BMP-2 gene carried by biodegradable scaffold and fibrinous gel for repairing segmental radial defect in rabbit / 生物医学工程学杂志

Adenovirus carrying BMP-2 gene, after being mixed with fibrinous gel, was siphoned off on biodegradable scaffolds (PLA/PCL). The composite was used to repair 1.5 cm long radius defect in rabbits. Four methods were in use in the experiments: Ad-BMP-2 plus fibrinous gel and PLA/PCL (Group A), reconstructed hBMP-2 plus fibrinous gel and PLA/PCL (Group B), Ad-Lacz plus fibrinous gel and PLA/PCL (Group C), and fibrinous gel and PLA/PCL (Group D). Results showed that the defects treated in Group A were repaired with much more new bone regenerated, bridged earlier and stronger than those in Group B 12 weeks after operation. The defects treated in the other two groups could not attain osseous tissue healing. BMP-2 gene carried by biodegradable scaffold and fibrinous gel is easy to conduct and has very strong osteoinduction ability. It is really a good method to repair segmental bone defects.

Comparison between gene therapy and gradual release carrier for bone morphogenetic protein-2 in repairing bone defects / 生物医学工程学杂志

To compare the effects between gene therapy and gradual release carrier for bone morphogenetic protein-2 (BMP-2) in repairing bone defects, bone defects for 15 mm were created.on the bilateral radius in rabbits and treated with four kinds of implantations, ie, composite of transgeneic MSCs and PLA/PCL (Group A), composite of MSCs and gradual release carrier for BMP-2 (Group B), composite of MSCs and PLA/PCL (Group C), and PLA/PCL alone (Group D). After 4, 8, and 12 weeks of the operations, X-ray, histological examination, biomechanics analysis, and bone density measurement were conducted. Results showed that both osteoblasts and mesenchymal cells displayed strongly positive expression of BMP-2 in Group A after 4 weeks of the operation, the speed and quality of bone formation in Group A were much better than those in Group B. After 12 weeks of the operations, bone defects were completely repaired in Group A. BMP-2 gene therapy is really a good method to repair segmental bone defects.

A comparative study on seeding methods of human mesenchymal stem cells in bone tissue engineering / 生物医学工程学杂志

Seeding is the crucial step in bone tissue engineering. In current study, static and dynamic seeding methods for human bone marrow stem cells (hBMSCs) were compared. The methods for assay of DNA content in the constructs after seeding were adopted. The optic microscopy for histological apearance and the scanning electron microscopy (SEM) and fluorescent RT-PCR for osteogenic markers were performed. The maximal initial seeding concentration in static seeding is lower than that in dynamic seeding. Histology and SEM revealed the even distribution and spreading of cells in the dynamically seeded constructs, but showed cell aggregation in the statically seeded counterparts. Fluorescent RT-PCR again revealed stronger osteogenic potential of dynamically seeded constructs. Therefore, this initial study demonstrated that dynamic seeding of human bone marrow stem cells is a promising technique in bone tissue engineering.

Effects of human insulin-like growth factor 1 gene transfection on proliferation of NIH3T3 fibroblasts / 吉林大学学报(医学版)

Objective To study the effects of human insulin-like growth factor 1(hIGF-1) gene transfection on the proliferation of NIH3T3 fibroblasts.Methods The plasmid of pcDNA3.1-hIGF-1 was transfected into NIH3T3 fibroblasts by using Lipofectin method.The positive cell clones were selected with G418 and cultured for 4 weeks.The stable expression of hIGF-1 in the positive cells was determined by in situ hybridization and immunocytochemical analysis.MTT assay and flow cytometer analysis were used to observe the proliferation of NIH3T3 fibroblasts.Results hIGF-1 mRNA and protein expressed in NIH3T3 fibroblasts transfected with pcDNA3.1-hIGF-1 by in situ hybridization and immunocytochemical analysis.MTT assay showed the A value of transfected NIH3T3 fibroblasts rose,compared with untransfected NIH3T3 fibroblasts group,the difference was significant(P

Histological evaluation of calcium phosphate cement in augmentation of femoral neck fracture fixation / 中国组织工程研究

