Three dimensional induction of autologous mesenchymal stem cell and the effects on depressing long-term degeneration of tissue-engineering cartilage / 中华外科杂志

<p><b>OBJECTIVES</b>To induce autologous bone marrow derived mesenchymal stem cell (aMSC) into chondrocyte, and to confirm the effects of 3 dimensional (3D) dynamic inducing in vitro and their long-term animal model repairing in vivo.</p><p><b>METHODS</b>aMSC were separated from rabbits bone marrow aspirates, then respectively experienced 3D dynamic inducing in alginate drops in modified rotating wall bioreactor culture or in two dimensional (2D) inducing (culture flask) for 10 d. The induced cells were harvest and then mixed with fibrin sealant (FS) to repair rabbit knee femoral trochlea cartilage defects model. After 8, 12, 24, 48 weeks animals were euthanized. Gross appearance, histological appearances were examined.</p><p><b>RESULTS</b>Flask culture groups showed a little chondrocyte differentiation, 3D inducing group showed obviously chondrocyte differentiation, improved collagen II and proteoglycan production. For 3D inducing ones in vivo, the cartilage defects were smoothly repaired by white translucent hard tissue with obvious hyaline-like cartilage histological appearance after 8, 12 weeks, and the defects boundary were hard to be identified with hyaline like cartilage with sustained histological appearance and score after 24, 48 weeks. For 2D ones in vivo, the cartilage defects were smoothly repaired after 8 weeks by hyaline like cartilage which showed accelerated degeneration after 24 weeks and lose cartilage performance completely after 48 weeks.</p><p><b>CONCLUSIONS</b>3D dynamic inducing may assist aMSC on differentiating into chondrocyte, improve its long-term in vivo repairing effects, and enlighten its further applications in tissue engineering cartilage.</p>

Morphology research of the rat sciatic nerve bridged by collage-heparin sulfate scaffold / 中华外科杂志

<p><b>OBJECTIVE</b>To observe the treating effect of collage-heparin sulfate after the 10 mm rat sciatic nerve defect was bridged by it.</p><p><b>METHODS</b>A new kind of nervous tissue engineering scaffold was produced by freeze-drying technique from collagen-heparin sulfate. Thirty-two SD rats were randomly divided into A, B, C and D groups. Sciatic nerve defect in group A was bridged by collagen-heparin sulfate. In group B, sciatic nerve was bridged by auto-nerve transplantation. Group C was the blank control group. Animals in group D were normal. And 10 mm sciatic nerve defect was bridged in the experiment. Thirty-six weeks after the operation, the experimental animals were detected by HRP labeled retrograde trace, HE staining, toluidine staining, silvering staining, S100, GAP-43 and NF immunohistological staining, MBP immunofluorescence staining and transmission electron microscope to observe the nerve regeneration inducing effect of this new scaffold.</p><p><b>RESULTS</b>Nine months after operation, the collage-heparin sulfate scaffold was replaced by newly regenerated nerve. The number of HRP labeled spinal cord anterior horn cells and the area of sensation nerve fiber at the posterior horn were similar with that was repaired by auto-nerve. GAP-43, NF and S100 labeled regenerated nerve fiber had passed the total scaffold and entered the distal terminal. The regenerated nerve fibers were paralleled, lineage arranged, coincide with the prearranged regenerating "channel" in the collagen-heparin sulfate scaffold. MBP immunofluorescence staining also proved that the newly regenerated nerve fiber could be ensheathed. In the experimental group, the area of myelinated nerve fiber and the thickness of the myelin sheath had no obvious difference with that of the group repaired by auto-nerve, except that the density of the regenerated myelinated sheath fiber was lower than that of the control group.</p><p><b>CONCLUSION</b>Nervous tissue engineering scaffold produced by collagen-heparin sulfate can guide the regeneration of nerve fibers. The nerve function recovers fine. This kind of material has great application potential.</p>

Reciprocal action between BMP-2 and BMP-3 in cultured fibroblast in vitro / 中华创伤杂志(英文版)

