel to anchor to these sites.The team then loaded the gel with a corticosteroid drug routinely used to treat IBD. They engineered the hydrogel so that it can be snipped by enzymes present only at the inflamed tissue site. When the enzyme comes in contact with it, the gel begins to disassemble, slowly releasing the medicine. The team tested the hydrogel’s abilities in two preclinical models of IBD and reported significant reduction in inflammation with less frequent doses as compared to traditional corticosteroid-containing enemas. “This technology will allow patients to take an enema once a week rather than every day and without systemic side effects or the need to retain the enema as the gel quickly attaches to ulcers, ultimately improving their quality of life," says co-corresponding author Jeff Karp, PhD, of the BWH Department of Medicine and a principal investigator at Harvard Stem Cell Institute.
1. Zhang, S. et al. An inflammation-targeting hydrogel for local drug delivery in inflammatory bowel disease. Science Transl. Med. 7, 300ra128 (2015) doi: 10.1126/scitranslmed.aaa5657