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.

This experiment is sought to study the contribution of different gene in osteogenous differentiation of bone marrow stromal cells (MSCs) and optimize the seed cells of bone tissue engineering. Firstly, we obtained the full length gene of BMP-2, VEGF165 and bFGF by RT-PCR, and cloned into the expression vector pcDNA3. 0. After to be transfected, the MSCs cell lines which could express each of the target protein were selected out by G418. RT-PCR and immunohistochemistry were used to confirm the exogenous gene expression in MSCs. MTT showed that almost all of the MSCs which have been transfected with exogenous gene had more strong proliferative potential than the untransfected group did. There was a notable increase of ALP activity in transfected cell compared with the control group. The concentration of OCN in cell culture medium had a increase in some degree except of VEGF group. The outstanding osteogenous differentiation could be observed in BMP-2 and bFGF transfected MSCs. The results showed that the MSCs modified by BMP-2 and bFGF would be more effective in bone tissue engineering field.

When the size of a neurosphere cultured in vitro reaches a certain critical value, a necrotic core will appear inside the neurosphere because of the limitation of oxygen or other nutrients transport from medium to the cells in the neurasphere. Large necrotic core will greatly reduce the expansion of NSCs. The cellular automaton (CA) model is applied in this article to model the growth of NSCs in sphere state. The appearance and enlargement of the necrotic core in a neurosphere is calculated by coupling the CA model with the nutrient diffusion analysis in bioreactors. The calculation results indicate that the culture conditions, such as seeding density, the concentration of nutrients in medium and the mass transfer coefficient between a neurosphere and medium, have some effects on the appearance of the necrotic core. However, the necrotic core mainly depends on the inner diffusion. It will certainly appear if the size of the neurosphere is large enough even the outside mass transfer is in a good condition in bioreactors. Additionally, the appearance of the necrotic core resulting from the shortage of oxygen is earlier than that caused by the limitation of glucose. And the growth of the necrotic core is very fast after its appearance, and the whole neurosphere may become necrotic. The model developed with cellular automaton and mass transfer is a good qualitative representation of NSCs growth in bioreactors.

To investigate the growth and osteogenesis characteristics of cultured canine mesenchymal stem cells (cMSCs) under osteogenic induction. We found the cMSCs were isolated from adult canine using density gradient separation method. The cMSCs attachment formed soon after seeding and grew into colonies with the appearance of fibroblastic cells. The osteogenic induction compound of Dexamethasone (Dex), beta-sodium glycerphosphate (beta-GP), ascorbic acid (AA) was added to passaged cMSCs and the proliferation and osteogenic differentiation of them was studied. The morphology of cells was observed by light micrograph and transmission electron microscope. The proliferation and growth characteristics of cMSCs were observed during primary and passage cultures through MTT. The differentiation were assayed by alkaline phophatase (ALP) and osteocalcin (OCN). We found the cMSCs have an active proliferative ability in primary and passage culture, and cMSCs under osteogenic induction have the typical characteristic of a secretory cell; the osteogenic induction compound may induce cMSCs to differentiate to osteoblasts. There are higher expression of ALP and OCN in passage 3 cMSCs under osteogenic induction than that of the osteoblasts osteogenic induction condition. Our research suggest the cMSCs in our culture system are mainly undifferentiated osteoprogenitors and can differentiate to osteoblast under osteogenic induction.

The purpose of this paper is to investigate the osteogenesis and adipogenesis in bone marrow mesenchymal stem cells (MSCs) isolated from normal rats and osteoporotic rats by ovariectomy. Osteoporotic animal model was established in 3 month-old and 6 month-old female Sprague-Dawley (SD) rats by ovariectomy. Animal experiments were divided into 4 groups: 1) control-3 group; 2) ovx-3 group; 3) control-6 group and 4) ovx-6 group. MSCs were isolated by means of the density-gradient centrifugation method from each group, respectively. Colony-forming unit-fibroblast (CFU-Fs ) number, CFU-Fs size distribution and cell density in CFU-Fs of primary passage MSCs were measured at the inverted phase contrast microscope. The cell cycle and proliferation index (PI) as well as apoptosis idex (AI) of MSCs were studied by (FCM). After osteogenic induction (OSI), calcium nodes of MSCs were marked by alizarin red staining (ARS); The expression level of alkaline phosphatase(ALP) was detected by dynamics method with substrate of phosphoric acid para-Nitro benzene and the content of osteocalcin (OCN) was detected with the isotope labelling method. After adipogenic induction (ADI), lipid droplet in MSCs were detected by oil red O staining and the mRNA level of lipoprotein lipase (LPL) was measured by RT-PCR. The results showed that CFU-Fs and PI are obviously decresed and AI are increased of MSCs in OVX-3 and OVX-6 groups (P<0.05). The secretory volume of ALP and BGP of MSCs and the content of calcium nods of MSCs are lower in OVX-3 and OVX-6 groups than that in control-3 and control-6 groups after osteogenic induction (P<0.05). The number of lipid droplet and the expression level of LPL mRNA are higher in OVX-3 and OVX-6 groups than that in control-3 and control-6 (P<0.05). The result in our study suggested that depress of osteogenesis and the up-regulation of adipogenesis of MSCs in osteoporotic rats by ovariectomy may be relate close to the pathogenesis of osteoporosis.