<p><b>OBJECTIVE</b>To explore reciprocal action between BMP-2 (bone morphogenetic protein-2) and BMP-3 for better understanding of the mechanism of BMP during bone fracture union.</p><p><b>METHODS</b>rhBMP-2 was added into the cultured fibroblasts with the concentration of 1,200 ng/ml. The expression of BMP-3 in fibroblasts was detected by immunohistochemistry. Eukaryotic expression vector pcDNA3-BMP-3 was transfected into the fibroblasts. After the effective expression of BMP-3 was identified, BMP-2 was also detected by immunohistochemistry in BMP-3 expression cells. The fibroblasts transfected with empty vector pcDNA3 were used as the control.</p><p><b>RESULTS</b>Exogenous rhBMP-2 could promote the expression of BMP-3 in fibroblasts. BMP-3 also could be detected in these cells.</p><p><b>CONCLUSIONS</b>BMP-2 and BMP-3 could reciprocally adjust the expression in fibroblasts.</p>

Treatment of tibial defect and bone nonunion with limb shortening with external fixator and reconstituted bone xenograft / 中华创伤杂志(英文版)

<p><b>OBJECTIVE</b>To explore the effect of external fixator and reconstituted bone xenograft (RBX) in the treatment of tibial bone defect, tibial bone nonunion and congenital pseudarthrosis of the tibia with limb shortening.</p><p><b>METHODS</b>Twenty patients (13 males and 7 females) with tibial bone defect, tibial bone nonunion or congenital pseudarthrosis of the tibia with limb shortening were treated with external fixation. Two kinds of external fixators were used: a half ring sulcated external fixator used in 13 patients and a combined external fixator in 7 patients. Foot-drop was corrected at the same time with external fixation in 4 patients. The shortened length of the tibia was in the range of 2-9 cm, with an average of 4.8 cm. For bone grafting, RBX was used in 12 patients, autogenous ilium was used in 3 patients and autogenous fibula was implanted as a bone plug into the medullary canal in 1 case, and no bone graft was used in 4 patients.</p><p><b>RESULTS</b>All the 20 patients were followed-up for 8 months to 7 years, averaging 51 months. Satisfactory function of the affected extremities was obtained. All the shortened extremities were lengthened to the expected length. For all the lengthening area and the fracture sites, bone union was obtained at the last. The average healing time of 12 patients treated with RBX was 4.8 months.</p><p><b>CONCLUSIONS</b>Both the half ring sulcated external fixator and the combined external fixator have the advantages of small trauma, simple operation, elastic fixation without stress shielding and non-limitation from local soft tissue conditions, and there is satisfactory functional recovery of affected extremities in the treatment of tibial bone defects, tibial bone nonunion and congenital pseudarthrosis of the tibia combined with limb shortening. RBX has good biocompatibility and does not cause immunological rejections. It can also be safely used in treatment of bone nonunion and has reliable effect to promote bone healing.</p>

Biomechanic results of PLGA/TCP scaffold with bovine BMP in treating peri-porous-titanium bone defects in femur of adult rabbits / 中华创伤杂志

Objective To evaluate the feasibility of composite material of bone morphogenetic protein (BMP) and PLGA/TCP in repair of peri-porous-titanium bone defects in adult rabbits.Meth- otis The composite of PLGA/TCP scaffold with bovine BMP was made and implanted in distal bone de- fects peri-porous-titanium in femur of adult rabbits.The effect of BMP with PLGA/TCP on peri-prosthesis was evaluated by means of scanning electron microscope (SEM),energy dispersive X-ray analysis (EDX) and biomechanics.Results BMP with PLGA/TCP showed obvious peak of Ca and P of EDX in the pores of titanium in experiment group six weeks after operation and higher than that in control group (P＜0.05).Push-out test demonstrated that the bonding strength between the composite of HA coating/ porous titanium and bone was increased significantly with time (P＜0.05).In experiment group,at 6 and 12 weeks,peri-porous-titanium had higher shearing force compared with control group (P＜0.05). Conclusion BMP loaded with PLGA/TCP is a promising bone graft for bone defects in revision arthro- plasty,as indicates that bone induction of BMP plays an important role in biological stabilizaiton.