Tiny drug-delivering capsules could sustain transplanted insulin-producing cells.
Researchers have long been exploring ways to transplant pancreatic islets to treat type I diabetes long term, eliminating the need for continual glucose monitoring and insulin injections. However, there are a number of challenges to this approach. Now, a study from researchers at the University of Illinois demonstrates in vitro that insulin-secreting cells, called islets, show increased viability and function after spending 21 days inside tiny capsules containing even tinier capsules bearing a drug which makes the cells more resilient to oxygen deprivation. The team state that their drug-carrying microsphere within a cell-bearing microcapsule could be the key to transplanting insulin-secreting pig pancreas cells into human patients whose own cells have been destroyed by type I diabetes. The study is published in the journal Drug Delivery and Translational Research.
Previous studies show that there are many hurdles to pancreatic islet transplantaton, viable islets that are also functional are needed so that they secrete insulin when exposed to glucose. Also, once islets are isolated from tissue, the next big challenge is to keep them alive and functioning after transplantation. The current study develops islets co-encapsulated with the exenatide-loaded microspheres which exhibit improved survival and glucose-stimulated insulin secretion, compared to those without.
The current study develops tiny microspheres which are loaded with a drug that improves cell viability and that function in hypoxic conditions. The microspheres are designed to provide an extended release of the drug over 21 days. The group packaged pig islets and the microspheres together within microcapsules, and compared them with encapsulated islets that didn’t have the drug-containing microspheres over three weeks.
Results show that after 21 days, around 71% of the islets packaged with the drug-releasing microspheres remained viable, while only about 45% of the islets encapsulated on their own survived. Data findings show that the cells with the microspheres also maintained their ability to produce insulin in response to glucose at a significantly higher level than those without the microspheres.
The team state their study demonstrates the viability in vitro of exenatide-loaded microspheres, exhibiting a sustained release over 21 days, co-encapsulated with porcine islets in alginate microcapsules. For the future, the researchers hope to test their microsphere-within-a-microcapsule technique in small animals before looking toward larger animal or human trials.
Source: University of Illinois