From January 1984 to November 1997, the boiling xenogenic bone (porcine and bovine bone) was applied in 65 patients. The xenogenic bone was used to promote bone healing in 24 cases, intramedullary bone graft in 37 and osteomyelitis in 4. All of the patients were followed up for 2 to 35 months. The results showed that in five cases there was infection after operation, and all other the wounds had primary healing. The xenogenic bone seemed to induce rejection in vivo. In the sevious cases immunosuppressive treatment was often needed. The volume of the bone grafted and the extent of the periosteum being stripped seemed to be important whether xenogenic bone graft would be successful or. There were lots of problem needed investigation.
Objective To investigate the effect of anti-infective reconstitutedbone xenograft (ARBX) as primary grafting on repair of a segmental contaminateddefect in canine radius. Methods The contaminated segmentaldefects of 1.5 cm were made in both radius of 8 canine and 1 ml of staphylococal suspension was injected into the defect region at a concentration of 5×106 CFU/ml. ARBX(experimental side) or RBX(control side) was implanted into the two sides of the defects respectively as primary grafting followed by internal fixation. The results were compared between the two grafting materials in repairing the contaminated segmental defect. Results In ARBX side, the defects were repaired completely in 5 cases and partially in 1 case, and there existed no osteomyelitis in all cases; while in RBX side, the defects were repaired partially in 1 case and were not repaired in 5 cases after 6 months of operation, and there existed osteomyelitis in all cases. Conclusion Besides its b osteoinductive and osteoconductive activity, ARBX is highly antibacterial and can be used as primary grafting in repairing contaminated segmental defects.
Objective To study efficiency of vascularized bone graft combining with reconstituted bone xenograft (RBX) in repairing bone defect and the expression of the vascular endothelial growth factor (VEGF) in serum. Methods From January 1998 to December 2002, 27 cases of bones defects were treated and randomly divided into 3 groups according to different repair materials: group A (the vascularized bone graft-RBX group, n=9), group B (the vascularized bone graft group, n=10)and group C(the RBX group, n=8). The bone defect repair, the bone healing time and the bone graft resorption were observed by radiograph after 3 months, 6 months and 12 months of operation, and the expression of VEGF in serum was assayed with lumino-enzyme immunoassay before operation and after operative 2 weeks, 4 weeks, 6 weeks and 8 weeks respectively. Results The X-ray films showed that the bonehealing was achieved in 8 cases of group A, in 6 cases of group B and in 3 cases of group C after 3 months; in 1 case of group A, respectively in 3 cases of both group B and group C after 6 months. The bone graft resorption was observed in1 case of group B and in 2 cases of group C after 12 months. The serum VEGF values after operative 2 weeks and 4 weeks were higher than those before operation in all of 3 groups(Plt;0.05), and the VEGF values of groups A and B were higher than that group C(Plt;0.05) after 4 weeks. There were no significant differences (Pgt;0.05) in serum VEGF level between postoperative 6, 8 weeks and preoperation in 3 groups. Conclusion The expression of serum VEGF obviously increase in the early period of bone transplanting, it is value of clinical evaluation of reparative efficiency of bone defect.
Objective To investigate a new grafting material of bone xenograft with b bone inductive and conductive capacity. Methods Based on successful clinical application of the reconstituted bone xenograft (RBX), a new xenograft was made by combining recombinant human bone morphogenetic protein-2 (rhBMP-2) with antigen-free bovine cancellous bone (BCB). Sixty male BALB/C mice aged 4 weeks were divided into study group of 30 and control group of 30 randomly. rhBMP-2 / BCB was implanted in the left thigh muscle pouch in the study group andBCB in the control group. The mice were sacrificed at 7 d, 14d and 21d after implantation. Inductivity of rhBMP-2/BCB was detected by histological observation and biochemical determination of the samples. Results Histological examinationshowed that rhBMP-2/BCB induced chondrogenesis on the 7th day, with woven boneformed on the 14th day, and lamellar bone and marrow on the 21st day, while BCBfailed to induce chondrogenesis or osteogenesis on the 7th, 14th and 21st days. The alkaline phosphatase activities and calcium content in study group were higher than those in control group with significant difference (P＜0.01). Conclusion rhBMP-2/BCB is an ideal grafting material with b bone inductive and conductive capacity without evoking immune reaction.
