Text

theses

ETD graduate

Chronic wounds are wounds that fail to go through the key stages of wound healing in a timely and orderly way. Previous research shows that chronic wounds could be a result of impaired blood flow to the wound, as seen in diabetic wounds and pressure ulcers. Around 6.5 million Americans are affected by chronic wounds and the US spends around 23 billion dollars on the treatment of these wounds each year. Current treatments are expensive, ineffective, and could have serious side effects. The use of growth factors is being increasingly investigated as a possible treatment for chronic wounds. However, the hostile environment in chronic wounds that contain a large number of proteases results in exogenous growth factors being quickly degraded within the wound environment. This limitation has prevented growth factors from becoming widely utilized as a treatment option.This work, therefore, shows the development and characterization of vascular endothelial growth factor fused with elastin-like polypeptide (VEGF-ELP) fusion proteins, which have been hypothesized to remain stable for longer durations in the wound environment by resisting degradation by proteases. The protein was developed as recombinant fusion protein nanoparticles using transformation into a bacterial system and a protein purification technique called Inverse Transition Cycling (ITC). Purity was assessed using techniques such as sodium dodecyl sulfate- polyacrylamide gel electrophoresis (SDS-PAGE) and western blotting. The physical characterization of VEGF-ELP was done using a turbidity test and particle size measurement on the purified final product. Several biological assays were also conducted in vitro to show that VEGF-ELP can enhance the different processes which play key roles in wound healing, such as cellular proliferation, migration, and angiogenesis. It was found that endothelial cells show increased proliferation and tube formation and that fibroblasts have better migratory characteristics in the presence of VEGF-ELP. Future steps could involve in vivo testing in experimental animal models with spinal cord injury and diabetes to demonstrate enhanced wound closure in the presence of VEGF-ELP.

ETD_11024

M.S.

Includes bibliographical references

doi:10.7282/t3-gav5-jy08

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