Ex vivo expansion and pluripotential differentiation of cryopreserved human bone marrow mesenchymal stem cells

This study is aimed at investigating the potentials of ex vivo expansion and pluri-differentiation of cryopreservation of adult human bone marrow mesenchymal stem cells （hMSCs） into chondrocytes, adipocytes and neurocytes. Cryopreserved hMSCs were resuscitated and cultured for 15 passages, and then induced into chondrocytes, adipocytes and neurocytes with corresponding induction medium. The induced cells were observed for morphological properties and detected for expressions of type II collagen, triglyceride or neuron-specific enolase and nestin. The result showed that the resuscitated cells could differentiate into chondrocytes after exposure to transforming growth factor 61 （TGF-~0, insulin-like growth factor I （IGF-I） and vitamin C （Vc）, and uniformly changed morphologically from a spindle-like fibroblastic appearance to a polygonal shape in three weeks. The induced cells were heterochromatic to safranin O and expressed cartilage matrix-procollagenal （If） mRNA. The resuscitated cells cultured in induction medium consisting of dexamethasone, 3-isobutyl-l-methylxanthine, indomethacin and IGF-I showed adipogenesis, and lipid vacuoles accumulation was detectable after 21 d. The resuscitated hMSCs were also induced into neurocytes and expressed nestin and neuron specific endolase （NSE） that were special surface markers associated with neural cells at different stage. This study suggested that the resuscitated hMSCs should be still a population ofpluripotential cells and that it could be used for establishing an abundant bMSC reservoir for further experiment and treatment of various clinical discases.     

Preliminary study on the freeze-drying of human bone marrow-derived mesenchymal stem cells

Long-term preservation and easy transportation of human bone marrow-derived mesenchymal stem cells (hBM-MSCs) will facilitate their application in medical treatment and bioengineering. A pilot study on the freeze-drying of hBM-MSCs was carried out. hBM-MSCs were loaded with trehalose. The glass transition temperature of the freeze-drying suspension was measured to provide information for the cooling and primary drying experiment. After freeze-drying, various rehydration processes were tested. The highest recovery rate of hBM-MSCs was (69.33±13.08)%. Possible methods to improve freeze-drying outcomes are discussed. In conclusion, the present study has laid a foundation for the freeze-drying hBM-MSCs.     

Macrophage migration inhibitory factor protects bone marrow mesenchymal stem cells from hypoxia/ischemia-induced apoptosis by regulating lncRNA MEG3

Journal of Zhejiang University-SCIENCE B - This research was performed to explore the effect of macrophage migration inhibitory factor (MIF) on the apoptosis of bone marrow mesenchymal stem cells...     

Rapid Communication:Preliminary study on the freeze-drying of human bone marrow-derived mesenchymal stem cells

Long-term preservation and easy transportation of human bone marrow-derived mesenchymal stem cells(hBM-MSCs) will facilitate their application in medical treatment and bioengineering.A pilot study on the freeze-drying of hBM-MSCs was carried out.hBM-MSCs were loaded with trehalose.The glass transition temperature of the freeze-drying suspension was measured to provide information for the cooling and primary drying experiment.After freeze-drying,various rehydration processes were tested.The highest recovery rate of hBM-MSCs was(69.33± 13.08) %.Possible methods to improve freeze-drying outcomes are discussed.In conclusion,the present study has laid a foundation for the freeze-drying hBM-MSCs.     

Protective paracrine effect of mesenchymal stem cells on cardiomyocytes

Objective  The aim of this study was to test the protective effect of mesenchymal stem cells (MSCs) on cardiomyocytes in vitro and to investigate the anti-apoptotic signaling pathway. Methods  MSCs from Sprague-Dawley (SD) rats were separated and cultured. MSC medium was collected from MSCs cultured in serum-free Dulbecco’s modified eagle medium (DMEM) under hypoxia. Cultured cardiomyocytes from neonatal SD rats were exposed to hypoxia/reoxygenation (H/R) and treated with MSC medium. The apoptotic cardiomyocytes were stained with Annexin-V-fluorescein isothiocyanate (FITC), Hoechst 33342 and terminal deoxynucleotidyl transferase-mediated dUTP nick-end labeling (TUNEL). The mitochondrial transmembrane potential of cardiomyocytes was assessed using a fluorescence microscope. The expression of Bcl-2, Bax, cytochrome C, apoptosis-induced factor (AIF), and caspase-3 was tested by Western blot analysis. Results  Our data demonstrated that MSC medium reduced H/R-induced cardiomyocyte apoptosis, increased the Bcl-2/Bax ratio, and reduced the release of cytochrome C and AIF from mitochondria into the cytosol. Conclusion  MSCs protected the cardiomyocytes from H/R-induced apoptosis through a mitochondrial pathway in a paracrine manner. Project supported by the National Natural Science Foundation of China (No. 30670868) and the Natural Science Foundation of Zhejiang Province, China (No. R206007)     

Human bone marrow-derived mesenchymal stem cells transplanted into damaged rabbit heart to improve heart function

