Objective To study the effect of vascular endothelial cell growth factor (VEGF) on repair of bone defect with cortical bone allograft. Methods Forty five New Zealand white rabbits, weighted 2.5-3.0 kg, were made bone defect model of 1.5 cm in length in the bilateral radii and then were randomly divided into 3groups. The defect was repaired with only cortical bone allograft in the control group, with the cortical bone allograft and local injection of human recombinantVEGF in the experimental group, and with the cortical bone allograft and abdominal injection of VEGF PAb3 in the antagonist group. Roentgenography, immunohistochemical staining and tetracycline labelling were carried out to evaluate the reparative results 1, 3, 5, 8 and 16 weeks after operation. Results Immunohistochemical staining results showed that a great deal of blood vessels formed in the experimental group, and the number of blood vessels increased gradually with the time and reached the highest value at the 8th week. Tetracyclinelabelling showed the same result.The best results in callus formation, ossification rate and count of microvascular density were shown in the experimental group, while those in the control group were significantly better than those in the antagonist group (Plt;0.05),but there was no significant difference between the experimental group and the control group at the 8th week and the 16th week (Pgt;0.05). Conclusion VEGF can accelerates the bone formation and angiogenesis in the bone allografts, thus it can promote the repair of bone defects.
Objective To investigate effects of the basic fibroblast growth factor (bFGF) and fibronection (FN) on the osteoblast adhesion on the bio-derived bone. Methods The third generation of the osteoblast was treated with bFGF 0.1, 1, 10, and 100 ng/ml, respectively, and then was seeded in the bioderived bone, which had been modified with FN 0.1, 1, 10, and 100 μg/ml, or Polylysine, respectively. The cell adhesion was measured by the MTT assay. The cell density and the cell appearance were observed by the scanning electron microscope. The abovementioned procedures were repeated by an application of the GRGDS peptide. Results Both FN and bFGF could enhance the osteoblast adhesion efficiency on the bioderived bone (Plt;0.05). However, the osteoblast adhesion efficiency could be significantly strengthened bya combined use of FN and bFGF. FN and bFGF had a significant synergistic effectin statistics (Plt;0.01), but Polylysine and bFGF had no such synergistic effect (P＞0.05). The combined use of FN and bFGF had a better effect on the cell density and the cell appearance than either of them when observed with the scanning electron microscope. Adhesion efficiency generated by the combined use of FN and bFGF was significantly blocked by the application of the GRGDS peptide. Conclusion The combined use of FN and bFGF has a significant synergistic effect on the osteoblast adhesion efficiency on the bioderived bone. This effect is probably mediated by the RGD-integrin α5β1 pathway.
Objective To evaluate the feasibility of poly-L-lactide(PLLA)/porcinederived xenogeneic bone(PDXB) composite as a scaffold for the bone tissue engineering. Methods The film and the scaffold of the PLLA-PDXB composite were respectively prepared by a solution casting method and a solution casting-particle leaching method. The composite film and scaffold were further treated by the surface alkaline hydrolysis. The surface morphology of the composite was observed by the scanning electron microscopy, and hydrophilicity degree of the composite was measured. The OCT-1 osteoblastlike cells were cultured and amplified in vitro as the seeding cells, which werethen implanted on the film and scaffold. The adherence rate, adherence shape,proliferating activity, and growing morphology of the OCT-1 osteoblastlikecells were observed on the film. Results The PDXB particle 50 μm in diameter on average had a similar phase structure to that of hydroxyapatite. But its Ca/P ratio was lower than that of hydroxyapatite. After the surface alkaline hydrolysis, the PDXB particle could be exposed on the surface of the PLLA-PDXB composite. The surface roughness and hydrophilicity of the PLLAPDXB composite were obviously enhanced. The cell adherence rate and the cell proliferation activity of the PLLAPDXB composite were higher than those of the pure PLLA material. The cells tended to grow on the exposed surface of the PDXB particles. The cells seeded on the composite scaffold could migrate to the inside of the composite scaffold and grew well. Conclusion The PLLA-PDXB composite has a good cell affinity, and this kind of composite can hopefullybecome a new scaffold material to be used in the bone tissue engineering.
OBJECTIVE To investigate the effect of percutaneous bone marrow graft for the management of nonunion of tibia. METHODS From March 1996 to June 2000, 56 cases with nonunion of tibia were treated by autogenous bone marrow graft. Among them, there were 38 males and 18 females, aged from 19 to 72 years. A marrow needle was inserted into the site of the nonunion under the X-ray, the autogenous bone marrow was injected into the site of nonunion. Compression bandage and appropriate immobilization material were applied after operation. This procedure was repeated every month, 2 or 3 times was needed. RESULTS 56 patients were followed-up for 4 months to 4 years and 2 months, averaged 2.8 years. Fracture healed in 53 cases and X-ray displayed fracture line disappeared and a great deal of continuous callus formed, and nonunion in 3 cases. CONCLUSION Percutaneous autogenous bone marrow graft can play a role in osteogenesis at the site of nonunion. It is easy to aspirate bone marrow and the operation is simple. It has clinical application value for the satisfactory effect.
