N. Divakaran NairN. Divakaran NairSUVANEETH PSUVANEETH P2023-01-192023-01-192017-06-152017-06-15https://krishikosh.egranth.ac.in/handle/1/5810192582Thesis Submitted in partial fulfillment of the requirement for the degree of Doctor of Philosophy in Veterinary PathologyThesis Submitted in partial fulfillment of the requirement for the degree of Doctor of Philosophy in Veterinary PathologyThe 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.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.EnglishThesis