INTRODUCTION Congestive heart failure is the end stage of manycardiovascular diseases. Myocardial infarction (MI)is a life-threatening event that may cause suddencardiac death and heart failure. Despite considerableadvances in diagnosis and treatment of heart disease,cardiac dysfunction after MI is still the majorworldwide cardiovascular disorder. Damaged myo-cardium after acute MI is gradually replaced by fi-brotic noncontractile cells to form scar tissue. Thedeveloping ventricul…     

骨髓细胞的模糊识别

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Tissue-engineered composite scaffold of poly(lactide-<Emphasis Type="Italic">co</Emphasis>-glycolide) and hydroxyapatite nanoparticles seeded with autologous mesenchymal stem cells for bone regeneration

Objective

A new therapeutic strategy using nanocomposite scaffolds of grafted hydroxyapatite (g-HA)/poly(lactide-co-glycolide) (PLGA) carried with autologous mesenchymal stem cells (MSCs) and bone morphogenetic protein-2 (BMP-2) was assessed for the therapy of critical bone defects. At the same time, tissue response and in vivo mineralization of tissue-engineered implants were investigated.

Methods

A composite scaffold of PLGA and g-HA was fabricated by the solvent casting and particulate-leaching method. The tissue-engineered implants were prepared by seeding the scaffolds with autologous bone marrow MSCs in vitro. Then, mineralization and osteogenesis were observed by intramuscular implantation, as well as the repair of the critical radius defects in rabbits.

Results

After eight weeks post-surgery, scanning electron microscopy (SEM) and energy dispersive X-ray spectroscopy (EDX) revealed that g-HA/PLGA had a better interface of tissue response and higher mineralization than PLGA. Apatite particles were formed and varied both in macropores and micropores of g-HA/PLGA. Computer radiographs and histological analysis revealed that there were more and more quickly formed new bone formations and better fusion in the bone defect areas of g-HA/PLGA at 2–8 weeks post-surgery. Typical bone synostosis between the implant and bone tissue was found in g-HA/PLGA, while only fibrous tissues formed in PLGA.

Conclusions

The incorporation of g-HA mainly improved mineralization and bone formation compared with PLGA. The application of MSCs can enhance bone formation and mineralization in PLGA scaffolds compared with cell-free scaffolds. Furthermore, it can accelerate the absorption of scaffolds compared with composite scaffolds.

     

Allograftic bone marrow-derived mesenchymal stem cells transplanted into heart infarcted model of rabbit to renovate infarcted heart

Objective: To investigate the directed transplantation of allograftic bone marrow-derived mesenchymal stem cells (MSCs) in myocardial infarcted (MI) model rabbits. Materials and Methods: Rabbits were divided into 3 groups, heart infarcted model with MSCs transplanted treatment (MSCs group, n=12), heart infarcted model with PBS injection (control group, n=20), sham operation with PBS injection (sham group, n=l 7). MSCs labelled by BrdUrd were injected into the MI area of the MSCs group. The same volume of PBS was injected into the MI area of the control group and sham group. The mortality, LVIDd, LVIDs and LVEF Of the two groups were compared 4 weeks later. Tropomyosin inhibitory component (Tn I) and BrdUrd immunohistochemistry identified the engrafted cells 4 weeks after transplantation. Result: The mortality of the MSCs group was 16.7% (2/12), and remarkably lower than the control group's mortality [35% (7/20) (P＜0.05)].Among the animals that survived for 4 weeks, the LVIDd and LVIDs of the MSCs group after operation were 1.17±0.21 cm and 0.74±0.13 cm, and remarkably lower than those of the model group, which were 1.64±0.14 cm and 1.19±0.12 cm (P＜0.05); the LVEF of the MSCs group after operation was 63±6%, and remarkably higher than that of the model group,which was 53±6% (P＜0.05). Among the 10 cases of animals that survived for 4 weeks in the MSCs group, in 8 cases (80%),the transplanted cells survived in the non MI, MI region and its periphery, and even farther away; part of them differentiated into cardiomyocytes; in 7 cases (70%), the transplanted cells participated in the formation of blood vessel tissue in the MI region. Conclusion: Transplanted allograftic MSCs can survive and differentiate into cardiomyocytes, form the blood vessels in the MI region. MSCs transplantation could improve the heart function after MI.     

Allograftic bone marrow-derived mesenchymal stem cells transplanted into heart infarcted model of rabbit to renovate infarcted heart

Objective: To investigate the directed transplantation of allograftic bone marrow-derived mesenchymal stem cells (MSCs) in myocardial infarcted (MI) model rabbits. Materials and Methods: Rabbits were divided into 3 groups, heart infarcted model with MSCs transplanted treatment (MSCs group, n=12), heart infarcted model with PBS injection (control group, n=20), sham operation with PBS injection (sham group, n=17). MSCs labelled by BrdUrd were injected into the MI area of the MSCs group. The same volume of PBS was injected into the MI area of the control group and sham group. The mortality, LVIDd, LVIDs and LVEF of the two groups were compared 4 weeks later. Tropomyosin inhibitory component (Tn I) and BrdUrd immunohistochemistry identified the engrafted cells 4 weeks after transplantation. Result: The mortality of the MSCs group was 16.7% (2/12), and remarkably lower than the control group's mortality [35% (7/20) (P<0.05)]. Among the animals that survived for 4 weeks, the LVIDd and LVIDs of the MSCs group     

Immunomodulative effects of mesenchymal stem cells derived from human embryonic stem cells in vivo and in vitro

Objective  

Human embryonic stem cells (hESCs) have recently been reported as an unlimited source of mesenchymal stem cells (MSCs). The present study not only provides an identical and clinically compliant MSC source derived from hESCs (hESC-MSCs), but also describes the immunomodulative effects of hESC-MSCs in vitro and in vivo for a carbon tetrachloride (CCl₄)-induced liver inflammation model.     