【Abstract】 Objective To produce a new bone tissue engineered carrier through combination of xenograft bone (X)and sodium alginate (A) and to investigate the biological character of the cells in the carrier and the abil ity of bone-forming in vivo, so as to provide experimental evidence for a more effective carrier. Methods BMSCs were extracted from 2-week-old New Zealand rabbits and the BMSCs were induced by rhBMP-2 (1 × 10-8mol/L). The second generation of the induced BMSCs was combined with 1% (V/W) A by final concentration of 1 × 105/mL. After 4-day culture, cells in gel were investigated by HE staining. The second generation of the induced BMSCs was divided into the DMEM gel group and the DMEM containing 1% A group. They were seeded into 48 well-cultivated cell clusters by final concentration of 1 × 105/mL. Seven days later, the BMP-2 expressions of BMSCs in A and in commonly-cultivated cells were compared. The second generation of the induced BMSCs was mixed with 2% A DMEM at a final concentration of 1 × 1010/mL. Then it was compounded with the no antigen X under negativepressure. After 4 days, cells growth was observed under SEM. Twenty-four nude mice were randomly divided into 2 group s (n=12).The compound of BMSCs-A-X (experimental group) and BMSCs-X (control group) with BMSCs whose final concentrat ion was 1 × 1010/mL was implanted in muscles of nude mice. Bone formation of the compound was histologically evaluated by Image Analysis System 2 and 4 weeks after the operation, respectively. Results Cells suspended in A and grew plump. Cell division and nuclear fission were found. Under the microscope, normal prol iferation, many forming processes, larger nucleus, clear nucleolus and more nuclear fission could be seen. BMP-2 expression in the DMEM gel group was 44.10% ± 3.02% and in the DMEM containing 1% A group was 42.40% ± 4.83%. There was no statistically significant difference between the two groups (P gt; 0.05). A was compounded evenly in the micropore of X and cells suspended in A 3-dimensionally with matrix secretion. At 2 weeks after the implantation, according to Image Analysis System, the compound of BMSCs-A-X was 5.26% ± 0.24% of the totalarea and the cartilage-l ike tissue was 7.31% ± 0.32% in the experimental group; the compound of BMSCs-X was 2.16% ± 0.22% of the total area and the cartilage-l ike tissue was 2.31% ± 0.21% in the control group. There was statistically significant difference between the two groups (P lt; 0.05). At 4 weeks after the operation, the compound of BMSCs-A-X was 7.26% ± 0.26% of the total area and the cartilage-l ike tissue was 9.31% ± 0.31% in the experimental group; the compound of BMSCs-X was 2.26% ± 0.28% of the total area and the cartilage-l ike tissue was 3.31% ± 0.26% in the control group. There was statistically significant difference between the two groups (P lt; 0.05). Conclusion The new carrier compounding A and no antigen X conforms to the superstructural principle of tissue engineering, with maximum cells load. BMSCs behave well in the compound carrier with efficient bone formation in vivo.
Objective To study the influence of the immersed time by hydrogen dioxide on the characteristics of bovine cancellous bone granules in various periods. Methods Ten 24-month-old Qinchuan bovine, male or female, weighing 150-170 g, were selected. Cancellous bone granules from metaphysic of bovine long bone were cut into cubes of 5 mm × 5 mm ×5 mm and immersed by 8.8 mol/L hydrogen dioxide for 0, 12, 24, 36, 48, 60 and 72 hours separately. Determination of ash, scanning electron microscope, X-ray energy spectrum and micro CT were used to investigate the changes of composition, structure and qual ity of bone. Results With the immersed time increasing, the contents of organics in the bone cancellous were reduced gradually, and obviously decreased during the periods of 0 to 24 hours and 60 to 72 hours (P lt; 0.05). The contents of calcium and phosphorus decreased gradually, they could not be detected almost after 60 days (P lt; 0.05). Bone mineral density and bone mineral content were decreased obviously after 60 hours (P lt; 0.05). The bone trabecula became sl immer and trabecular spacing became larger. Conclusion Hydrogen dioxide can be used to remove the antigen in xenogeneic bone; however as the time increasing (more than 60 hours) the composition and structure will be damaged. Thus it is important to control the immersed time for maintaining the biological characteristics of xenogeneic bone substitute as well as el iminating antigen by hydrogen dioxide.
