Publication Date

Spring 2013

Degree Type


Degree Name

Master of Science (MS)


General Engineering


Bradley Stone


Atherosclerosis, Cardiovascular disease, Cholesterol, Cholesterol oxidase, Plaque, Rhodococcus erythropolis

Subject Areas

Biomedical engineering


Cardiovascular disease is the leading cause of death in the United States and isprimarily due to hypercholesterolemia. The novel approach of combatting atherosclerosis presented in this research entails delivery of microencapsulated Rhodococcus erythropolis immobilized in biodegradable alginate-based microcapsules and utilizing the bacterium's cholesterol oxidase enzyme pathway to degrade cholesterol from intermediate-stage arterial plaque. The bacterial growth medium was optimized using Taguchi design methods to enable growth characterizations hindered by biosurfactant by-product. Methodologies for extraction and quantification of biosurfactant and cholesterol were developed and conducted simultaneous to bacterial growth assessment. Bacteria were encapsulated using atomization (850±50 μm) and inkjet bioprinting (32±5 μm) to study the effects of cell density and capsule miniaturization on the rate of cholesterol degradation. The cholesterol degradation rate was determined to be independent of cell density, and capsule miniaturization led to a near 4-fold increase in cholesterol degradation, thus allowing for 61.8% cholesterol in an

intermediate-stage lesion to be degraded.