Experimental Study On The Repair Of Radius Defect Of Rabbit With Vascularized Muscle Flap Combined With Bone Morphogenetic Protein Microspheres

Bone defect was one of the failed symptom in clinical, especially , the therapeutic efficacy of bone defect companion with severity soft tissue injury was very bad, so we must to find more effective therapy methods. The activity of bone morphogenetic protein has been confirmation by many experiments, but the clinical apply effect of BMP was not satisfaction till now. The mostly reason was in defect of perfect carrier system. The object of this experiment was resolved the problem in a certain extent degree, as follows:1 To prepare CSAMs wrapped with BMP and check the character of CSAMs and BMPMs.2. To fabricate the animal model using VMF and BMPMs in order to repair bone defect and to observe the effect of repair in bone defect with them in vivo.The experiment divided into two parts, at first, we have need to prepare bone morphogenetic protein microspheres and testing its properties. Chitosan and sodium alginate were fabricated into microspheres and wrapped with BMP, and the characteristic of microspheres was examined in vitro. BMSc Segregated from the bone marrow of New Zealand rabbit was cultured with BMPMs and CSAMs in vitro respectively. To comprehend the effect of BMPMs and CSAMs with regard to BMSc, Phase contrast microscope , MTT, coomassie brilliant blue and alkaline phosphatase activity were tested at third, sixth and ninth day.Secondly, fourty-eight forelimbs of twenty-four New Zealand rabbits were divided into four groups at random as follows: VMF/BMPMs/BMSc, VMF/BMPMs, VMF/BMP and VMF/CSAMs. 15 mm radius bone defect was made, and implanted with the denerved and vascularized muscle flap of flexordigitorum profundus. During the blunt dissection of muscle flap, its blood supply should be protected carefully. BMPMs, CSAMs and BMP were distributed in muscle flaps respectively, and cells group was combinated with BMSc additionally. The osteogenesis was investigated by gross examination, X-ray, histology, optical densit analysis and biomechanics at second, fourth, eighth week postoperative, thereby the repair of bone defect was evaluated with them. We have got many results as follows:1. The BMP microspheres have ideal form and well-distributed size, and its average diameter of the microspheres is 10.2um. The average rate of embedding of the BMP is 69.14%.2. There was no obvious abnormality in cellular form between BMPMs and BMSc Compounded with CSAMs. The quantity of cells increased following by the elongation of time of culture. CSAMs has no distinct effect to cellular proliferation or secretion, but BMPMs had significant auxo-action to cellular Synthesis of protein and expression of ALP.3. VMF combined with BMPMs have recovered 15 mm radius bone defect of rabbits.4. There was no difference between VMF/BMPMs/BMSc and YMF/BMPMs in repair of the bone defect of rabbit's radius, but both of them excelled VMF/BMP and VMF/CSAMs.We have draw some conclusions as follows:1. BMP microspheres possess satisfactory biocompatibility and function of the reinforcing osteogenesis of BMSc in vitro.2. There was no obviously difference in the repair of bone defect between VMF/ BMPMs with bone marrow stem cell and VMF/ BMPMs without bone marrow stem cell, but both of them excelled VMF/BMP and VMF/CSAMs.