Objective To observe the changes of immune status in recipient after implanting with xenogeneic acellular bone matrix (ACBM). Methods Twenty rabbits were randomly divided into 4 groups. Autograft，ACMB and bone soaked in alcohol were implant into the 3 experimental groups separately, and No-treatment was done as control group. The CD4+,CD8+,CD25+T lymphocytes in blood were detected by flow cytometer at 1, 2, 4 and 6 weeks after operation. After 2 and 6 weeks of implantation, the changes of bone and tissue were observed by histology. Results After 2-6 weeks, CD4+ and CD8+ T cells were significantly higher in the implantedgroup of bone soaked in alcohol than that in the other 3 groups(Plt;0.05) and there wasno statistically significant difference in the other 3 groups(Pgt;0.05). After 2 weeks, CD25+ T cells were significantly higher in the implanted group of bone soakedin alcohol than that in the other groups. In the 2nd week, there were inflammatory infiltration with a predominance of granulocytes. In the 6th week, there were many fibroblasts instead of granulocytes with a few lymphocytes and cartilage island formed in the implanted groups of autograft and ACMB. Conclusion ACBM implanting has low influence on cellular immunity in recipient.
It is reported in this paper that defect of chest wall of dogs were repaired by hetcrotransplantation of pig bone. The shape of original chest wail were achieved following operation. Histologic study showed that the grown between trabeculae with immersion that method is not only to have same function of other reparing materials,but there is no rejection.
Objective To investigate the clinical effect of reconstructed bone xenograft plus buttress plate (T or L type) fixation in treating tibial plateau fracture. Methods From June 2001 to March 2003, 32 cases of tibial plateau fractures were treated by means of open reduction,reconstructed bone xenograft plus buttress plate (T or L type) fixation. There were 23 cases of bumper fracture, 5 cases of falling injury and 4 cases of crush injury by a weight; 20 males and 12 females, aged from 18 to 69 years with an average of 38 years. All patients had close fracture. Results All the patients were followed upfor 9 months to 23 months, tibial plateau fracture healed satisfactorily without sunken articular surface. According to Pasmussen criterion, the results were excellent in 16 knees, good in 12knees and moderate in 3 knees. The satisfactory rate was 87.5%. Conclusion Reconstructed bone xenograft plus buttress plate internal fixation has good effect in treating tibial plateau fractures because it can avoid the complication of transplantation of ilium.
Objective To develop a deantigenated porcine bone graft through enzyme treatment and to study the biomechanical properties and osteoinductivity of the xenogeneic bone graft. Methods Deantigenated xenogeneic bone was prepared from porcine bone by a series treatment including α-galactosidase (α-Gal) treatment, freezedrying and irradiation at a does of 25 kGy. Samples were divided into 4 groups according to the treatment methods: fresh bone (group A); deantigenated bone (group B); deantigenated and freezedried bone (group C); deantigenated-freezedried-irradiated bone(group D). SEM observation to group B samples was performed and the diameters of the caves of the porcine cancellous bone were measured. The α-Gal contents of samples of groups A, B, D were measured by ELISA. The effects of different treatments on porcine bone mechanic properties were evaluated through compressive test of 4 groups. The prepared porcine cortical bone were demineral ized and ectopically implanted into muscle groups of hind l imbs of Wistar rats as experimental group, and the demineral ized cortical bone which were inacitviated by high temperature and pressure were implanted as control group. Histological observation was performed and ALP activity was tested at different time postoperatively to investigate the osteoinductivity of the xenogeneic bone implants. Results The porous structure of prepared porcine cancellous bone was similar to that of human cancellous bone. The diameters of the caves were between 150-600 μm. The A value of the groups A, B, D was 0.358 ± 0.027, 0.191 ± 0.011, 0.191 ± 0.009, respectively, with statistically differences between groups (P lt; 0.05). While the biomechanical properties among 4 groups had no statistically difference (P gt; 0.05). Histological observation showed mesenchymal cells immigrated into cartilage and converted into chondrocytes at 3 weeks postoperatively. Cartil iage was formed at 4 weeks and osteoid and more adult cartilage was formed at 6 weeks within the implants of experimental group, while there was no bone formation in control group. ALP activity of experimental group at different times were obviously higher than that of the control group (P lt; 0.05). Conclusion The main xenogeneic antigen of the porcine bone was removed while the mechanic properties and osteoinductivity remained, thus it may be a suitable bone substitute for cl inical use.