OBJECTIVE: To modify the surface of poly(D,L-lactide) film by anhydrous ammonia gaseous plasma treatment. METHODS: The changes of contact angles were measured and surface energy were calculated. Mouse 3T3 fibroblast cells were cultured on plasma modified and control poly(D,L-lactide) films. RESULTS: It was found that the hydrophilicity and surface energy of the materials have been increased after plasma treatment. Cell culture results showed that ammonia plasma treatment could promote the cell attachment and cells growth. After 4 days culture, the cells on the plasma treated films were 2-folds quantitatively compared with that of the control films. CONCLUSION: Ammonia plasma treatment can improve the cell affinity to poly(D,L-lactide).
OBJECTIVE This paper aims to investigate the suitable cell density and the best formation time of tissue engineered autologous cartilage and to provide theoretical basis and parameters for clinical application. METHODS The chondrocytes isolated from mini swines’ ears were mixed with injectable biocompatible matrix (Pluronic), and the density of cell suspensions were 10, 20, 30, 40, 50, 60, 70 x 10(4)/ml. The chondrocyte-polymer constructs were subcutaneously injected into the abdomen of autologous swine. The specimens were observed grossly and histologically after 6 weeks, and investigated the suitable cell density. Then the chondrocyte-polymer constructs with suitable cell density were transplanted into the abdomen of autologous swine and evaluated grossly and histologically in 1, 3, 6, 9, 15 weeks after transplantation to investigate the best formation time of tissue engineered cartilage. RESULTS The experiments demonstrated that the tissue engineered autologous cartilage was similar to the natural cartilage on animals with normal immune system in histological characteristics. The optimal chondrocyte density is 50 x 10(6)/ml, and the proper harvest time is the sixth week. CONCLUSION With tissue engineering skills, we have identified the optimal chondrocyte density and the proper harvest time.
OBJECTIVE: To observe the effects of silks on attachment, shape and function of chondrocytes cultured in vitro. METHODS: The silks from silk worm cocoons were digested by trypsin and coated with polylactic acid to from three dimensional scaffolds for rabbit rib chondrocyte culture. The growth and shape of chondrocytes were observed with phase contrast microscopy, scanning electron microscopy. RESULTS: The chondrocytes were adhered to silks slowly after chondrocytes were seeded into silk scaffolds and cells fixed on silks well 1 or 2 days later. Cells began to proliferate after 3 days and multiplicative growth was observed on the 6th day. Microholes of silk scaffolds were filled with chondrocytes 2 weeks later. Scanning electron microscopy showed that there was a lot of extracellular matrix surrounding cells. CONCLUSION: Silks are ideal for attachment, growth and function maintenance of chondrocytes, and silks can be used as scaffolds for chondrocytes in three dimensional culture.
OBJECTIVE: To analysis the proliferation properties and telomerase activity of human embryonic tendon cells transformed by ptsA58H plasmid cultured in vitro continuously. METHODS: The 40th, 70th, and 75th passages of transformed human embryonic tendon cells (THETC) were adopted. The collagen secretion of THETC was detected by immunohistochemical methods, the growth curve of different passages of THETC was compared, and chromosome karyotype was analyzed. Total RNA of THETC were extracted to detect human telomerase reverse transcriptase (hTERT) mRNA expression by RT-PCR technique. RESULTS: When THETC were subcultured to 70 passages, the morphological characteristics of cells changed and began replicative senescence. THETC still could secret type I collagen normally. The chromosome of THETC was heteroploid (2n = 94). There were no hTERT mRNA expression. CONCLUSION: SV40 transfection can not make human embryonic tendon cells immortalization, on the other hand, human embryonic tendon cells transformed by ptsA58H plasmid has no tendency of malignant transformation.
Objective To investigate the feasibility of fetal liver cells for liver tissue engineering, the supporting function of poly L lactic acid (PLLA) scaffold for fetal liver cells and the effects of oncostatin M (OSM), nicotinamide (NA) and dimethyl sulfoxide(DMSO) on growth and hepatic differentiation. Methods After three dimensional PLLA scaffolds having a porous structure were prepared by using NH 4HCO 3 particle, fetal liver cells obtained from E14.5 C57BL/6CrSlc murine embryos were inoculated in the scaffolds. Cells were cultured in Williams’E medium with or without OSM, NA and DMSO for 30 days. Changes in cell number, liver-specific function, and cellular morphology were observed. Results When compared with in monolayer culture, cell number and albumin secretion increased obviously in three-dimensional PLLA. Alburmin secretion increased slightly in OSM group of monolayer culture, but increased obviously in OSM groupo of PLLA culture and in OSM/NA/DMSO group of both monlayer and PLLA cultures. Conclusion The three-dimensional PLLA scaffold is a good supporting material for the cultivation of tetal liver cells. OSM, NA and DMSO remarkaly stimulated maturation of hepatic parenchymal cells in vitro in terms of morphology and liver-specific function.
