Thesis (Ph. D.)--University of Wisconsin--Madison, 1943. / Typescript. Vita. eContent provider-neutral record in process. Description based on print version record. Includes bibliographical references (leaves [65]-71).

Thesis (M.S.)--University of Wisconsin--Madison, 1947. / Typescript. eContent provider-neutral record in process. Description based on print version record. Includes bibliographical references (leaves 52-60).

Thesis (doctoral)--University of Lund.

Thesis (doctoral)--University of Lund.

Thesis (Ph.D.) - University of Queensland, 2006. / Includes bibliography.

Hyaluronic acid plays an important role in regulating the transport of fluid and solutes in the interstitium. The concentration and molecular weight of hyaluronic acid in different connective tissues are different. These factors influence the hydraulic flow conductivity, K', of connective tissues. An experimental study of the effect of concentration and molecular weight of hyaluronic acid on the hydraulic flow conductivity is the subject of this work. Hyaluronic acid of different molecular weights were obtained by fractionating commercially available hyaluronic acid using ion-exchange column chromatography. The results were not reproducible, partly because of the elution process was not continuous. Nevertheless, three molecular weight fractions (6.99 to 11.1 X 10⁵ ) were obtained. Hyaluronic acid of lower molecular weights (0.454 to 1.65 X 10⁵) were obtained by acid hydrolysing some of the chromatographed fractions for 15 min., 1 hour and 2 hours. A more homogeneous hyaluronic acid fraction (M.W. = 1.96 X10⁵) was obtained by fractionating hyaluronic acid materials acid hydrolysed for 15 min. The hydraulic flow conductivity of solutions of hyaluronic acid can be calculated from the sedimentation coefficient of the solutions at 20°C, S₂₀‚ measured by ultracentrifugation. Centrifugation experiments determining the S₂₀ of the molecular weight fractions of hyaluronic acid at various concentrations were therefore undertaken. The results showed that S₂₀ decreased with increased concentration of hyaluronic acid. Also, the curves of as a function of hyaluronic acid concentration, c, converged at high concentration, indicating that a three dimensional molecular network is formed at high concentration and the extent of entanglement between molecules is the same for the high and low M.W. fractions. At lower concentrations, for the acid hydrolysed fractions, S₂₀ increased with M.W., which is in agreement with past sedimentation data. For the non-acid hydrolysed fractions, the difference in S₂₀ between two higher M.W. fractions is small, and the lowest M.W. fraction has consistently higher S₂₀ than the higher M.W. fractions. This finding does not agree with past literature results, and the difference in results is most probably due to experimental errors. However, when the fractionated non-acid hydrolysed fractions are taken as a high M.W. group (M.W. = 6.99 to 11.1X10⁵) and the acid hydrolysed fractions as a low M.W. group (M.W. = 0.454 to 1.96X10⁵), the curves of S₂₀ as a function of c of the low M.W. group fall below those of the high M.W. group, which is in agreement with past sedimentation data. The hydraulic conductivities (K'), calculated from S₂₀ data, for all the HA fractions varied inversely with concentration. The log-log plots of K' versus c compared well with the results of Ethier (1986). The K' versus c relationships for all the fractions converged at high concentrations. At low concentrations, the HA molecules of the high M.W. group has a higher K' than those of the low M.W. group. / Applied Science, Faculty of / Chemical and Biological Engineering, Department of / Graduate

Thesis (doctoral)--Lund University, 1994. / Added t.p. with thesis statement inserted.

Thesis (doctoral)--Lund University, 1994. / Added t.p. with thesis statement inserted.

No description available.

Postoperative adhesions form as the body's natural response to injury in an effort to temporarily protect and supply nutrients to these tissues. However, adhesions can remain permanent, and fail otherwise successful surgeries by tethering tissues together that are normally separated. An ideal anti-adhesive device reduces unwanted adhesions and leaves the patient in a state most similar to before surgery. This dissertation introduces a novel, robust hydrogel film consisting of two hydrophilic polydisaccharides, hyaluronic acid (HA) and alginate. To address the challenge of retaining HA in alginate-rich hydrogels, we methacrylated the HA (GMHA), creating hydrophobic moieties. These hydrophobic interactions shift the percolation threshold, allowing for greater concentrations of GMHA to be retained in resulting films. UV crosslinking retains GMHA beyond the percolation threshold and widens the possibilities of usable films. To enhance the mechanical properties of these alginate/GMHA films, we employed a previously developed method for creating thin, branched, interconnected fibers using urea crystal templating. Templated films are softer and, yet, tougher than films that have not been templated. This toughness is a result of increased density of polymer in the fibers. These films were selected as most conformable and most robust by surgeons in a blinded handling study. In a rat peritoneal abrasion model for adhesion formation, the films successfully prevented adhesions with statistical equivalence to the leading anti-adhesion device commercially available. Finally, future recommendations are suggested for the development of a bilayer construct with a collagen/alginate blend bound to an alginate/HA layer for an anti-adhesive and regenerative strategy. This construct addresses the need for opposing strategies in the dynamic environment of wound healing. Further research is needed to develop the usefulness of this bilayer system, as preventing unwanted adhesions is merely a first step in achieving a blemish-free healed wound. / text