<p>Includes Bibliographical references (leaves 83- 94).Forty-three male athymic nude mice were implanted with human vaginal mucosal cysts under general anaesthesia with Ketamine [25mg/kg] and Medetomidine [0.5mg/kg]. Cysts in 37 mice were recovered after 9 weeks of growth. twenty three cyst linings had retained the original structure of the vaginal epithelium. No marked deifference was present between the thickness of 9 week old linings and donor vaginal epithelium. The contaminants isolated from the skin of mice before implantation were mainly normal commercals of healthy experimental animals. There was no distinct difference in the number of cases with intact cyst formation between the terramycin/vitamin cocktaik group. The frequency of poor wound healing and/ or murine epidermis ingrowth was three times higher in animals stitched with silk sutures that in those cases where nylon sutures were used.</p>

<p>Includes Bibliographical references (leaves 83- 94).Forty-three male athymic nude mice were implanted with human vaginal mucosal cysts under general anaesthesia with Ketamine [25mg/kg] and Medetomidine [0.5mg/kg]. Cysts in 37 mice were recovered after 9 weeks of growth. twenty three cyst linings had retained the original structure of the vaginal epithelium. No marked deifference was present between the thickness of 9 week old linings and donor vaginal epithelium. The contaminants isolated from the skin of mice before implantation were mainly normal commercals of healthy experimental animals. There was no distinct difference in the number of cases with intact cyst formation between the terramycin/vitamin cocktaik group. The frequency of poor wound healing and/ or murine epidermis ingrowth was three times higher in animals stitched with silk sutures that in those cases where nylon sutures were used.</p>

Magister Scientiae Dentium - MSc(Dent) / Includes Bibliographical references (leaves 83- 94).Forty-three male athymic nude mice were implanted with human vaginal mucosal cysts under general anaesthesia with Ketamine [25mg/kg] and Medetomidine [0.5mg/kg]. Cysts in 37 mice were recovered after 9 weeks of growth. twenty three cyst linings had retained the original structure of the vaginal epithelium. No marked deifference was present between the thickness of 9 week old linings and donor vaginal epithelium. The contaminants isolated from the skin of mice before implantation were mainly normal commercals of healthy experimental animals. There was no distinct difference in the number of cases with intact cyst formation between the terramycin/vitamin cocktaik group. The frequency of poor wound healing and/ or murine epidermis ingrowth was three times higher in animals stitched with silk sutures that in those cases where nylon sutures were used. / South Africa

Thesis (Ph.D)--Biomedical Engineering, Georgia Institute of Technology, 2009. / Committee Chair: Bellamkonda, Ravi; Committee Member: Babensee, Julia; Committee Member: Butera, Robert; Committee Member: DeWeerth, Steve; Committee Member: Lee, Robert; Committee Member: McKeon, Robert. Part of the SMARTech Electronic Thesis and Dissertation Collection.

Staphylococcus schleiferi, Staphylococcus lugdunensis, and Staphylococcus epidermidis produce a high incidence of abscesses in a mouse model with an implanted foreign body. We investigated the significance of the foreign body in this process. Fourteen strains of S. schleiferi, S. epidermidis, and S. lugdunensis were tested in our model. A preadhered foreign body was implanted into one mouse group, followed by injection of a test strain. Another group received injection without implant. Abscesses were assessed at 7 days; foreign bodies and infected tissues were cultured. The percent of samples that developed abscesses or were culture positive was compared for each strain. Nearly all mice infected with S. schleiferi developed abscesses and were culture positive. The foreign body made no difference in abscess formation for three of four S. schleiferi but increased the incidence of both organism recovery and abscess for three of five S. epidermidis. The foreign body enhanced abscess formation for four of five S. lugdunensis, with all five strains yielding significantly more culture recovery. Although the pathogenicity of nine strains was increased by the foreign body, five strains yielded high abscess and culture recovery rates that were not enhanced by its presence.

No description available.

Thesis (118-130)--University of Washington, 2007. / Vita. Includes bibliographical references (leaves 118-130).

No description available.

