OBJECTIVE: To investigate the ability of repairing bone defect with the compound of coralline hydroxyapatite porous (CHAP), fibrin sealant(FS) and staphylococcus aureus injection (SAI), and the feasibility to use the compounds as bone substitute material. METHODS: The animal model of bone defect was made on the bilateral radius of 54 New Zealand white rabbits, which were randomly divided into the experimental group(the defect was repaired with CHAP-FS-SAI), control group(with autograft) and blank control group(the defect was left unrepaired) with 18 rabbits in each group. The ability of bone defect repair was evaluated by gross observation, histopathological study, X-ray and biomechanical analysis 2, 4, 8 and 12 weeks after repair. RESULTS: (1) In the 2nd week, tight fibro-connection could be found between the implant and fracture site and there were many fibroblasts and capillary proliferation with many chondrocytes around CHAP in the experimental group, while only a few callus formed, and chondrocytes, osteoblast and osteoclast existed in the control group. (2) In experimental group and control group, a large quantity of callus was found 4 and 8 weeks; ossification of chondrocytes with weave bone formation were found 4 weeks and many osteocytes and weave bones and laminar bones were found 8 weeks. (3) In the 12th week, the complete ossification of implant with well bone remodeling, a large number of mature osteocytes and laminar were found in experimental group and control group, and CHAP still existed in the experimental group; the defect area filled with fibro-scar tissue and only many fibroblasts could be seen in blank control group. (4) X-ray findings were the following: In experimental and control groups, callus formation could be seen 2 weeks postoperatively, more callus formed 4 weeks, the bone defect area disappeared and CHAP scattered in the callus 8 weeks; the fracture line disappeared and medullary cavity became united (in control group); and in the 12th week, the cortex became continuous, the medullary cavity became united, and remodeling completed, while bone defect was not still united in blank control group. The maximal torque and torsional stiffness in the experimental group is higher than those in the control group 2 weeks (P lt; 0.05), but there was no significant difference (P gt; 0.05) between the two groups 4, 8, 12 weeks after repair. CONCLUSION: The compound of CHAP-FS-SAI has good biological compatibility, and it can be used for one kind of bone substitute material to repair the bone defect.
There were several methods, such as free single and folded fibulae autograft, composed tissue autograft, however, it is still very difficult to repair long segment bone defect. In December 1995, we used free juxtaposed bilateral fibulae autograft to repair an 8 cm of femoral bone defect in a 4 years old child in success. The key procedure is to strip a portion of the neighboring periosteal sleeve of juxtaposed fibulae to make bare of the opposite sides of the bone shafts, suture the opposite periosteal sleeves, keep the nutrient arteries, and reconstruct the blood circulation of both fibular by anastomosis of the distal ends of one fibular artery and vein to the proximal ends of the other fibular artery and vein, and anastomosis of the proximal ends of the fibular artery and vein to lateral circumflex artery and vein. After 22 months follow up, the two shafts of juxtaposed fibulae fused into one new bone shaft. The diameter of the new bone shaft was nearly the same as the diameter of the femur. There was only one medullary cavity, and it connected to the medullary cavity of femur. This method also cold be used to repair other long segment bone defect.
To observe the collagen-hydroxylaptite composite in the repair of bone defect, ten minipigs were chosen to make a mandibular dafect measuring 2 cm in diameter and the composite was implanted, while the use of autogenous bone graft and the blank wese served as control. On the 4, 8, 12, 24 and 48 weeks after the operation, the animals were sacrificed and the samples were examined under light microscope. The result showed that: no infection or necrosis occurred. The composite coalesced with host bone and the outcome was similar to that of the autogenous bone graft. No foreign body giant cells or vacuum left from osteonecrosis was observed. It was suggested that the composite had the advantage of abundant supply, easy to handle and no harm. The biocompatibility was good and might be hopeful as a bone substitute.
OBJECTIVE: To study the reparative and reconstructive methods for the large bone defect due to the excision of bone tumor. METHODS: According to the size and shape of the bone defect, we selected the proper bone and joint or manipulated bone segment of the profound hypothermia freezing allograft and gave locked intramedullary nails or steel plate and screws for stable internal fixation. RESULTS: In the 22 cases, 20 survived without tumor and 2 died. One patient treated with the allograft of semi-knee joint was found rejection. Then the wound did not heal. After the skin flap grafting was performed, the wound still did not heal, so the patient accepted amputation(4.5%). In the other 21 cases, the X-ray and 99mTc SPECT showed some callus or concentration of nuclein which implied bone union. According to Markin bone graft criterion, the excellent rate of function recovery was 81.8%. CONCLUSION: Allografting of bone and joint is a good and workable method in repairing and reconstructing the bone defect due to the excision of bone tumor. It should be further studied and be applied.
