Heparin is routinely given to patients before certain types of surgery and prior to treatments such as kidney dialysis to prevent blood clots from forming. Clots that do not naturally dissolve can travel through the blood stream and end up in the brain, causing stroke or in the lungs resulting in a pulmonary embolism.

Heparin is produced naturally by most animals, including humans, but most heparin used today is derived from pig intestines. China has become a popular location for manufacturing heparin because it has a much larger pig population. It is somewhat inexpensive to produce, however, ensuring the safety of drugs manufactured overseas has been a challenge for the Food and Drug Administration (FDA). Just last year, more than 80 Americans died and hundreds more were sickened after they received injections of specific batches of heparin that were manufactured in China. That heparin was later found to have been contained with oversulfated chrondroitin sulfate (OSCS). As a result, researchers have been working to find safer alternatives to heparin.

Liu, whose Recomparin research was published online in the Proceedings of the National Academy of Sciences journal last November, says he is also looking into customizing heparin for other uses, such as a treatment for small-cell lung cancer.

SOURCE: Heparin Recall › Researcher awarded NIH grant for development of synthetic heparin

“Previously it was nearly impossible to change the nature of the heparin generated by the enzyme,” said Jian Liu, Ph.D., associate professor at the UNC Eshelman School of Pharmacy medicinal chemistry and natural products division. “The degree of difficulty was 10-plus. Now it’s more like a two or three, which opens the door to the possibility of improving on the natural product.”

The method involves modifying the enzyme heparan sulfate 2-O-sulfotransferase, which produces heparin in the human body in addition to other heparin-like molecules. By modifying 2-O-sulfotransferase, researchers will be able to create customized forms of synthetic heparin with different properties, according to the report.

Heparin is typically administered to most patients during surgery and before some treatments such as kidney dialysis to prevent blood clots from forming. Heparin is produced naturally by most animals, including humans, but most heparin available today is derived from pig intestines. China has become a popular location for manufacturing heparin because it has a much larger pig population.

However, heparin manufactured in China raised concerns earlier this year after batches from Baxter International’s China plant were found to have been contaminated. The investigation into heparin resulted after more than 80 Americans died and hundreds more were sickened after receiving doses of the tainted heparin. As a result, researchers have been working to find safer alternatives to heparin, including developing synthetic versions.

“The pig stuff has served us well for 50 years and is very inexpensive, but if we cannot control the supply chain, we cannot ensure the safety of the drug,” Liu said. “I am working for the day when synthetic heparin can be brewed in large laboratories at a low cost.”

Liu and her colleagues also are looking into customizing heparin for other uses, such as a treatment for small-cell lung cancer.

Liu’s research recently was published online in the journal Proceedings of the National Academy of Sciences.

SOURCE: Heparin Recall › Scientists on road to modifying, customizing human heparin