5th July 2012
Atherosclerosis is nothing less than a global epidemic. The condition leads to arthersclerotic cardiovascular disease, which is the cause of more than 50 million deaths around the world. Atherosclerosis itself occurs when fat, cholesterol, calcium, and other substances deposit on arterial walls to form plaque.
To treat the disease, Maryam Mobed Miremadi, PhD, a bioengineering professor at San Jose State University and Srikanth Darbha, a graduate student at the university, sought to come up with a natural way to dissolving plaque by targeting cholesterol. “In intermediate stage plaque, about 22% of the plaque is made up of cholesterol,” Darbha says. “So I decided to investigate enzymes and stumbled across cholesterol oxidase, which degrades cholesterol directly,” says Darbha.
Using microencapsulation technology, the researchers experimented with the use of bacteria that could serve as a continuous source of this enzyme to degrade intermediate-stage arterial plaque. “By way of a literature search, I ran into Rhodococcus Erythropolis,” Darbha says. The bacteria was immobilized in biodegradable alginate-based capsules and was shown to effectively degrade cholesterol in in vitro experiments conducted over the course of eight days. The average decrease in cholesterol concentration was 1.11 mg per day.
Darbha plans on doing further research on the technology to determine how it performs in vivo. If it continues to show promise, he says that the research could lead to the development of a biodegradable stent that uses this technology to degrade plaque over time. “You could eliminate the restenosis phenomenon and can also minimize the biocompatibility issues that you have with traditional stents,” Darbha says. In addition, it could avoid the side effects of drug-based therapies for treating the buildup of arterial plaque. “What’s exciting for me is that using it in the field is actually a possibility.”