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Research Highlight - Stable analog of insulin needs no refrigeration

The need to refrigerate certain temperature-sensitive vaccines and drugs, insulin in particular, is a major challenge for people living in tropical and subtropical regions of the developing world.

A major health challenge for people living in tropical and subtropical regions of the developing world is the “cold chain,” the need to refrigerate certain vaccines and drugs, particularly insulin. It’s a nearly impossible-to-fill requirement in poor, technology-starved countries.

But a solution is on the horizon. With members of his laboratory, Dr. Michael Weiss has invented a new type of insulin that is ultra-stable and fully active for many months, even at temperatures above 100o F.

Diabetic Africans without access to refrigeration or air conditioning are unable to keep their insulin at or below what would be room temperature in an affluent household. They resort to burying their insulin in the ground to protect it from the heat of the day. “The thermometer in villages and towns can soar to 120◦ F, causing the potency and shelf life of insulin and other medications to break down,” explains Dr. Weiss “With each degree the temperature rises, the rate of insulin’s degradation goes up.” “At above-room temperature, insulin can get tangled,” Weiss explains. The tangled insulin, called amyloid, has no activity and can cause painful reactions when injected.

“We were able to change the molecular design of insulin to allow us to produce a new kind of clear, stable analog that has the desired properties of regular insulin but does not degrade, even at extremely high temperatures,” he says. “This new insulin can maintain its clarity and biological function for six months at tropical temperatures.”

This breakthrough insulin research could not come at a better time. The current need for stable insulin has increased in the last years. “Many Africans as well as patients in the Middle East and Asia are now substituting parts of their traditional diet for a Western, diabetes-producing diet, rich in refined white sugars and saturated fats,” explains Weiss. Not surprisingly, perhaps, with the developing world’s limited access to stable insulin, almost 80% of deaths from diabetes occur there. “The present epidemic of diabetes is a global problem.”

The discovery of an ultra-stable insulin will not only benefit Third World countries. “When there is a natural disaster anywhere in the world, like Hurricane Katrina, there is a critical need for a supply of medicines that do not require refrigeration,” Weiss says. “Organizations like FEMA (Federal Emergency Management Agency, WHO (World Health Organization), and the American Red Cross could easily use and store this insulin.”

There is also potential of using the ultra-stable insulin in insulin pumps placed inside a diabetic’s abdomen. “Instead of taking shots three to four times a day, with this new technology, a person with diabetes could push a button on a hand-held remote control to “beam” the ultra-stable insulin in his or her internal pump reservoir right into the blood stream. This cannot be done now because body temperature (98.6o F) is too high for insulin to remain untangled inside the reservoir.”

The discovery of the thermostable insulin was described in a cover article in the Journal of Biological Chemistry.

Adapted from a Cleveland Jewish News Article

 

analog of insulin structure

Structure of insulin and thermostable insulin