Three samples of the biopolymer hyaluronic acid (HA) were characterized in the
following manner: the molecular weights were obtained via multi-angle laser light
scattering; the intrinsic viscosities were calculated through dilute solution
viscometry, and the rheology of HA solutions was determined with constant rate
rotational viscometry and dynamical mechanical testing.
In addition, the highly debated role of hyaluronic acid in wound healing was
examined by studying the effect that HA has upon thrombin-catalyzed fibrin
clotting. Fibrin, in phosphate-buffered saline, was clotted both alone and after
being incubated with HA. It was determined that the presence of hyaluronic acid
resulted in a slower clotting process; in effect, HA acts as an anti-coagulant. Based
upon the experimental evidence, it is proposed that this anti-coagulant phenomenon
arises through a combination of two mechanisms: 1) specific binding between HA
and fibrin, which acts to retard fibrin clotting through steric hindrance, and 2) the
formation of an HA network which slows fibrin clotting by hindering free diffusion
of fibrin and thrombin.
Finally, creation of a synthetic replacement for synovial fluid was attempted using
xanthan gum and locust bean gum in phosphate-buffered saline. The phenomenon
of gum synergism was utilized in an effort to exert some degree of fine-tuning over
the final rheological properties of the solution. This also would provide the side
benefit of reducing the weight of gum required per unit volume. By mixing the
solutions at different temperatures, it was possible to exploit the tendency of
xanthan gum to uncoil at higher temperatures and therefore bind more strongly to
locust bean gum. However, it was determined that no combination of gum
concentrations and processing conditions resulted in a gum solution that adequately
mimicked the rheology of a hyaluronan solution. / Graduation date: 2003
| Identifer | oai:union.ndltd.org:ORGSU/oai:ir.library.oregonstate.edu:1957/31641 |
| Date | 17 May 2002 |
| Creators | Barrett, Brandon J. |
| Contributors | Rochefort, Willie E. |
| Source Sets | Oregon State University |
| Language | en_US |
| Detected Language | English |
| Type | Thesis/Dissertation |
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