Thesis (doctoral)--Lund University, 1997. / Added t.p. with thesis statement inserted.

Thesis (doctoral)--Lund University, 1997. / Added t.p. with thesis statement inserted.

Diss. (sammanfattning) Stockholm : Karol. inst. / Härtill 6 uppsatser.

Thesis (M.S.)--University of Wisconsin--Madison, 1982. / Typescript. eContent provider-neutral record in process. Description based on print version record. Includes bibliographical references (leaves 30-34).

archives@tulane.edu / Tendons transmit loads from muscle to bone. Tendon injuries result in degenerative changes, including increased inflammatory response and poor healing. Tendon mechanical function is dictated by the composition and organization of the underlying extracellular matrix. Damage to the tendon extracellular matrix results in permanent functional decline. Provisional matrix deposition, which occurs during early tendon healing, may be influenced by sex and age. The effects of sex and age in patellar tendon injuries as well as the mechanisms that impede total restoration and therefore tendon mechanics following injury are unknown. Therefore, there is need to determine the role of age and sex on early tendon matrix deposition. Thus, the objective of this study was to examine age- and sex-dependent early tendon healing. An established patellar tendon biopsy procedure was used to evaluate changes in mechanical properties at 3-, 7-, and 14-days post injury in male and female mice. Significant differences with respect to sex and injury were found in tendon linear region elastic modulus and percent relaxation for 120-day mature mice. Mechanical properties appeared to decrease with increasing age; however, statistics could not evaluate this decrease due to low sample sizes for the 270- and 540-day mice. Sex differences in mechanical properties may be due to prolonged inflammatory response in injured female mice. Such prolonged exposure may result in increased deposition of type III collagen and thus exhibit altered mechanical function. These results provide valuable information to improve tendinopathy treatment options and to develop finite element models of tendon healing to inform surgical outcomes. / 1 / Richard Urbanowski

Background: Prolonged recovery after tendon injury has given rise to the need for innovative therapy including tendon engineering and cell based therapies. The role of cells in grafted or engineered tendon is poorly understood. Clarifying the persistence of grafted tissue is fundamentally important to ensure that tissue engineering strategies are fit for clinical application. We have devised a murine model for tendon grafting that allows for cell tracking and the assessment of tendon integration and engineered construct integration. Materials and methods: We studied the macroscopic and microscopic architecture of the mouse Achilles tendon to investigate its properties as a study model. Using microsurgical techniques, transgenic tendon grafting procedures were then carried out between C57B/L6 wild type and GFP (Green Fluorescent Protein) mice Achilles tendon. The temporal and spatial fate of the cells in the graft was assessed using quantitative serial histology and immunohistochemistry with Three Dimensional reconstruction. Markers for proliferation, collagen synthesis, cell death and inflammatory infiltrate were used. The Achilles tendon model was also applied to test its applicability to investigate tissue engineered tendon constructs developed in vitro. Results: GFP positive graft cells were seen at Day 3 and Day 21 but disappeared by Day 90. At Day 21both graft cells and the cells of the recipient tendon showed intense collagen synthetic activity. At the same time both graft and host tendon cells began to show signs of apoptosis which continued till Day 90. Subcutaneous tissue and paratenon maintained a much higher level of cellularity, cell proliferation, collagen synthesis and apoptosis at all time. The interplay between cell activity and cell death appear to play central role in the integration of the tendon graft. The persistence of tissue engineered tendon constructs was far less than syngenic or autografts. The Achilles tendon model proved to be a robust and economically viable model for testing of biomaterials particularly at the early stage of their development. Conclusion: The cells of tendon grafts persist only for a finite time before being repopulated by host cells. Tissue engineered cell-based constructs do not provide sufficient persistence to substitute in place of syngenic or autologous graft options. Future designs of engineered tendon should facilitate tendon integration and aim to persist for longer periods of time in order to participate in the healing process.

Tendons transfer forces from muscle to bone and allow the locomotion of the body. However, tendons, especially for tendons in the hand, get lacerated commonly in different injuries and the healing of tendon within the narrow channel in the hand will normally lead to tendon adhesion and sacrificed tendon mechanics. Researches have been focused on addressing tendon adhesion prevention but neglecting healed tendon mechanics. This thesis discusses the principles and challenges in the design of biomaterials regarding flexor tendon repair with advanced polymer chemistry and materials science. A rational platform, not only focusing on the prevention of tendon adhesion, but devoting more efforts on final healed properties of tendons via implementing glycopolymer-based materials to guide tendon cells attachment, was designed, fabricated and characterized. Controlled ring opening polymerizations and atom transfer radical polymerizations were combined for the synthesis of miktoarm well-defined block copolymers. Para-fluorine click reactions were then implemented to afford glycopolymers with glucose units. Obtained copolymers were transformed into 3D membranes constituting a porous fibrous structure utilizing electrospinning. The aligned structure was then fabricated to optimize the mechanics of these materials for practical application as well as reconstruct normal tendon physiological structure. Lastly, the toxicity, cell affinity and cell activity of obtained materials were evaluated in vitro employing tendon cells as a cell line to confirm the suitability of obtained platforms for flexor tendon repair.

Thesis (M.S.M.E.)--University of Delaware, 2008. / Principal faculty advisors: Thomas S. Buchanan and Kurt T. Manal, Dept. of Mechanical Engineering. Includes bibliographical references.

No description available.

Thesis (M.S.)--Boston University / PLEASE NOTE: Boston University Libraries did not receive an Authorization To Manage form for this thesis or dissertation. It is therefore not openly accessible, though it may be available by request. If you are the author or principal advisor of this work and would like to request open access for it, please contact us at open-help@bu.edu. Thank you. / 2031-01-01