BACKGROUND: Structural characteristics of calcium phosphate cement (CPC) offer substantial mechanical integrity for fracture stabilization and fixation during the healing process, with particular applications in mechanically compromised osteoporotic bone.OBJECTIVE: To investigate the mechanism of the augmentation to fixation with CPC, comparing with screw fixation augmented by polymenthymethacrylate (PMMA) bone cement or with unaugmented screw fixation for femoral neck fractures in sheep by histological evaluation.DESIGN: Randomized controlled, duplicated observation and opening study.SETTING: Departments of Orthopeadics and General Surgery, the First Hospital of Jilin University; Department of Pathology, Basic Medical College of Jilin University; Department of Plastic Surgery, Aichi Medical University of Japan.MATERIALS: The experiment was completed in the Taonan Municipal Hospital of Jilin, Jilin University and Aichi Medical University of Japan from January 1999 to January 2004. A total of 45 adult sheep with mean age of 12.5 months were divided into three groups: unaugmentation group,CPC augmentation group and PMMA augmentation group with 15 in each group. Five sheep from each group were selected at 3, 6 and 12 weeks after operation. CPC was consisted of 75% α-tricalcium phosphate (α-TCP),18% tetracalcium phosphate (TeCP), 5% dicalcium phosphate dihydrate (DCPD) and 2% hydroxyapatite (HA). The solidify liquid was consisted of 5% sodium chondroitin sulphate, 12% sodium succinate and 83% water.The ratio between powder and water was 3:1. PMMA bone cement was combined with 97.4% methylmethacrylate, 2.6% N dimethyl-para-toluidine and hydroquinone.METHODS: ① Sheep from each group were anaesthetized by intravenous injection of pentobarbital sodium. The surgical steps were steotomy, drill,tap and fixation. An osteotomized bone at the base of right femoral neck of all groups was fixed by two cancellous bone screws of the diameter 4 mm through femoral neck at the site below great trochanter region. The cement material was filled into the screw hole before the screw insertion. ② CPC was injected into wells in CPC augmentation group, PMMA was injected into wells in PMMA augmentation group, but wells in unaugmentation group was not give any materials. ③After the maximum, compressive load was tested to detect intensity of healing bone, the specimens were fixed in 40%, 70%, 90% and 100% ethanol, dehydrated and stained, in the end embedded in PMMA resin. Serial histological specimens of 150-200 μm thickness were sliced along the long axis of the femoral neck with the microtom. The histological specimens also were taken for contact microradiography. The changes of the host bone and the new bone formation at the interface between cement and bone would be evaluated histologically until 3, 6 or 12 weeks after surgery.MAIN OUTCOME MEASURES: Changes of the host bone and the new bone formation in each group at various time points after operation.RESULTS: All 45 mature Chinese sheep were involved in the final analysis without any loss. Changes of the host bone and the new bone formation in each group at various time points after operation: ① Unaugmentation group: By 3 weeks after surgery, the thin fibrous tissue was found around the screw, and the host bone had micro-destruction. By 6 or 12 weeks after surgery, the micro-destruction of host bone was repaired. ② CPC augmentation group: By 3, 6 or 12 weeks after surgery, the most of gap between the screw and the host bone was occupied by this material, and the new bone connected directly to the material surface, and there was no intervening fibrous tissue between new bone and the material. Especially by 12weeks after surgery, a large quantity of the new bone was formed, and new bone was matured with many bone canals. ③ PMMA augmentation group:By 3 weeks after surgery, the thick fibrous tissue Between PMMA bone cement and the host bone, and the remarkable bone atrophy of host bone were found. By 6,12 weeks after surgery, the fibrous tissue and the bone atrophy were developed.CONCLUSION: CPC provide long-term beneficial augmentation of femoral neck fractures in sheep because of a good biocompatibility, good osteoconduction and capability of remodeling.

Effects of mitogen-activated protein kinase p38 on CD3/CD28-stimulated T-cell proliferation and IL-2 expression enhauced by shockwaves / 吉林大学学报(医学版)

Objective To investigate the effects of mitogen-activated protein kinase p38(p38 MAPK)on CD3/CD28-stimulated T-cell proliferation and IL-2 expression which were enhanced by shockwaves.Methods Jurkat T cells or peripheral blood mononuclear cells(PBMC)were pretreated with the p38 MAPK-inhibitor(SB203580)(The Jurkat T cells or PBMC of the control groups were not pretreated with SB203580),then treated with shockwaves,and stimulated respectively with a suboptimal dose of anti-CD3 and anti-CD28 antibodies or PHA.Finally the IL-2 productions of Jurkat T cells or the proliferation of PBMC were respectively measured.The protein tyrosine phosphorylation of p38 MAPKin Jurkat T cells treated either with shockwaves or not was measured by Western blotting with anti-phosphotyrine antibodies(Thr180/Tyr182).The expressoins of p38 MAPK in Jurkat T cells treated either with shockwaves or not were determined by Western blotting with anti-p38 MAPK antibodies.Results Compared with negative control group without shockwave treatment,the 3H-TdR incorporation of the phytohemagglutinin-stimulated PBMC,which were treated with low dose shockwaves(LDSWs)of 100,150,200,250,300,330 impulses at(0.180?0.015)mJ?mm2,increased significantly(P