Cochlear implants (CIs) help to restore basic auditory function in patients who are deaf or have profound hearing loss. However, CI patients suffer from limited voice and tonal perception due to spatial separation between the stimulating CI electrode and the receptor spiral ganglion neurons (SGNs). Directed regeneration of proximate SGN axons may improve tonal performance and implant fidelity by decreasing the spatial separation between the CI electrode and the neural receptor. Additionally, fibrous scar tissue formation on the surface of implanted electrodes further decreases tonal perception through current attenuation and spreading resulting in late-term hearing loss. Thus, designing surfaces that induce favorable responses from neural tissues will be necessary in overcoming signal resolution barriers. In this work, the inherent spatial and temporal control of photopolymerization was used to functionalize surfaces with topographical and biochemical micropatterns that control the outgrowth of neural and other cell types. First, laminin, a cell adhesion protein was patterned using a photodeactivation process onto methacrylate polymer surfaces and was shown to direct the growth of spiral ganglion neurons (SGN), the primary auditory neural receptors. These protein patterns could even overcome low amplitude/high periodicity competing topographical cues. Additionally, glass substrates were patterned with linear zwitterionic polymers and fibroblasts, astrocytes, and Schwann cells all showed dramatically decreased cell adhesion on 100 µm precocity patterns. Further, SGN neurites showed excellent alignment to these same patterns. Next, poly(dimethyl siloxane) (PDMS) was coated with a crosslinked zwitterionic thin film using a single step photografting/photopolymerization process to covalently bind the hydrogel to PDMS. These coated surfaces showed dramatically lower levels of protein, cell, and bacterial adhesion. Finally, zwitterionic hydrogels were strengthened by changing the concentration of poly(ethylene glycol) diacrylate (PEGDA) and 2-hydroxyethyl methacrylate (HEMA) in the formulation. The direct relationship between changing zwitterionic hydrogel formulation to strengthen the hydrogel and the anti-fouling properties were established. The fundamental understanding and design of cochlear implant materials described herein serves as a foundation for the development of next generation neural prosthetics.

<p>The success of implanted medical devices, such as biosensors, is dependent on the immune reaction to the surface of the implanted material. This immune reaction, termed the foreign body reaction, is potentially affected by the physical and chemical properties of the implanted material. Macrophages interact with the surface of the implanted material and secrete intercellular signals, including cytokines and growth factors, which direct the actions of immune cells in the surrounding tissue. The type and quantity of cytokines and growth factors produced by macrophages at an implant surface could be an indicator of the outcome of the foreign body reaction. </p><p>This study investigated the effect of the surface chemistry of an implanted device on the production of cytokines and growth factors. First, microdialysis sampling was characterized as a technique for collecting cytokines and growth factors from the tissue surrounding an implant. Based on this characterization, it was determined that a direct sampling method would be more suitable than microdialysis sampling for determining accurate tissue concentrations of cytokines and growth factors. Second, an in vitro model was developed and utilized to assess cytokine and growth factor production from monocyte/macrophage cultures seeded onto commonly implanted polymeric biomaterials with varying surface chemistries. The materials included in this study were polyethylene (PE), polyurethane (PU), polymethyl methacrylate (PMMA), expanded polytetrafluoroethylene (ePTFE), and a cytotoxic organo-tin polyvinyl chloride (ot-PVC) as a positive control. From this in vitro model, it was determined that the varying surface chemistries of these non-toxic materials, excluding ot-PVC, did not significantly affect the types and quantities of cytokines and growth factors produced. Finally, an in vivo model for evaluating the cytokine and growth factor response to an implanted biomaterial was utilized for comparison with the in vitro findings. In this model, biomaterials were implanted subcutaneously within the lumen of a stainless steel mesh cage. The mesh cage served to create a "pocket" where wound exudate fluid collected within the cage, surrounding the implanted biomaterial. The materials included in this study were PE, PU, and ot-PVC. Cytokines and growth factors produced at the material surface were sampled directly from the exudate fluid. The results from this in vivo study indicate that cytokine and growth factor production were not significantly impacted by the varying surface chemistries of the implanted biomaterials. The in vivo data support the findings from the in vitro model, suggesting that the foreign body reaction proceeds in a similar fashion for each of these non-cytotoxic, polymeric biomaterials with varying surface chemistries.</p> / Dissertation