Objective To prepare a self-made compound, hemostatic jelly with polylactic acid(PLA), which has the hemostatic and absorbable effect on injured cancellous bone. Methods Two bone defects of 5 mm in diameter and 4 mm in depth were subjected on 20 health rabbits by drilling through their either outside plate of the iliac, and were filled with hemostatic jelly(group A), bone wax(group B) and blank(group C) respectively. Hemostasis were observed and recorded after 1 and 10 minutes. Five specimens were harvested at 2, 4, 8 and 12 weeks postoperatively for histological observation. Results ① Hemostatic effect: Bleeding of injured spongy bone stopped within 10 minutes after the treatment of hemostatic jelly and bone wax, but bleeding of balnk did not stop. Hemostatic jelly and bone wax adhered to bone defects firmly within 10 minutes was after the treatment. ② Absorbable effect: Hemostatic jelly and bone defects have not changed visibly in the first 2 weeks. With histological observation 4 to 8 weeks after the operation, hemastatic jelly was absorbed gradually and replaced by osteogenous tissue. It was absorbed completely after 8 to 12 weeks. Bone wax was not absorbed after 12 weeks, no new bone tissue was observed at bone wax area. The blank was replaced by connective tissue and osteogenous tissue partially after 12 weeks. Conclusion The compound hemostatic jelly manifests both hemostatic and absorbable effects on injured cancellous bone and may substitute for bone wax in clinical application.
Abstract To restore the bone defect after curettage of bone cyst, hydroxyapatite bioactive microcrystal glass (HBG) was used. From 1990 to 1995, HBG was applied in 17 cases. The bone involved were humerus, femur, tibia and fibula. Among them, 6 were complicated with pathological fracture. After eradication of the focus, the cyst was filled in ZnCl2 powder and irrigated with saline, then particles or segments of HBG were implanted into the cavity. The fracture were fixed with Enders rod. All the extremities were immobilized with plaster splint for about 6 to 8 weeks. Three months later, the lower limbs began to have functional exercises. By X-ray examination, the border between HBG and bone was clear in 2 weeks, after 1 month the clear border become blurred, and 2 months after operation, HBG was intermingled with bone. After 1 year there was neither absorption of bone nor HBG. No recurrence of the aptic lesion occurred in 1 year. HBG was a kind of artificial bone composed of hydroxyapatite and bioactive microcrystal glass, the latter contained silicon.It was characterized by its bioactivity, osteoinductivity and good tissue compatibility. The microcrystal would facilitate the growth of osseous tissues, which caused HBG intermingled with the surrounding bone. The source of HBG was abundant. It might be an ideal artificial bone.
Objective To investigate the feasibility of imaging of bone marrow mesenchymal stem cells (BMMSCs) labeled with superparamagnetic iron oxide(SPIO) transplanted into coronary artery in vivo using magnetic resonance imaging (MRI), and the redistribution of the cells into other organs. Methods BMMSCs were isolated, cultured from bone marrow of Chinese mini swine, and double labeled with SPIO and CMDiI(Cell TrackerTM C-7001). The labeled cells were injected into left anterior descending coronary artery through a catheter. The injected cells were detected by using MRI at 1 week,3weeks after transplantation. And different organs were harvested and evaluated the redistribution of transplanted cells through pathology. Results The SPIO labeled BMMSCs injected into coronary artery could be detected through MRI and confirmed by pathology and maintained more than 3 weeks. The SPIO labeled cells could be clearly imaged as signal void lesions in the related artery. The pathology showed that the injected cells could be distributed into the area of related artery, and the cells injected into coronary artery could be found in the lung, spleen, kidney, but scarcely in the liver, the structures of these organs remained normal. Conclusion The SPIO labeled BMMSCs injected into coronary artery can be detected by using MRI, the transplanted cells can be redistributed into the non-targeted organs.
