Objective　To prevent early closure of growth plate and developmental deformities of limbs by allografts of cultured cartilages into growth plate defects of rabbits. Methods　Chondrocytes isolated from articular cartilage of 1-month rabbits formed cartilage after cultivation in centrifuge tubes. The cartilages cultured for two weeks were implanted into growth plate defects of proximal tibiae of 6-weeks rabbits. At 4th and 16th weeks, X-ray, histologic and immunohistochemical examination were performed. Results　The tibiae had no marked deformities after 4 weeks of operation. Histologic examinations showed that the defects were filled with cartilage. Immunohistochemical results of type Ⅱ collagen were positive. The tibiae with allografts of cultured cartilages had no evident deformities after 16 weeks of operation. Histologic examination showed nearly closure of growth plates. On the contrary, the tibiae on control side formed severe deformities and growth plate were closed. Conclusion　Allograft of cultured cartilages into growth plate defects may replace lost growth plate tissues, maintain normal growth of limbs and prevent developmental deformity.

Objective To investigate the ability of osteogenesis, repaired effects and possible mechanism of tissue engineered bone made in an approach of bionics as a transplantation biomaterial to repair a segmental defect of long bone. Methods HA/?-TCP was composed with PDLLA and then composed with rhBMP-2 and collagen of typeⅠ. The combined biomaterial was put in common culture with osteoblasts harvested from periosteum of rabbit and vascular endothelial cells from kidney of rabbit then transplanted this tissue engineered bone to total segmental periosteum-bone defect of 1.5 cm in the rabbits radius which were investigated 4, 8 and 12 weeks after operation respectively. Investigation of the bone defect was made by means of gross observation, X-ray examination, histology of HE and Masson staining, image pattern analysis, scanning electron microscopy, EDAX. Results In gross observation, the implantations were adhered to the host bone well in four weeks, the implantations was bony healed with host bone in eight weeks, and some of the implantations were replaced by new formation bone in 12 weeks. In histological examination of four weeks after operation, lamellar bone was found, and eight weeks after operation, implant was incorporated to host bone end by end through cortical bone, and new bone marrow was found to invade into the implant. Furthermore, the outer part of implant was completely substituted by new cortical bone 12 weeks after operation. In addition, the histological study pointed out that the new bone arranged in type of various bands which were in subsequent transition. There is significant difference between 4 weeks and 8 weeks, and 4 weeks and 12 weeks, but no significant difference between 8 weeks and 12 weeks of the quantity of new bone. The ratio of calcium to phosphorus in the transplants tended to approach that in the host cortical bone along with the period of time after operation. Conclusion Satisfied effects of remodeling appeared after this tissue engineered bone composed by bionics was transplanted to the segmental defect of long bone. The mechanism of bone regeneration was endochondral ossification.

Objective To explore the medical ethical problens in the research of tissue engineering and their clinical application.Methods According to the technical route of tissue engineering ,including seeding cells.scaffold materials,implantation in body,ethical problems and their disposal were dissussed.Results Patient's rights to know the facts of test,efficacy and security of clinical application must be fully ensured during implantation of seeding cells and scaffold materials to human body.Conclusion In needs to formulate related standard of tissue engineered products and perfect politics and regulations.

Objective To review and summarize the latest development of the therapy for the Duchenne muscular dystrophy (DMD). Methods The recently-published articles related to the therapies for DMD were extensively reviewed and briefly summarized. Results The therapeutic approaches for DMD included the gene therapy, the cell therapy, and the pharmacological therapy.The gene therapy and the cell therapy were focused on the treatment for the cause of DMD by the delivery of the missing gene, the modification of the mutated gene, and the transfer of the normal cells including the stem cells, while the pharmacological therapy dealt with the downstream events caused by the dystrophin gene defect, slowed down the pathologic progress of DMD, and improved the DMD patient's life quality and life span, by medication and other factor treatments. Conclusion There is still no cure for DMD because of various difficulties in replacing or repairing the defected gene and of the multifaceted nature of the severe symptoms. Therefore, it is imperative for us to find out a more effective treatment that can solve these problems.

0.05),hints that the tenocyte's function was not disturbed. The DNA index of cells of GDBM group was 0.96 and 2.1% higher than the control group,indicating that the tenocytes grow and proliferate faster when being combine cultured on GDBM. Conclusion GDBM show good biocompatibility combined with tenocytes and they are promising extracellular matrix scaffold for cell transplantation in tendon tissue engineering.