A novel orthopaedic biodegradable polymer and its biocompatibility / 生物医学工程学杂志

Copolymer of polycaprolactone (PCL) and polylactic acid (PLA) was synthesized and catalyzed using Y (CF3COO)3/AL (I-Bu)3. The biocompatibility was evaluated by means of biochemistry, immunocytochemistry, and by cytotoxity test. This novel orthopedic biodegradable polymer can serve as an ideal orthopedic biodegradable implants, and adjustment of molecular weight and ratio of polymers can control its degradation period.

Experimental study on mechanical and biomechanical reconstruction of bone defect of long bone near joint / 中国组织工程研究

BACKGROUND:The repairing of bone defect near joint in long bone resulting from complicated comminuted fracture or excision of bone tumor is very difficult. It is a much studied issue to find a feasible solution to this problem.OBJECTIVE: To explore a feasible treatment to bone defect near joint in long bone through comparative observation of 3 reconstruction methods.DESIGN: A completely randomized experiment with self-control and mutual control.SETTING: Laboratory for Experimental Animals, First Hospital of Jilin University.MATERIALS: Twelve healthy adult hybrid dogs, 5 males and 7 females weighing 12 to 18 kg, were recruited.METHODS: The bone defects near joints were established in upper femoral condyle in the 12 dogs, which were reconstructed by 3 operation styles: only filling with bone cement, filling with bone cement + autogenous ilium bone graft, and filling with bone cement + autogenous ilium bone graft + fixation with L-trapezoid compression plate. There was one dog in each method. The specimens were harvested at the end of weeks 3, 6, 12and 24, respectively, after operation. One week before specimens were harvested the fluorescent labeling was prepared; we conducted vascular perfusion of disulphine blue before the animals were executed.MAIN OUTCOME MEASURES: A series of examinations were carried out, including X-ray film, biomechanical test, intravascular perfusion and tetracycline fluorescent labeling. The bone healing, blood supply recovery and biomechanics were observed in the three groups.RESULTS: The 12 dogs all entered the result analysis. ① Results of Xray examination: Two cases of fracture occurred in experimental side at 6and 12 weeks in group Ⅰ; one case of fracture occurred in experimental side at 6 weeks in group Ⅱ. No fracture happened in group Ⅲ. ② Bone stiffness assayed with biomechanics: It decreased in experimental side as compared to control side by 67% and 70% in group Ⅰ; 66%, 76% and 46% in group Ⅱ; and 8% in group Ⅲ. ③ Specimen observation after operation: Bone formation, callus, and blood supply recovery were significantly better in group Ⅲ than in groups Ⅰ and Ⅱ at all stages.CONCLUSION: The third operation, filling with bone cement + autogenous ilium bone graft + fixation with L-trapezoid compression plate, is an ideal method of bone reconstruction. It can recover bone function, and prevent complications such as refracture and bone nonunion.

The influence of biodegradable polymer on bone and soft tissue / 生物医学工程学杂志

Clinical and research reports concerning orthopedic biodegradable implants were reviewed. The clinical results were analyzed in terms of complications and compatibility. The possible applications of the implants and further research fields were summarized.

New concepts for treatment of osteoporosis complicated with fracture / 中华创伤骨科杂志

Osteoporosis complicated with fracture is a common and severe condition. This paper summarizes present advances and new concepts in its treatment. Since the secondary osteoporosis will likely develop after fracture treatment with immobilization, more and more bone mass will get lost in addition to primary osteoporosis. A vicious cycle will be established and influence the fracture healing. Therefore, the key to the treatment is to block the vicious cycle to stop or decrease the bone loss. As a routine measure, to do exercises and weight- bearing activities as early as possible is as important as to take medicines for osteoporosis treatment. Stable internal fixation and prosthetic replacement should be firstly chosen for treatment of most fractures. In drug treatment, calcitonin, bisphosphonate (alendronate), HRT (Livial), vitamins D2 and D3, and calcium are indicated.

