Study Of Treating Bone Necrosis With Vascularized Tissue Engineering Bone Constructed In Biological Reactor With Platelet Rich Plasma

Avascular necrosis of the femoral head is a major problem for orthopaedic surgeons, there is no way to cure. The basic problem of bone necrotic zone is the deficiency of osteoblast progenitor cells and vascular. Vascularization in necrotic area can increase the rate of bone tissue repair. Platelet-rich plasma(PRP) is autologous platelet concentrates after centrifugating the fresh whole blood, which contains growth factors and bioactive proteins,including platelet derived growth factor(PDGF),transforming growth factor(TGF-β),insulin-like growth factor(IGF),epidermal growth factor(EGF)and vascular endothelial growth factor(VEGF). PRP can enhance the tissue repair, vascularization and bone formation. This project aims to building high-quality vascularized tissue-engineered bone complex, cocultured three-dimensional dynamically bone marrow stromal cells (BMSCs) and beta three calcium of phosphoric acid ((3-TCP) in perfusion bioreactor, using the effect of angiogenesis and bone repair of PRP. Under the guidance of MRI, copying the rabbit model of necrosis of femoral head using cryoablation, the vascularized tissue-engineered bone complex is precisely plugged into the necrotic area of the femoral head through the argon helium cryoablatio probe tract. Gross observation, bone density measurement, MRI test, histological evaluation is used to observe bone repair in necrotic area, expecting to find a new breakthrough for the clinical treatment of early avascular necrosis of femoral head.1A novel animal model of osteonecrosis of the femoral head induced using a magnetic resonance imaging-guided argon-helium cryotherapy systemAbstract The aim of the present study was to establish a novel animal model of osteonecrosis of the femoral head (ONFH) using a magnetic resonance imaging (MRI)-guided argon-helium cryotherapy system. A total of48rabbits were used to generate the ONFH models. In group Ⅰ, the left femoral head of the rabbits received two cycles of argon-helium freezing-thawing under MRI guidance, while in group Ⅱ, the right femoral head of each rabbit received only one cycle of argon-helium freezing-thawing. X-ray, roentgenographic and histological examinations were performed. The percentages of lacunae in the femoral heads of group Ⅰ at weeks4,8and12following surgery (49.75±3.17,62.06±4.12and48.25±2.76%, respectively) were higher than those in group Ⅱ (39.13±4.48,50.69±3.84and37.50±3.86%, respectively). In addition, the percentage of empty lacunae in group Ⅰ was62.06%at week8following surgery. Therefore, an animal model of ONFH was successfully established using an argon-helium cryotherapy system. The percentage of empty lacunae in group Ⅰ was higher than that in group Ⅱ at weeks4,8and12after surgery.2Construction of tissue engineered bone by using bioreactor and platelet-rich plasmaAbstract This study is to construct tissue engineered bone by using bioreactor and platelet-rich plasma (PRP). Bone marrow mesenchymal stem cells (BMSCs) and β-tricalcium phosphate (β-TCP) were cultured in perfusion bioreactor and in PRP containing medium for21days to form BMSC-TCP composite. Rabbits were implanted with BMSC-TCP composite. Morphology of implanted BMSC-TCP composite was observed by scanning electron microscope and HE staining. Expression of CD31and VWF in implanted BMSC-TCP composite was detected by immunohistochemistry. After culturing in perfusion bioreactor and PRP, BMSCs were adhered on the β-TCP scaffold and the secretion of extracellular matrix was also seen. The stretching and proliferation of cells was good on the scaffold. Vascular endothelial cell markers of CD31and VEF were positively expressed. Tissue engineered bone can be constructed by using bioreactor and PRP. PRP, which contains multiple growth factors, may promote vascularization of tissue engineered bone. 3Repair of bone necrosis with vascularized tissue-engineered bone coculured in bioreactor using platelet-rich plasmaAbstract The aim of this study is to explore the effect of repair of bone necrosis with vascularized tissue-engineered bone coculured in bioreactor using platelet-rich plasma. A total of30New Zealand adult rabbits (3.0±0.3Kg) were used to generate the ONFH models using this way described in Experiment1.Both femoral heads of these rabbits received two circles of two cycles of argon-helium freezing-thawing under MRI guidance. Vascularize tissue-engineered bone cocultured in bioreactor using platelet-rich plasma using the way described in Experiment2. Thirty rabbits were randomly divided into groups A, B, C, D,E and F (5rabbits for each group). The defects were then repaired with various materials in the different groups:Group A with nothing, Group B withβ-TCP scaffold, Group C with MSCs-β-TCP composites, Group D with MSCs-β-TCP composites cocultured in bioreatctor, Group E with MSCs-β-TCP composites cocultured using PRP, and Group F with MSCs-β-TCP composites cocultured in bioreactor using PRP. All the rabbits were raised separately postoperatively. The rabbits were sacrificed and all femoral heads were evaluated with X-ray at twelve weeks postoperatively. The new bone formation area was evaluated from three slides of each specimen through the HPIAS-1000image analysis system and light microscopy. The percentage of new bone formation was calculated by the following formula:area of new bone÷area of observation×100%.In Group F, The ability of tissue engineered bone to repair the osteonecrosis was close to that of cancellous bone autograft. And there was no femoral head collapse. The new animal model of ONFH could be induced by argon-helium cryotherapy system, and the tissue engineering technique will provide an effective treatment.