Date of Award

5-2015

Document Type

Thesis

Degree Name

Master of Science (MS)

Legacy Department

Bioengineering

Committee Member

Dr. Delphine Dean

Committee Member

Dr. Martine LaBerge

Committee Member

Dr. O. Thompson Mefford

Abstract

The use of vascular stents to treat occluded blood vessels is common practice; however, this procedure is often complicated by neointimal hyperplasia reocclusion and thrombogenesis. One treatment option is systematically administering heparin to activate antithrombin III leading to deactivation of thrombin and other proteases involved in blood clotting. This treatment is associated with high rates of bleeding and other vascular complications. In addition to the widely known anti-coagulation effects, heparin has long been known to exhibit an anti-proliferative effect on the growth of cells. The ideal solution would be localized delivery to the site of the interest. Recently, the advancements in magnetic resonance have allowed magnetic nanoparticles to be localized at sites of interest. We propose that a heparin-coated magnetite nanoparticle will fit this ideal solution given it's potential to deliver localized anti-coagulation and anti- proliferative effects. In this study, we present the synthesis, characterization, and initial cytotoxicity studies of such a particle. Magnetite nanoparticles were synthesized and characterized to determine magnetic core diameter, hydrodynamic diameter, zeta potential, and heparin loading. Live/Dead and MTS assays were utilized to assess cellular toxicity on vascular smooth muscle cells (VSMCs). Cellular uptake and actin distribution of VSMCs post nanoparticle treatment was observed with Prussian Blue Staining and immunofluorescence respectively. Nanoparticles were characterized by TEM to be in the middle of our target range with a diameter of 24.3nm. Heparin loading was found to range from 0.976 to 2.8896 ug heparin/ug nanoparticle depending on the synthesis batch. Proliferation and cytotoxicity studies on vascular smooth muscle cells showed that at the low loading of heparin on nanoparticles, there is indication of proliferation inhibition without VSMC cell death. There was not a noticeable cellular uptake of heparin nanoparticles; however, actin distribution gives possible indication that VSMCs were induced into their contractile phenotype. The results from this study demonstrate a successful synthesis route of heparin-coated nanoparticles and indications for further investigation of VSMC response.

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