Construction of guided bone regeneration membrane by tissue engineering in vitro / 生物医学工程学杂志

In this study, porous polymer (PLA/PCL) membrane was first treated with ethanol to become hydrophilic, and then immersed into DMEM with 50% fetal bovine serum to enhance the affinity to cells. MSCs cultured in osteogenic medium were loaded into the membrane at density of 5 x 10(6)/cm2 for 7 days, and scanning electrical microscope was used to observe the growth of the MSCs. The growth of MSCs inside the constructs was functionally well, and the cells proliferated with the time of culture. We concluded from current study that the membrane had satisfactory biocompatibility and the constructs could be used to guided bone regeneration.

Prosthetic replacement in treatment of subcapital femoral neck fractures in the elderly / 中华创伤杂志(英文版)

<p><b>OBJECTIVE</b>To compare the results of femoral head replacement (FHR) and total hip replacement (THR) in treatment of subcapital femoral neck fractures (SFNF).</p><p><b>METHODS</b>Between May 1987 and July 1998, 56 elderly patients (6 5-90 years; average 73.5 years) with SFNF were treated with prosthetic replacement. Six cases were treated with unipolar FHR, 18 cases with Bateman bipolar FHR, and 32 cases with Bateman bipolar THR. All domestic prostheses were installed with cement.</p><p><b>RESULTS</b>There was no significant difference between the 2 groups in operating time and blood transfusion. Forty-nine patients were followed-up for an average of 5 years and 10 months. No wound infection or death was related to surgery. Complications in Group FHR were significantly higher than that i n Group THR.</p><p><b>CONCLUSIONS</b>Since FHR is difficult to fit the bony acetabulum, it is only indicated for senile cases with poor conditions. However, the bi polar THR installed with cement is indicated for most elderly patients. Since th e femoral head and acetabulum can fit each other completely, it is more stable for taking weight-bearing earlier with less complications.</p>

Experimental study on properties of stress-relaxation of the middle and lower cervical spine / 中华创伤骨科杂志

Objective To study the properties of stress relaxation of the middle and lower cervical vertebrae, and to evaluate the effects of laminotomy and anterior diskectomy and spinal fusion (ASF) on the properties . Methods The dynamic responses of stress relaxation of six intact and post operative fresh human cadaveric cervical vertebrae were measured in vitro. Results Under the condition of the constant strain, the functional equations and the curves of stress relaxation of the six intact and post operative fresh human cadaveric cervical vertebrae were obtained. The Gex(t)(the ratio of the ensuing instant stress to the original stress) of the post operative ones was significantly bigger than that of the intact ones; The Gex(t) of the laminotomic ones was significantly bigger than that of the ones having undergone the anterior discectomy and spinal fusion(ASF). Conclusion Either in flexion or in extension, cervical vertebrae have the similar behaviors of stress relaxation. The laminotomy and anterior discectomy and spinal fusion (ASF) all reduce the stress relaxation effect of the cervical vertebrae, but ASF is more significant.

An in vivo experimental implantation of four kinds of treated prosthetic surface / 中华骨科杂志

Objective To promote the clinical practice of bone morphogenetic proteins (BMP) coated prosthesis in order to improve its biological fixation. Methods There were 12 healthy mongrels, weighted from 20 to 25 kg. They were randomly divided into 3 groups according to the scarified time. The bilateral femurs were adopted as the graft areas, and 4 kinds of implant were transplanted into each femur randomly. The transplant consisted of porous-coated anatomic(PCA group), PCA combined with BMP (BMP group), PCA combined with hydroxyapatite(Composite group), and polish PCA combined with HA (HA group). The femurs of the mongrels were retrieved at the 4th, 8th and 12th week respectively. Bone ingrowth and shear strength between the interfaces of the bone-implant were studied, using X-ray, soft X-ray, fluorescence tag, non-decalcification ground section, computer-aided image analysis, and histological examinations. Results By gross observation, the composite for the group of PCA with BMP was the most stable in all the experimental groups. All implants showed good histocompatibility, the bone ingrowth on the implant surface appeared earlier in the BMP group than any others, and so did the maturation of new bone. At 4th week, the percent of new bone formation in the BMP group was 26.58%?4.56%, which was also much higher than PCA group (18.28%?2.46%), Composite group (17.23%?2.11%), and HA group(16.89%?3.13%) through the means of non-decalcified ground section and computer aided image analysis, and the difference was of statistical significance(P0.05). Conclusion The composite of BMP to the PCA is effective and feasible procedure, which could increase biological fixation of the interfaces between the bone and implant. Furthermore, HA coating is also an effective method of prosthesis surface treatment in order to improve bone ingrowth and enhance the interface shear strength, and the technique of HA coating is an essential factor in processing the prosthesis.