To evaluate the method and effectiveness of anterior focus clearance with autograft bone fusion and internal fixation in treating of adjacent multivertebral tuberculosis in one-stage. Methods Between March 2007 and September 2009, 8 cases of thoracic vertebra tuberculosis were treated. Of 8 cases, 6 were male and 2 were female, aged 32 years on average (range, 20-42 years). The disease duration ranged from 8 to 14 months (mean, 10.2 months). Affected vertebrae included thoracic vertebrae in 35 cases and lumbar vertebrae in 11 cases; 5 vertebrae were involved in 4 cases, 6 vertebrae in 3 cases, and 8 vertebrae in 1 case. According to Frankel classification, there were 2 cases of grade C, 4 cases of grade D, and 2 cases of grade E. All patients had different kyphosis with the Cobb angle of (25.1 ± 6.6)°. All patients received antituberculous therapy 4-6 weeks preoperatively; after complete clearance lesions, autograft bone fusion and internal fixation were performed, and then antituberculous therapy was given for 18 months. Results All incisions healed by first intention. Eight patients were followed up 18-48 months (mean, 29 months). According to JIN Dadi et al. criterion, 7 cases recovered after first operation, 1 case of relapsed tuberculosis with sious was cured after re-focus clearance. The Cobb angle was (19.5 ± 4.2)° at 7 days after operation and was (22.3 ± 3.6)° at last follow-up, showing significant differences when compared with the preoperative value (P lt; 0.05). The nerve function of all cases were classified as Frankel grade E. CT scan showed bone graft fusion at 6-8 months after operation. No loosening or displacement of grafted bone and internal fixation occurred during follow-up. Conclusion The treatment of adjacent multivertebral tuberculosis by anterior focus clearance, intervertebral autograft, and internal fixation in one-stage is effective. Anterior bone fusion and internal fixation in one-stage can correct kyphosis effectively and rebuild spinal stabil ity, so it is a good choice for surgical treatment of adjacent multivertebral tuberculosis.
Objective To investigate the cl inical efficacy of the cancellous granule-type calcium phosphate cement in repair bone defect. Methods Between July 2008 and July 2009, 35 patients (42 l imbs) with fractures, nonunion, and benign bone tumor were treated with cancellous granule-type calcium phosphate cement. There were 32 males and 3 females,with an age range from 9 to 73 years (median, 41 years), including 24 l imb fractures (19 cases), 4 osteotomy for deformity of ulna and radius (2 cases), 2 femur intertrochanteric bony cysts (2 cases), 3 enchondroma (3 cases), 5 bone defect at donor il ium (5 cases), 3 nonunion (3 cases), and 1 lumbar spinal stenosis (1 case). The size of bone defect was 1-5 cm. Bone defect was repaired with cancellous granule-type calcium phosphate cement (1-5 g). Results All cases were followed up 8-23 months (13.7 months on average). Thirty-nine incisions (32 cases) healed by first intention and the suture was removed after 10-14 days. Incision dehiscence occurred in 2 cases, and wounds healed after second debridement and removal of artificial bone. Exudation of incision occurred in 1 case, and wound healed after symptomatic treatment. No local red swell ing, higher temperature, maculopapule, and ulceration of skin occurred at implantation site. X-ray films showed that bone graft fusion was achieved and bone defect was radically repaired at 6 months after operation and artificial bone was absorbed completely at 12 months. Conclusion Cancellous granule-type calcium phosphate cement can be used as a new graft bone material, which is suitable for defect fill ing after traumatic fracture, benign bone tumors, and il iac bone donor.
OBJECTIVE To manufacture adriamycin-porous tricalcium phosphate (A-PTCP) ceramic drug delivery system (DDS) as a possible method for bone defect treatment after bone tumor operation. METHODS A-PTCP DDS was made from putting adriamycin into PTCP. Thirty rabbits were divided randomly into group A(24 rabbits) and group B(6 rabbits). A-PTCP was implanted in the greater trochanter of the right femur in group A. Adriamycin were injected into veins in group B. Muscle around A-PTCP and plasma were taken out at different period. Adriamycin concentrations in muscle and plasma were measured by high performance liquid chromatography (HPLC). RESULTS A-PTCP could gradually release adriamycin over 10 weeks. Adriamycin concentrations in the muscle were higher than that in plasma. CONCLUSION A-PTCP may be a new method for repairing bone defects after bone tumor operation.
【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 summarize and review the heterogeneity of bone marrow derived stem cells (BMDSCs) and its formation mechanism and significance, and to analyze the possible roles and mechanisms in intestinal epithel ial reconstruction. Methods The related l iterature about BMDSCs heterogeneity and its role in intestinal epithel ial repair was reviewed and analyzed. Results The heterogeneity of BMDSCs provided better explanations for its multi-potency. The probable mechanisms of BMDSCs to repair intestinal epithel ium included direct implantation into intestinal epithel ium, fusion between BMDSCs and intestinal stem cells, and promotion of injury microcirculation reconstruction. Conclusion BMDSCs have a bright future in gastrointestinal injury caused by inflammatory bowl disease and regeneration.
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.