Insulin-producing islet cells make up only one to two percent of the pancreas and are scattered throughout the organ.
They are surrounded by a network of connective tissue called the extra-cellular matrix (ECM). This dynamic complex of molecules is a key component of the islet microenvironment, and affects the development, survival and regenerative potential of the cells.
During the isolation process, the ECM is broken down and the islets lose their natural “home.” This state, known as anoikis -- from the Greek word for “homelessness” -- can also trigger cell death.
DRI researchers are trying to recreate the natural ECM by developing bioengineered scaffolds. These scaffolds provide physical support, deliver the necessary oxygen and nutrients, and keep the cells spatially distributed to mimic the native pancreas.
'Oxygen Sandwich'
Recognizing that islets require a high amount of oxygen for optimal health, the DRI’s Tissue Engineering and Stem Cell Development teams have created a new cell culture device called the “oxygen sandwich.”
This device provides the cells with a more natural oxygen environment than traditional culture methods.
In its study, the DRI team was able to significantly enhance beta cell development from pancreatic precursors and observe dramatic increases in insulin levels, as well as in many critical pancreatic genes.
These results, presented at the 2006 World Transplant Congress in Boston, are the first comprehensive analysis of the influence of oxygen levels on beta cell differentiation. This research opens the door to more efficient protocols for the differentiation of embryonic stem cells into beta cells.