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 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.

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.

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.

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.

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 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

In this study we examined the in vitro characteristics of tenocyte adhesion to biologically-modified surface of polymer. Polylactic-co-glycolic acid (PLGA) 85/15 films were prepared by a solvent-casting technique. Each film was adhered onto the bottom of a chamber. The film was precoated with poly-D-lysine (PDL), and then coated with serum-free F12 medium containing various concentrations of fibronectin (FN), type I collagen (CN I), and insulin-like growth factor1 (IGF-1). The monoclonal antibodies (to FN and to CN I) with various dilutions were used to inhibit attachment of tenocytes to surface precoated with FN or CN I. Human embryonic tendon cells (HETCs) and transformed human embryonic tendon cells (THETCs) were used as the seeding cells. The system used for the measurement of adhesion force was the micropipette aspiration experiment system. The micropipette was manipulated to aspirate a small portion of the tenocyte body by using a small aspiration pressure. Then the pipette was pulled away from the adhesion area by micromanipulation. The minimum force required to detach the tenocyte from the substrate was defined as the adhesion force. The results showed that modification of FN or CN I by precoating significantly enhanced attachment of tenocytes to surface of polymer (P < 0.05). As antibodies to FN or CN I were added to a polymer film precoated with FN or CN I, the adhesion force decreased significantly (P < 0.05). We concluded that the specific adhesion forces of tenocytes to extracellular matrix adhesion proteins (FN and CN I) had coordinated action and showed good dependence on their precoating concentrations, and were inhibited by the antibodies to these adhesion proteins. Films precoated with IGF-1 strongly accelerated the adhesion of tenocytes to polymer. These results indicate that the specific adhesion of tenocytes to polymer can be promoted by coating extracellular matrix adhesive proteins and insulin-like growth factor1. It is of great importance to construct tissue-engineered tendon.
Biocompatible Materials ; chemistry ; Cell Adhesion ; drug effects ; physiology ; Cells, Cultured ; Extracellular Matrix Proteins ; pharmacology ; Growth Substances ; pharmacology ; Humans ; Lactic Acid ; chemistry ; Polyglycolic Acid ; chemistry ; Polylysine ; pharmacology ; Polymers ; chemistry ; Tendons ; cytology ; embryology ; physiology ; Tissue Engineering

OBJECTIVETo study the histocompatibility of three bio-derived bones.

METHODSAfter treatment with different physical and chemical method, three bio-derived bones, the composite fully deproteinized bone (CFDB), partially deproteinized bone (PDPB) and partially decalcified bone (PDCB) were implanted into rabbits. The toxicity, immune response and subperiosteum osteogenesis of CFDB, PDPB and PDCB were studied through gross observation, serum antibody measurement, evaluation of local cellular immune response and HE staining.

RESULTSThe study showed that CFDB, PDPB and PDCB had no toxicity. They could conduct peripheral tissue to grow into them and had no harmful effect on subperiosteum osteogenesis. They could also promote cartilage and osteoid tissue derived from periosteum to calcify to new bone, and combine with the peripheral bone. The degree of immune response caused by them was in the sequence of PDCB > PDPB > CFDB.

CONCLUSIONSThe three bio-derived bones, CFDB, PDPB and PDCB have good histocompatibility.

Animals ; Antibodies ; blood ; Bone Transplantation ; Bone and Bones ; immunology ; Female ; Histocompatibility ; Histocompatibility Testing ; Male ; Rabbits ; Tissue Engineering