ObjectiveTo investigate the bone regeneration potential of cell-tissue engineered bone constructed by human bone marrow mesenchymal stem cells (hBMSCs) expressing the transduced human bone morphogenetic protein 2 (hBMP-2) gene stably. MethodsThe full-length hBMP-2 gene was cloned from human muscle tissues by RT-PCR and connected into a vector to consturct a eukaryotic expression system. And then the gene expression system was transduced to hBMSCs with lipidosome. hBMSCs were transfected by hBMP-2 gene (experimental group) and by empty plasmid (negative control group), untransfected hBMP-2 served as blank control group. RT-PCR, dot-ELISA, immunohistochemical analysis and ALP activity were performed to compare and evaluate the situation of hBMP-2 expression and secretion after transfection. hBMSCs transfected by hBMP-2 gene were seeded on hydroxyapatite (HA) and incubated for 4 days to construct the hBMP-2 gene modified tissue engineered bone, and then the tissue engineered bone was observed by the inverted phase contrast microscope and scanning electron microscope. Then the hBMP-2 gene modified tissue engineered bone (group A, n=3), empty plasmid transfected hBMSCs seeded on HA (group B, n=3), hBMSCs suspension transfected by hBMP-2 gene (group C, n=3), and hBMP-2 plasmids and lipidosome (group D, n=3) were implanted into bilateral back muscles of nude mice. The osteogenic activity was detected by HE staining and alcian blue staining after 4 weeks. ResultsAt 48 hours and 3 weeks after transfection, RT-PCR and dot-ELISA results indicated that the transfected hBMSCs could express and secrete active and exogenous hBMP-2 stably. The immunohistochemical staining was positive, and the ALP activity in the transfected hBMSCs was significantly higher than that in two control groups (P < 0.05). The transfected hBMSCs had a good attaching and growing on the three-demension suface of HA under inverted phase contrast microscope and scanning electron microscope. In vivo study indicated that a lot of new bone formation was obviously found at 4 out of 6 sides of back muscles in group A. Some new bone formation at both sides of back muscles was observed in 1 of 3 mice in group B. No new bone formation was found in group C. A few new bone formation was observed at one side of back muscles in group D. ConclusionThe tissue engineered bone constructed by hBMP-2 gene modified hBMSCs and HA is able to express and secrete active hBMP2 stably and can promote new bone formation effectively in muscles of nude mice.
Objective To review the current concepts of gene therapy approachesmediated by adenovirus vectors for bone trauma and bone disease. Methods The recent literature concerned gene therapy mediated by adenovirus vectors was reviewed, which provides new insights into the treatments of bone trauma and bone disease. Results Adenovirus vectors was efficient, achieved high expression after transduction, and could transfer genes to both replicating and nonreplicating cells, such as osteoblasts, osteoclasts, fibroblasts, chondrocytes, bone marrow stromal cells, etc. Gene therapy mediated by adenovirus vectors achieved affirmative results in enhancing bone union and in curing bone diseases, such as osteoporosis and rheumatoid arthritis. Conclusion Gene therapy mediatedby adenovirus offers an exciting avenue for treatment of bone trauma and bone diseases.
OBJECTIVE: To construct tissue engineering bone with bio-derived materials and bone marrow stromal cells (MSCs), and to investigate the effect of allogeneic engineering bone implants on healing of segmental bone defects. METHODS: MSCs being aspirated aseptically from tibial tuberosities of young rhesus monkeys were induced into osteoblasts in vitro and then were cultured and marked with 5-bromo-2-deoxyuridine (BrdU). Tissue engineering bones were constructed with these labeled osteoblasts being seeded onto bio-derived materials made from fresh human bones which were treated physically and chemically, Then the constructs were implanted in 15 allogeneic monkeys to bridge 2.5 cm segmental bone defects of left radius as experimental groups, bio-derived materials only were implanted to bridge same size defects of right radius as control group. and, 2.5 cm segmental bone defects of both sides of radius were left empty in two rhesus monkeys as blank group. Every 3 monkeys were sacrificed in the 1st, 2nd, 3rd, 6th and 12th weeks postoperatively and both sides of the implants samples were examined macroscopically, histologicaly, and immunohistochemicaly. The two monkeys in blank group were sacrificed in the 12th week postoperatively. RESULTS: Apparent inflammatory reactions were seen around both sides of the implants samples in the 1st, 2nd, 3rd weeks, but it weakened in the 6th week and disappeared at the 12th week. The labeled osteoblasts existed at the 6th week but disappeared at the 12th week. The bone defects in experimental group were repaired and the new bone formed in multipoint way, and osteoid tissue, cartilage, woven bone and lamellar bone occurred earlier when compared with control group in which the bone defects were repaired in ’creep substitution’ way. The bone defects in blank group remained same size at the 12th week. CONCLUSIONS: Engineering bones constructed with bio-derived materials and MSCs were capable of repairing segmental bone defects in allogeneic monkeys beyond ’creep substitution’ way and making it healed earlier. Bio-derived materials being constituted with allogeneic MSCs may be a good option in construction of bone tissue engineering.