The aim of this study was to investigate the effects of various polysaccharides and their breakdown products on the proliferation and migration of cells involved in wound healing, both in vitro and in vivo, with the ultimate aim of developing a commercially viable collagen dressing containing an active polysaccharide fragment which would stimulate the wound healing response to such a degree that good quality and significantly faster healing would take place. Hyaluronic acid (HA), chondroitin sulphate (CS), heparin, Oxidised Regenerated Cellulose (ORC) and pectin were tested in this study. Some HA fragments and CS fragments significantly stimulated (p<O.05) the proliferation of Bovine Aortic Endothelial (BAEC) cells, although other HA or CS fragments were without effect. All HA and CS fragments tested also had no effect on the migration of L929 cells in the Boyden Chamber assay. Pectin stimulated the proliferation and migration of L929 cells, whereas, ORC 1 and heparin both suppressed proliferation (25% - 45% inhibition) of these cells but stimulated their migration. When injected subcutaneously into Polyvinyl alcohol sponges in the rat wound model at concentrations of 10 and 50J.1g/ml, heparin brought about an increased presence of granulation tissue in the wound after 10 days and 7 days respectively. These results indicate that structurally similar polysaccharides can have profoundly different effects on cell proliferation and migration, and thus have potential therapeutic use in guiding cell movement in wound healing.

The use of polysaccharides as building blocks in the development of drugs and contrast agents delivery systems is rapidly growing. This can be attributed to the outstanding virtues of polysaccharides such as biocompatibility, biodegradability, upgradability, multiple reacting groups and low cost. The focus of this thesis was to develop and characterize novel starch based hydrogels and nanoparticles for delivery of drugs and imaging agents. To this end, two different systems were developed. The first system includes polymer and nanoparticles prepared by graft polymerization of polymethacrylic acid and polysorbate 80 onto starch. This starch based platform nanotechnology was developed using the design principles based on the pathophysiology of breast cancer, with applications in both medical imaging and breast cancer chemotherapy. The nanoparticles exhibited a high degree of doxorubicin loading as well as sustained pH dependent release of the drug. The drug loaded nanoparticles were significantly more effective against multidrug resistant human breast cancer cells compared to free doxorubicin. Systemic administration of the starch based nanoparticles co-loaded with doxorubicin and a near infrared fluorescent probe allowed for non-invasive real time monitoring of the nanoparticles biodistribution, tumor accumulation, and clearance. Systemic administration of the clinically relevant doses of the drug loaded particles to a mouse model of breast cancer significantly enhanced therapeutic efficacy while minimizing side effects compared to free doxorubicin. A novel, starch based magnetic resonance imaging (MRI) contrast agent with good in vitro and in vivo tolerability was formulated which exhibited superior signal enhancement in tumor and vasculature. The second system is a co-polymeric hydrogel of starch and xanthan gum with adjustable swelling and permeation properties. The hydrogels exhibited excellent film forming capability, and appeared to be particularly useful in controlled delivery applications of larger molecular size compounds. The starch based hydrogels, polymers and nanoparticles developed in this work have shown great potentials for controlled drug delivery and biomedical imaging applications.

Thesis (Ph. D.)--University of Hong Kong, 2008. / Also available in print.

Thesis (M.S.)--University of Wisconsin--Madison, 1965. / eContent provider-neutral record in process. Description based on print version record. Includes bibliographical references.

Thesis (Ph. D.)--University of Delaware, 2008. / Principal faculty advisor: Darrin J. Pochan, Dept. of Materials Science & Engineering. Includes bibliographical references.

Thesis (Ph. D.)--University of Nevada, Reno, 1999. / Includes bibliographical references. Online version available on the World Wide Web.

Thesis (M.Med.Sc.)--University of Hong Kong, 2003. / Includes bibliographical references (leaves 43-51). Also available in print.

Thesis (M. Med. Sc.)--University of Hong Kong, 2004. / Also available in print.

Thesis (Ph. D.)--University of Wisconsin--Madison, 1969. / Typescript. Vita. Description based on print version record. Includes bibliographical references.

Thesis (M.S.)--West Virginia University, 2006. / Title from document title page. Document formatted into pages; contains vi, 45 p. : ill. (some col.). Includes abstract. Includes bibliographical references (p. 40-45).