Calcium polyphosphate (CPP) is a suitable substrate in a novel tissue-engineering strategy. The strategy aims to culture articular cartilage in vitro onto porous CPP and then implant the biphasic construct into the joint to replace damaged cartilage. CPP substrates should degrade faster to enhance repair. This project examined the structural and degradation effects of doping CPP with sodium phosphate, sodium hydroxide, and sodium carbonate. Doping concentration was narrowed to 0.01 Na2O/CaO for comparable phase composition to pure CPP. All doped groups sintered and crystallized at lower temperatures than pure CPP. Hydroxide-doped CPP did not form adequate sinter necks. At similar open porosity, Phosphate-doped CPP had similar diametral strength than pure CPP, while Carbonate-doped CPP had greater diametral strength. Degradation in vitro showed that Phosphate-doped CPP had greater strength loss, while Carbonate-doped CPP had similar strength loss, compared to pure CPP. Both doped groups degraded more slowly than pure CPP.

Calcium polyphosphate (CPP) is a suitable substrate in a novel tissue-engineering strategy. The strategy aims to culture articular cartilage in vitro onto porous CPP and then implant the biphasic construct into the joint to replace damaged cartilage. CPP substrates should degrade faster to enhance repair. This project examined the structural and degradation effects of doping CPP with sodium phosphate, sodium hydroxide, and sodium carbonate. Doping concentration was narrowed to 0.01 Na2O/CaO for comparable phase composition to pure CPP. All doped groups sintered and crystallized at lower temperatures than pure CPP. Hydroxide-doped CPP did not form adequate sinter necks. At similar open porosity, Phosphate-doped CPP had similar diametral strength than pure CPP, while Carbonate-doped CPP had greater diametral strength. Degradation in vitro showed that Phosphate-doped CPP had greater strength loss, while Carbonate-doped CPP had similar strength loss, compared to pure CPP. Both doped groups degraded more slowly than pure CPP.

Osteoarthritis is characterized by pain and inflammation in joints, typically weight-bearing joints such as the knee. An early warning sign of osteoarthritis is the loss of proteoglycan molecules in the cartilage matrix. A surrogate method for measuring proteoglycan loss is detection of sodium ions, which ionically bond to negatively charged glycosaminoglycan side chains. Sodium MRI has the potential to non-invasively measure proteoglycan content, and hence act as a diagnostic tool for osteoarthritis. However, as sodium MRI suffers from low sodium concentrations in vivo and reduced MR sensitivity compared to standard proton MRI, techniques are required which optimize signal. This thesis examines the hardware, software, and acquisition techniques required in order to achieve high resolution, excellent quality sodium MR images of the human knee in vivo, which has potential applications in early diagnosis as well as pharmacological treatment evaluations of osteoarthritis.

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Thesis (Ph. D.)--University of Hawaii at Manoa, 1990. / Includes bibliographical references (leaves 135-153) / Microfiche. / xi, 153 leaves, bound ill. 29 cm

Thesis (Ph. D.)--State University of New York at Binghamton, Chemistry Department, 2007. / Includes bibliographical references.

Thesis (Ph.D.)--Michigan State University. Dept. of Pharmacology and Toxicology, 2008. / Title from PDF t.p. (viewed on Mar. 30, 2009) Includes bibliographical references (p.177-201). Also issued in print.

Thèse (M.Sc.)--Université Laval, 2008. / Bibliogr.: f. 61-63. Publié aussi en version électronique dans la Collection Mémoires et thèses électroniques.

Thesis (Ph. D.)--University of Michigan, 1939. / Cover title. "Reprinted from the Physical review, vol. 56, no. 2, July 15, 1939." Includes bibliographical references.

Thesis (Ph. D.)--University of Chicago, 1940. / Reproduced from type-written copy. "Private edition, distributed by the University of Chicago libraries, Chicago, Illinois." Includes bibliographical references.