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2013 - 20172
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Subject: Veterinary Pathology × Author: SUVANEETH P × Start date: 2010 ×
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    ThesisItemOpen Access
    PORCINE DERIVED SCAFFOLD ASSISTED FULL THICKNESS SKIN WOUND HEALING IN RABBIT MODEL
    (COLLEGE OF VETERINARY AND ANIMAL SCIENCES MANNUTHY, THRISSUR, 2017-06-15) SUVANEETH P; SUVANEETH P; N. Divakaran Nair; N. Divakaran Nair
    The remodeling and regenerative responses of porcine cholecyst on full thickness skin wounds were evaluated in this study using rabbit as an animal model. Comparison of porcine cholecyst, porcine cholecyst seeded with autologous bone marrow cells and open wound control were made for evaluation. Porcine cholecyst was decellularized using a non-enzymatic, non-detergent based protocol and was checked for cellularity prior to in vivo evaluation. The in vivo evaluations were done on full thickness skin wound healing model in New Zealand White rabbits. The inflammatory, remodeling, and regenerative responses were evaluated 7, 14, 21 and 28 days post implantation. The H&E stained sections were evaluated for inflammatory and remodeling responses. Collagenization was evaluated and quantified using Masson’s trichrome and Picrosirius red staining. Differential collagenization was quantified using Herovici staining. Elastin deposition was ascertained using Verhoeff-Van Gieson’s staining. Proliferative response of the fibroblasts was evaluated by argyrophilic nucleolar organizer region (AgNOR) histochemistry and proliferating cell nuclear antigen (PCNA) immunostaining. Dermal cellular proliferation was quantified using PCNA immunohistochemistry. Re-epithelialization and epidermal formation was quantified using cytokeratin based immunohistochemistry. Vimentin immunohistochemistry was used to assess the mesenchymal cell response. ASMA immunohistochemistry was carried out to assess myofibroblast activity and CD 31 for neoangiogenesis. The results of the current study indicated that porcine derived cholecyst scaffolds are very well suited to be used as a bioscaffold material for full thickness skin wound healing, owing to their biochemical, biodegradable, biocompatible and tissue remodeling responses. The use of porcine cholecyst in full thickness skin wounds showed improved epithelialization and faster remodeling devoid of infections or graft rejections in all the animals under study. Scab formation, ulcerations, infections and other complications were also not observed in any of the scaffold assisted wounds. The scaffold enhanced cellular proliferation and keratinocyte activity. Controlled collagenization and faster replacement of immature collagen to mature collagen were also observed in scaffold assisted treatments. Improved neoangiogenesis were seen on scaffold assisted wounds from day seven itself which aided in faster healing of granulation tissue. Complete healing occurred around 14 days in graft assisted treatments, which was significantly early for the size of the wounds. Porcine cholecyst assisted healed wounds showed minimal wound contraction and reduced the chances of scar formation. The presence of autologous marrow cells enhanced proliferating cells, possibly due to the presence of bone marrow derived mesenchymal stem cells, as observed by a higher mesenchymal cell activity in vivo in marrow cells supplied scaffold. Use of autologous marrow cells has improved the time of healing in porcine cholecyst assisted skin wound healing, but not significantly from the application of a non-cell seeded matrix.
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    ThesisItemOpen Access
    COMPARATIVE HEALING RESPONSES OF DIFFERENTLY PROCESSED DECELLULARISED BOVINE PERICARDIUM IN RAT ABDOMINAL REGENERATION MODEL
    (COLLEGE OF VETERINARY AND ANIMAL SCIENCES-MANNUTHY,THRISSUR, 2013) SUVANEETH P
    The efficacy of two different protocols for the decellularisation of bovine pericardium for induced regeneration has been evaluated in this experiment. The pericardia were decellularised using a non-detergent based enzymatic protocol and a biodetergent (deoxycholic acid) based newer protocol, and was evaluated in vitro and in vivo for comparison. The in vitro characterisation was done using tensile testing, contact angle measurement and collagenase susceptibility. The in vivo implantation studies were carried out in full wall abdominal defect model in Sprague-Dawley rats. The inflammatory, immune and regenerative responses were evaluated 15, 30 and 90 days post implantation. The H&E stained sections were evaluated semi-quantitatively for the cellular and tissue responses of inflammation, collagenisation and regeneration of skeletal muscles. Skeletal muscle formation and collagenisation were further confirmed by Masson trichrome stain. The inflammatory response to the implants was chronic with mononuclear cell infiltration, characterised by lymphocytes, plasma cells and macrophages. The autograft significantly differed and found advantageous to the implants. The implants were largely accepted by all the experimental animals as shown by increased neovascularisation, fibroblast proliferation, collagen deposition and striated muscle formation. Collagen deposition in the implants was found to be of similar extend which was analysed using image analysis. The results of the study showed that bovine pericardium decellularised with deoxycholic acid treatment and bovine pericardium decellularised using nondetergent based enzymatic process elicited comparable inflammatory and good regeneration responses and there were no differences in the responses of decellularised pericardium produced by two different protocols and both the materials were found to be equally effective in inducing regeneration.