Objective To compare the biological and biomechanical characteristics of decellularized bovine jugular venous tissue-engineered valved conduit scaffolds with that of fresh bovine jugular veins. Methods Fortyeight fresh bovine jugular veins were divided into control group and experimental group with random number table method, 24 veins in each group. There were fresh bovine jugular veins in control group, decellularized bovine jugular veins in experimental group. The veins of experimental group were treated with sodium deoxyeholate plus Triton-X-100 to decellularize the cells in valves and vessel walls. The thickness, water absorption rate, water maintenance rate, destroying strength, stretch rate of valves and vessel walls in two groups were detected. Results The endothelial cell and fibroblast of valves and vessel walls in experimental group were completely decellularized, no cell fragments were retained within the matrix scaffold; collagen fiber and elastin fiber had been preserved with intact structure and wavily arrayed; deoxyribonucleic acid content of valves and vessel walls in experimental group were decreased by 97.58%, 97.25% compared with that of control group. The thickness, water absorption rate and water maintenance rate of valves and vessel walls in experimental group were lightly increased than those of control group, but there were no significant differences between them （P 〉 0. 05）. There were no significant differences in destroying strength and stretch rate of valves and vessel walls between two groups （P〉0. 05）. Conclusion Decellularized bovine jugular vein scaffold has stable biological and biomechanical characteristics and it may be ideal natural fibrous matrix for developing the tissue-engineered valved conduit by host recellularization.
Objective To study the integration of rat marrow stromal stem cells (MSCs) after transplantation into acellular extracellular matrix (AECM). Methods We got 16 femurs from 8 Kunming rats, the femurs were treated by Triton X100 toget AECM, MSCs were collected from femoral marrow of 20 Kunming rats about a mouth old by PBS 4ml, centrifugalized and primary cultured in bottles,then therat MSCs were transplanted into AECM at a concentration of 5×106/ml and culturedfor 7 days. The integration of the donor cells was observed using one phase contrast microscope, a light microscope and a scanning electron microscope (SEM).Results In AECM bone lacunas there were MSCs nucleuses stained blue. The nucleuses were unevenly distributed in AECM with more in the peripheral AECM than in the central AECM and with more in the layer anear culture medium than in the layer far away from culture medium.AECM possessed a good spatial scaffold structure, the marrow stromal stem cells were well integrated into AECM.Conclusion AECM can be usedas a good scaffold material for tissue engineered bone construction.
Objective To review the recent researches of basic fibroblast growth factor (bFGF) in tendon tissue engineering. Methods Recentoriginal related literature was extensively reviewed and analyzed. Results bFGF played an important role in establishing standard tendon tissue engineering cell lines, inducing the compound and analysis of extracellular matrix, enhancing interactions between cells and extracellular matrix and accelerating tissue engineering materials’ neovascularization. Conclusion The progresses in increasing endogenetic bFGF expression, controlling the release of exogenous bFGF and improving the bioutilization of bFGF has laid foundation for wider use of bFGF in tendon tissue engineering.
ObjectiveTo summarize the research progress of tissue-engineered bile duct in recent years. MethodsThe related literatures about the tissue-engineered bile duct were reviewed. ResultsIn recent years, the research of tissue-engineered bile duct has made a breakthrough in scaffold materials, seed cells, growth factors etc. However, the tissue-engineered bile duct is still in the research stage of animal experiments, which can not be directly applied to clinical practice. ConclusionsThe research of tissue-engineered bile duct becomes popular at present. With the rapid development of materials science and cell biology, the basic research and clinical application of tissue-engineered duct will be more in-depth research and extension, which might bring new ideas and therapeutic measures for patients with biliary defect or stenosis.
Objective To investigate the possibility of constructing eukaryoticexpression vector for human angiopoietin 1（hAng-1），transfecting it to bonemarrow mesenchymal stem cells (MSCs) so as to repair bone defect. Methods The eukaryotic expression vector pcDNA3-hAng-1 was constructed by recombinant DNA technique, transfected into MSCs by liposome DOTAP, and selected with G418. The hAng-1 expression of mRNA and protein was detected by reverse transcript-PCR and Western Blot. Results After the recombinant eukaryotic expressionvector for hAng-1 was digested with Xho-I and BamH-I, electrophoresis revealed 1.4 kb fragment for hAng-1 gene and 5.4 kb fragment for pcDNA3 vector. In the transfected MSCs, the mRNA and protein expression of hAng-1 gene were detected with reverse transcriptPCR and Western Blot. Conclusion The constructed eukaryotic expression vector hAng-1 could be expressed in the transfected MSCs, thus to provide the basis for bone repair with tissue engineering.