ObjectiveTo study the variant differentiated phase of the human bone marrow stromal cell (MSC) during induced adipogenesis course by morphological observation.MethodsAfter proliferated in vitro, MSCs isolated from bone marrow of the female adults volunteers were cultured with the adipogenetic inducers for 6—30 days. Morphological changes of the cells were observed everyday under Olympus contrast phase microscopy, and some specimens were stained with Oil-red-O.ResultsMSC showed long spindle shape before inducing, and then changed gradually to oval or round shape and the figure enlarged simultaneously. There were specifically morphological changes with lipid droplet emergence under plasmalemma and confluence gradually to lipid drop during differentiated into the phase of immature and mature adipocyte.ConclusionIt is easy to detect the MSC differentiated into the phase of immature and mature adipocyte with the specific morphological change of lipid droplet, while in the phase of preadipocyte and adipoblast, there is no special morphological change, and it may need some specific markers to detect.

This study was conducted to investigate the biomechannical properties of tissue-engineering cartilage. The compressive modulus of the collagen-chondrocyte constructs that had been cultured in vivo for 16 weeks and the centrifuge-tube-cultured cartilage in vitro were measured with 5% strain. The results showed that the compressive moduli of the centrifuge-tube-cultured cartilage at the 4th, 8th, 12th and 16th weeks were 0.352MPa, 0.653MPa,0.233MPa and 0.262MPa respectively. The top modulus among them was at the 8th week. The compressive modulus of the neocartilage engineered by the collagen-chondrocyte constructs in vivo for 16 weeks was 10.668 MPa and reached the same order of magnitude as human fetal articular cartilage, but it is still under that of the human fetal articular cartilage actually. The culture methods should be developed further though the dynamic alteration of the compressive modulus of the centrifuge-tube-cultured neocartilage is in accord with that of the GAG/DNA content ratio of the neocartilage.

To detect the properties of natural xenogeneic bone derived materials which were processed with different physical and chemical treatments, we made fully deproteinized bone(FDB), partially deproteinized bone (PDPB), partially decalcified bone(PDCB) from pig ribs. Their morphological features, constitute components and mechanical properties were examined by scanning electron microscopy, x-rays diffraction analysis, mechanical assay and so on. The results showed that FDB, PDPB and PDCB maintained natural network pore system. The ratios of calcium to phosphorus were 1.81, 1.74 and 1.50, and the protein contents were 0.01% +/- 0.02%, 22.41% +/- 0.83% and 35.75% +/- 2.12% respectively. The sequence of their mechanic strength was PDCB > PDPB > FDB. These data indicate that FDB, PDPB and PDCB possess natural network pore system. Their organic and inorganic component ratios and contents are different, so their mechanic properties are not alike. Additionally, more investigations will be necessary to detect the biocompatibility of the three different scaffold materials of natural derived bone.
Animals ; Biocompatible Materials ; chemistry ; Biomechanical Phenomena ; Bone and Bones ; chemistry ; Materials Testing ; Swine ; Tissue Engineering

This study sought to find out a good way for the cryopreservation of tendon seeding cells so as to facilitate the preparation of tissue engineering tendons as products. The related questions are how different factors affect cell survival rate at the procedure of preservation and whether cryopreservation affects seeding cells' biological characters as well as collagen secretive function. The results of experiment indicate that DMSO is a more effective cryoprotectant in cryopreservation of tissue engineered tendon seeding cells. Blood serum nourishment is very important in cell culture, preservation and treatment. The same sustenance after cryopreservation increases cell survival rate. In the process of cryopreservation, the concentration of cells is important to cell survival rate; cell survival rate will decrease when it is less than 1.0 x 10(6)/ml. In the process of cryopreservation, the cooling speed is also important to cell survival rate, slow cooling method achieves higher cell survival rate than does the rapid cooling method. Cryopreservation by use of 10%DMSO+15%FCS+75%DMEM does not affect seeding cells' collagen secretive function greatly and does not affect seeding cells' growth curve, cell cycle and chromosome mode obviously. The prescription of 10%DMSO +15%FCS+75%DMEM is suited for the cryopreservation of tendon seeding cells.
Cell Count ; Cell Survival ; Cryopreservation ; methods ; Dimethyl Sulfoxide ; Humans ; Muscle, Skeletal ; cytology ; Tendons ; cytology ; Tissue Engineering ; Tissue Preservation ; methods

This article introduces a three-dimensional scaffold which is used to perform three-dimensional cell culture under mechanical stretch from the point of construction of tissue-engineered tissue. The composition, structure, surface characteristics, mechanical property, and cell compatibility of the scaffold have been studied by using surface chemistry and material mechanics testing methods. The results indicate that the polyvinyl alcohol (PVA) sponge, which is water-tolerant, coated with Poly-DL-lactic-co-glycolic acid (PLGA) possesses a good nature in appropriate surface feature, porosity, elastic recoil, and cell compatibility. These features provide wide options for using this scaffold to study the effects of mechanical stretch on cells maintained in three-dimensional culture to provide a three-dimensional matrix.
Biocompatible Materials ; Biomechanical Phenomena ; Cell Culture Techniques ; Humans ; Lactic Acid ; Polyglycolic Acid ; Polymers ; Polyvinyl Alcohol ; Surface Properties ; Tendons ; cytology ; Tissue Engineering