Regenerativni potencijal masnog tkiva u nadoknadi defekata kostiju na eksperimentalnom modelu kalvarije kunića

Repair of bone defects that arise as a result of trauma, tumor resection, or congenital anomalies is still a big challenge for surgeons. More recently, tissue engineering (TE) based on the use of mesenchymal stem cells (MSCs) is an approach that seems promising in the regeneration of bone. Particularly rich source of MSCs is adipose tissue. Current approach of using mesenchymal stem cells from adipose tissue (ADSCs) and stem cells in general, in the tissue engineering and regenerative purposes is characterized by the expansion of these cells in vitro, and then planting of cells on carriers and their implantation. Since it has been shown that an environment rich in hydroxyapatite, as well as a natural bone, can be a good microenvironment for differentiation of ADSC into osteoblasts it was assumed that those cells in such an environment in the body can provide conditions for the differentiation into osteogenic cells. The aim of this study was to investigate the role of adipose tissue in regeneration of bone defects in the rabbit calvaria defect model in two ways, by isolating mesenchymal stem cell fraction and application without precultivation in vitro, and the application of whole adipose tissue cut into small pieces. Also the aim was to examine the role of commercial bone deputy (Bio-Oss) and nanomaterial CP-PLGA (calcium phosphate-poly-DL-lactide-co-glycolide) in the function of different cell carriers and tissues. The research included twenty experimental animals separated into four groups of five animals in each. In the first and the third group Bio-Oss (bovine bone mineral matrix) was used as a carrier of isolated cells and in the second and the fourth group nanomaterial CPPLGA was used as a carrier. On calvaria of each rabbit five defects were made from which four were filled with prepared grafts and implants and the fifth defect remained unfilled and represented a spontaneous regeneration. The process of creating bone tissue and bone density in defects were observed radiographically using MSCT-64 scanner after I, III and VI week of filling defects. Half of the animals (group I and II) were sacrificed after four weeks, and the rest (group III and IV) after eight weeks of filling defects. It was found that the degree of osteogenic process in the tested grafts depends on the type of biomaterial used as a carrier of cells and tissues, as well as biological components that are combined with it. The use of Bio-Oss in the role of the implant eventually leads to the 131 collapse of bone density. If Bio-Oss is used as a carrier in the grafts whose components are fat or whole blood then contributes significantly to the increasing and maintaining bone density. Nanomaterial CP / PLGA proved to be a good carrier for adipose-derived mesenchymal stem cells in regeneration of calvaria. The use of nanomaterials increases bone density only when used as a carrier for the ADSC. Combining fresh non-induced ADSC with nanomaterials in blood clots leading to rapid initiation of bone regeneration. Approach to assisted osteoregeneration which is based on the use of fresh non-induced ADSC has proven to be promising due to the favorable effect on bone regeneration and their simplicity. For the final application of ADSC and adipose tissue in regenerative purposes requires further research in order to improve these processes and optimize the