To summarize the developmental process of biomedical materials and regenerative medicine.

To establish a method of constructing skin-equivalents (SE) by the hair follicle stem cells (HFSC) and the fibroblasts.

To compare the reparative effects between the acellular small intestinal submucosa and the acellular amnion as dressings for traumatic skin defects.

To investigate the feasibility of the complex of the fibrin sealant (FS) and the bone marrow mesenchymal stem cells(MSCs) to create a new cartilage in the nude mice by the issue engineering technique.

To explore an experimental method of transfecting the marrow stromal stem cells (MSCs) with the reconstructed PGL3-transforming growth factor-beta1 (TGF-beta1) gene and to evaluate the feasibility of self-induction of MSCs to the chondrocytes in vitro so as to provide a scientific and experimental basis for a further "gene enhanced tissue engineering" research.

To find a new culture system to induce proliferation and osteodifferentiation of marrow stromal cells (MSCs) in vitro for bone tissue engineering.

To observe effects of the core binding factor alpha1 (Cbfalpha1) in its promoting differentiation of the rabbit marrow mesenchymal stem cells (MSCs) into osteoblasts.

To monitor the stem cell migration into the bone defect following an injection of the labeled mesenchymal stem cells (MSCs) by the enhanced green fluorescent protein (EGFP) technology and to provide insights into an application of MSCs for the fracture healing.

To investigate the source of the metaplasia chondrocytes in the bilaminar zone following anterior disc displacement (ADD) of temporomandibular joint (TMJ).

This study investigated the effect of hyperbaric oxygenation (HBO) on neural stem cells (NSCs) and myelin in neonatal rats following hypoxic-ischemic brain damage (HIBD) and aimed to explore the possible mechanism of the protective effect of HBO on HIBD.

Recent progress in developmental biology has shown that the thyroid transcription factor-1 (TTF-1) plays an important role in lung development. The aim of this study was to investigate the expression and distribution of TTF-1 and its function during the development of epithelial stem cells in fetal human lungs.

To investigate the changes in circulating bone marrow stem cells in pregnant rabbits after AMI (AMI) and their relationship with estradiol.

To obtain recombinant nestin and prepare anti-nestin polyclonal antibody (mAb) to explore the biological roles of nestin in the central nervous system development.

To investigate the mechanism of avian influenza outbreak wildly in water fowls, the co-pathogens, especially that caused immuno-depression were studied. A pair of degenerated primers, which amplified a fragment of 552bp in length, was designed and synthesized based on the published goose and other Circovirus sequences. The specific PCR product was amplified from the goose sample of Yongkang avian influenza case of Zhejiang Province. The fragment was then sequenced and the result showed the existence of the GoCV. The opposite part of the genome was further amplified using inverse primers designed based on the 552bp sequence obtained and the 1821bp full length genomic sequence of GoCV-yk01 was compiled using Seqman program of DNAStar. Sequence analysis showed that the GoCV-yk01 possessed common features of circovirus included potential replication associated stem-loop structure and the Rep protein motifs. Homology analysis showed that the sequence of GoCV-yk01 had 91% approximately 93% similarity to that of Taiwan and Germany strains. Phylogenetic analysis with ClustalW, however, showed that the GoCV-yk01 was on a different branch away from Taiwan and Germany strains. Circovirus usually causes immuno-depression and results in secondary infection, as it infects rapid growing cells as lymphocyte. It is speculated that the infection of GoCV may be a part of the reason of the avian influenza outbreak of the Yongkang case. The GoCV-yk01 is the first GoCV strain reported in mainland of China.

To investigate the effect of bone marrow stem cell transplantation (BMT) on the diaphragm muscles of mdx mice, a mouse model of Duchenne muscular dystrophy (DMD).