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.
Objective To investigate the method and clinical effect of free iliac flap grafting in repairing the tibia traumatic osteomyelitis complicated withboneskin defect. Methods From June 2001 to February 2006，28 patients with tibia traumatic osteomyelitis complicated with boneskin defect were treated with free iliac flap grafting at stageⅠ. There were 18 males and 10 females, with an average of 32.5 years(1868 years). There were traffic injury in 11 cases, bruise in 6 cases, explosive injury in 5 cases, machinery injury in 4 cases, and falling injury in 2 cases. The disease courses of patients were 1-6 months. All patients had been treated by 26 operations. The wounds located at the mid and upper tibia in 13 cases, and the inferior tibia in 15 cases. The length of free iliac was0.5-6.0 cm and the size of the flap ranged from 4.5 cm×3.5 cm to 28.0 cm×16.0 cm.The external fixation were applied in 18 cases, and steel plate were applied in 10 cases. The donor sites were sutured directly. Results All of the flaps survived completely. The wounds healed by first intention in 26 cases and by second intention in 2 cases. The donorsites healed by first intention. Twentyeight patients were followed up for 6 to 56 months(mean, 30 months).The appearances of the flaps were satisfactory and the colour was similar to recipient site. All grafted bone united 2-14 months (mean，4.6 months) after operation according to X-ray examination. In 20 patients who did not achieved union before operation, fracture healed 2 to 6 months after operation(mean, 3.2 months). Osteomyelitis recurred 12 months after operation in 2 cases and healed by nidus clearing. Conclusion Free iliac flap which used to repair tibia traumatic osteomyelitis complicated with boneskin defect, can repair the defect at stageⅠand enhance the antiinfectious ability. It isone of appropriate and effective clinical methods.
Objective To compare and evaluate the capability of pure autogenous bone and the enhanced autogenous bone combined with bone morphogenetic protein in bone repair of femoral head. Methods Eighteen femoral heads of 9 dogs weredrilled by trephine, 4 mm in diameter, followed by respective implantations of autogenous bone grafting (group B) and of the enhanced autogenous bone composite, combined with bone morphogenetic protein (group C), with the selfrepair of bone defect as the control (group A). Three, six, nine weeks after the operation, radiological examination, computerized tomography, light and electronic microscopes were performed to investigate the bone healing of the defect in the femoral head. Results In group A, it could be observed that there washematoma organization and delayed woven bone formation in the 3rd week after operation, and therewas little replacement of woven bone by bone trabecula in the 9th week; in group B, the autogenous bone implanted were dead in the 3rd week and maintained in situ in the 9th week; in group C, active new bone formation, either endochondral or intramembranous ossification, was found in the 3rd week and entire repair of the bone defect by bone trabecula in the 9th week after operation. Conclusion The enhanced autogenous bone combined with bone morphogenetic protein could promote reconstruction of the bone defect in femoral head, superior to pure autogenous bone which could provide a framework for the new bone formation.
In the study of repair of massive bone defect with free vascularized fibula graft, 13 cases were reported, in which traumatic defect in 7 cases, segmental resection of bone from tumors in 5 cases and osteomylitis in 1 cases. They all were treated successfully with vascularized fibular graft. After a follow-up of 6 months to 7 year, bone healing was observed with satisfactory and rehabilitation of functions. In one case, fatigued fracture occured twice due to early walking. It was concluded that free vascularized fibular graft was very helpful in the repair of massive bone defect, but prolonged external fixation after operation might be important to prevent fractur of grafted bone.
OBJECTIVE: To investigate the feasibility of coralline hydroxyapatite (CHA) as scaffolds in bone tissue engineering. METHODS: The bone marrow stromal cells from 4-month New Zealand rabbits were harvested and cultured in vitro. After multiplied, dexamethasone was used to promote the osteoblastic phenotype of the cells. The cells were harvested and then seeded into CHA. By means of tissue engineering technique, osteoblastic cells/CHA complex were formed. The complex were implanted subcutaneously in nude mice. The CHA alone was implanted as control. Bone regeneration was assessed 6, 8 weeks after implantation by histological and roentgenographic analysis. RESULTS: After six weeks of implantation, x-ray film showed high-density signal, osteoid tissue formed under histological examination. Large amount of new bone were formed and connected to trabecularism 8 weeks after implantation in the experimental group. While in the control group, there were no new bone formation, but amount of fiber tissue grew into the pore of CHA 8 weeks after implantation. CONCLUSION: CHA may be used as a good scaffold material for bone tissue engineering.