THE PRIMARY STUDY ON RABBIT BONE MARROW MESENCHYMAL STEM CELLS IN CONSTRUCTING TISSUE-ENGINEERED CARTILAGE / 中国修复重建外科杂志

Objective　To study the feasibility of constructing tissue engineered cartilage by differentiated rabbit bone marrow mesenchymal stem cells(MSC) cultured in vitro and in vivo. Methods　The MSC were isolated from the nucleated cells fraction of autologous bone marrow by density gradient centrifuge, and then induced into chondrogenic differentiation by adding dexamethasone, transforming growth factor-β1(TGF-β1) and ascorbic acid in vitro. After 3 weeks, some cells turned to round shape and secreted metachromatic matrix. The cartilaginoid grafts composed of chondrogenic MSC. Bovine type Ⅰ collagen and human fibrin were cultured within the chondrogenic medium for 2 weeks in vitro or transplanted subcutaneously adjacent to the knee joint for 3 weeks in vivo. Results　The most cells in the grafts were degenerated and disappeared after cultured in vitro. But the residual cells were survival and secreted metachromatic staining proteoglycan with toluidine blue, which was characteristic cartilage matrix. The grafts developed into matured cartilage tissue assessed by histological examination after 3 weeks of transplantation in vivo. Conclusion　MSC can be used as functional cells to constructing tissue engineered cartilage.

Ultrastructure changes of osteosarcoma cells inactivated by alcohol in different concentrations / 吉林大学学报(医学版)

Objective：To study the ultrastructure changes of osteosarcoma cells(OS-732) inactivated by alcohol of two different concentrations and clinical application value.Methods：Osteosarcoma cells(OS-732) were inactivated by 75% and 95% alcohol and observed by light and electron microscope.And its viability was detected by MTT method. Results：Cell internal structure changed significantly and irreversible damage formed. MTT method proved that inactivated cells had no viability.Conclusion：These two inactivation methods were effective. Cell internal enviroment was damaged very seriously and cell was led to death. These two inactivation methods could provide choices for clinical limb protective operation.

Repair of articular cartilage defects with tissue-engineered cartilaginous grafts in rabbits / 中华创伤杂志

Objective　To observe the effect of repairing the articular cartilage defects with tissue-engineered cartilaginous grafts in rabbits. 　Methods　 A total of 60 rabbits were divided into the cartilage graft group, the pure carrier control group and the blank control group. In the cartilage graft group, the bone marrow mesenchymal stem cells (MSCs) of the rabbits were obtained by isolating and culturing the bone marrow aspirates in vitro. The culture system that facilitates the chondrogenous differentiation of MSCs in rabbits was established. The tissue engineering cartilaginous graft was composed of chondrogenetic MSCs, bovine type Ⅰ collagen and human fibrin. Then transplantations of the cartilaginous grafts were performed to repair articular cartilage defects in rabbits. 　Results　Hyaloid cartilage was formed within the defects repaired with the grafts at 12 weeks after transplantation by analyzing the content of type Ⅱ collagen and metachromatism. In the control groups, the fibrous cartilage repair was observed first, then the fibrous tissues and bone repairs were found. 　Conclusions　 The cartilaginous graft through tissue engineering is a promising graft for repairing articular cartilage defects.

Treatment of intertrochanteric fractures of the femur with L-trapezoid compression plate and its mechanical principles / 中华创伤杂志(英文版)

OBJECTIVE: To improve the results of the treatment of unstable types of intertrochanteric fractures of the femur (ITFF) by internal fixation. METHODS: A L-trapezoid compression plate system (L-TCP) was designed and compared to the AO/ASIF angle plates of 95 and 130 (L-AP) with mechanical tests. An Evans Type III model was made, the simulation electrical test with loading on single and both legs were done. The results demonstrated that the stability of the L-TCP fixation was significantly greater, and the stress concentration at the upper screw hole was relevantly smaller than that of L-AP. From June 1986 to June 1998, 82 patients of ITFF were treated with L-TCP fixation. The average age was 67.4 years old (26-91). Seventy-four of those fractures were unstable. Fifty-eight patients were treated with open reduction, and 24 cases were treated by closed reduction and limited open (only lateral aspect of upper femur was exposed) fixation with L-TCP under X-ray monitoring. RESULTS: Sixty-six patients were followed up for 6-69 months. Complications, including 3 wound infection, 1 non-union, 3 coxa varus and 2 implant breakage (9 complications of 7 cases), all occurred in the open reduction group. No complication was found in the closed reduction group. CONCLUSIONS: In the treatment of ITFF, the results of closed reduction and limited open fixation with L-TCP is significantly better than that of open reduction and fully exposed fixation.