Objective To evaluate the host immune reaction against adenovirus mediated human bone morphogenetic protein 2 (Adv-hBMP-2) gene therapy in repairof tibial defects. Methods Twelve goats were made 2.1 cm segmental defects in he tibial diaphysis and divided into 2 groups. AdvhBMP2 transfected marrow mesenchymal stem cells(MSCs) and untransfected MSCs were implanted into the defect sites of transfected group(n=7) and untransfected group (n=5), respectively. The defect repair was observed by X-ray films after 4, 8, 16 and 24 weeks of transplantation and cellular and humoral immune reactions to adenovirus were assayed before implantation and after implantation. Results More bony callus was found in the bone defects of transfected group. The healing rates were 6/7 in transfected group and 2/5 in untransfected group, respectively at 24 weeks after implantation. The mixed culture of lymphocytes and MSCs showed that the lymphocytes stimulation indexes (SI) increased 14 days after implantation, and there was significant difference between the transfected group (4.213±1.278) and the untransfected group(－0.310±0.147，Plt;0.05); SI decreased after 28 days, but there was no significant difference between the transfected group (2.544±0.957) and the untransfected group (3.104±0.644，Pgt;0.05). After 14, 28, 49, and 120 days of treatment, the titer values of neutralizing antibody against Adv-hBMP-2 (log0.1) were 2.359±0226, 2.297±0.200, 2.214±0.215 and 2.297±0.210 in transfected group, and -0.175±0.335, -0.419±0.171, 0±0.171 and 0.874±0.524 in untransfected group, being significant differences betweentwo groups(Plt;0.05). Conclusion Adenovirus mediated BMP-2gene therapy can cause cellular and humoral immune reactions against adenovirus, which can eliminate the influence of adenoviral genes and proteins within a certain period.
Abstract In order to repair the bone defect afteroperation of benign lesion of extremity, the fetal demineralized bone was applied in 10 cases. These cases were followed up for 6 months to 8 years. The results showed that the grafted bone was integrated with the host bone in 6 months. Noadverse effect was found. The demineralized bone did not induce rejection. The advantages of using fetal demineralized bone were as follows: easily obtainable,its preparation and method of storage simple, and low finacial cast.
Objective To give a prel iminary experimental evidence and to prove chitosan and allogeneic morsel ized bone as potential bone substitutions in repairing rabbit radius segmental defect. Methods Chitosan and allogeneic morsel ized bone were mixed with various ratios (1 ∶ 5, 1 ∶ 10, 1 ∶ 25, 1 ∶ 50, and 1 ∶ 100). After preparation, the physicaland chemical properties of the composites were prel iminary detected; the composites at the ratios of 1 ∶ 50 and 1 ∶ 25 had good physical and chemical properties and were used for the animal experiment. The radius segmental defects of 15 mm in length were made in 50 adult New Zealand white rabbits (weighing 2.5-3.0 kg), then the animals were divided into 2 groups. In groups A and B, chitosan/allogeneic morsel ized bone composites were implanted at the ratio of 1 ∶ 50 and 1 ∶ 25, respectively. After 1, 2, 4, 8, and 12 weeks of operation, the gross, histological, immunohistochemical observations were performed. Before the rabbits were sacrified, X-ray films were taken; the serum calcium and alkal ine phosphatase (ALP) concentration were measured; and the biomechanical measurement was carried out at 12 weeks. Results The results of gross observation were essentially consistent with those of the X-ray films. The histological observation showed that the bone formation was earl ier in group A than in group B; the amount of new bone formation in group A was more than that in group B; and the bone forming area in group A was bigger than that in group B (P lt; 0.05) at 4 and 8 weeks after operation. The immunohistochemical staining showed that vascular endothel ial growth factor and insul in-l ike growth factor receptor II proteins expressed in the cytoplasm of 2 groups after 4 and 8 weeks, and the expression in group A was higher than that in group B (P lt; 0.05). There was no significant difference in the serum calcium concentration between 2 groups at each time point (P gt; 0.05). After 4 and 8 weeks, the ALP concentration in group A was significantly higher than that in group B (P lt; 0.05). After 12 weeks, the radius maximum bending loads of groups A and B were (299.75 ± 27.69) N and (278.54 ± 17.09) N, respectively, showing significant difference (t=4.045,P=0.002). Conclusion The composite of chitosan and allogeneic morsel ized bone has good osteogeneic activity and can beused as a bone tissue engineering scaffold, and the optimum ratio of chitosan to allogeneic morsel ized bone was 1 ∶ 50.
OBJECTIVE To introduce a new method of bone defect repairing after bone cyst curettage. METHODS Eight cases with bone cyst were treated with this new method. The pieces of autogenous periosteum were implanted into the hematoma within the enveloped bone defect created after the bone cyst curettage. Among these patients, there were 5 males and 3 females, aged from 14 to 36 years old. All the lesions located in the upper of femur except one being located in humerus. The results were evaluated through the postoperative radiological findings with the preoperative ones and analysis of clinical functions. RESULTS All the patients were followed up for 2 to 11 years. X-ray films showed that osteogenesis developed well and that the enveloped bone defects had been repaired. No recurrence was found and the function of the affected limbs were maintained. CONCLUSION Autogenous periosteum grafting is effective in the treatment of solitary bone cyst.