Effects of insulin-like growth factor-1 on the properties of mesenchymal stem cells in vitro

Objective  

To explore the effects of insulin-like growth factor-1 (IGF-1) on migration, proliferation and differentiation of mesenchymal stem cells (MSCs).     

钛表面仿生矿化磷酸钙涂层的工艺研究

以工业纯钛为基体,采用仿生法制备钛基磷酸盐涂层复合材料。对钛基进行酸碱活化处理和热处理后浸入模拟体液进行矿化,分析碱液浓度和处理时间、热处理温度等因素对钛基表面活性的影响。研究发现,当碱溶液浓度为9 mol/L、处理时间为10 h时,钛基体的表面粗糙度和表面能达到最大;随着热处理温度升高,钛基在模拟体液中矿化形成的磷灰石增多。但当热处理温度超过700 ℃时,钛基体表面的二氧化钛凝胶层结构改变,钛表面层与溶液的离子交换能力下降,磷灰石形成量减少。该研究可为钛及其合金在骨植入材料中的临床应用提供理论和实践依     

Effects of zinc-substituted nano-hydroxyapatite coatings on bone integration with implant surfaces

Objective:The purpose of this study was to investigate the effects of a zinc-substituted nano-hydroxyapatite(Zn-HA) coating,applied by an electrochemical process,on implant osseointegraton in a rabbit model.Methods:A Zn-HA coating or an HA coating was deposited using an electrochemical process.Surface morphology was examined using field-emission scanning electron microscopy.The crystal structure and chemical composition of the coatings were examined using an X-ray diffractometer(XRD) and Fourier transform infrared spectroscopy(FTIR).A total of 78 implants were inserted into femurs and tibias of rabbits.After two,four,and eight weeks,femurs and tibias were retrieved and prepared for histomorphometric evaluation and removal torque(RTQ) tests.Results:Rod-like HA crystals appeared on both implant surfaces.The dimensions of the Zn-HA crystals seemed to be smaller than those of HA.XRD patterns showed that the peaks of both coatings matched well with standard HA patterns.FTIR spectra showed that both coatings consisted of HA crystals.The Zn-HA coating significantly improved the bone area within all threads after four and eight weeks(P<0.05),the bone to implant contact(BIC) at four weeks(P<0.05),and RTQ values after four and eight weeks(P<0.05).Conclusions:The study showed that an electrochemically deposited Zn-HA coating has potential for improving bone integration with an implant surface.     

Osteogenic differentiation of mesenchymal stem cells promoted by overexpression of connective tissue growth factor

Objective: Large segmental bone defect repair remains a clinical and scientific challenge with increasing interest focusing on combining gene transfection with tissue engineering techniques. The aim of this study is to investigate the effect of connective tissue growth factor (CTGF) on the proliferation and osteogenic differentiation of the bone marrow mesenchymal stem cells (MSCs). Methods: A CTGF-expressing plasmid (pCTGF) was constructed and transfected into MSCs. Then expressions of bone morphogenesis-related genes, proliferation rate, alkaline phosphatase activity, and mineralization were examined to evaluate the osteogenic potential of the CTGF gene-modified MSCs. Results: Overexpression of CTGF was confirmed in pCTGF-MSCs. pCTGF transfection significantly enhanced the proliferation rates of pCTGF-MSCs (P<0.05). CTGF induced a 7.5-fold increase in cell migration over control (P<0.05). pCTGF transfection enhanced the expression of bone matrix proteins, such as bone sialo-protein, osteocalcin, and collagen type I in MSCs. The levels of alkaline phosphatase (ALP) activities of pCTGF-MSCs at the 1st and 2nd weeks were 4.0- and 3.0-fold higher than those of MSCs cultured in OS-medium, significantly higher than those of mock-MSCs and normal control MSCs (P<0.05). Overexpression of CTGF in MSCs enhanced the capability to form mineralized nodules. Conclusion: Overexpression of CTGF could improve the osteogenic differentiation ability of MSCs, and the CTGF gene-modified MSCs are potential as novel cell resources of bone tissue engineering.     

载Ag多孔TiO_2薄膜的制备及其光致变色性能

为了制备具有良好光致变色性能的载Ag的TiO2薄膜,利用PEG2000和PEG4000在载Ag的TiO2薄膜中制造出直径在几十纳米以上的密集孔洞,使薄膜呈现出显著的光致变色现象;比较了PEG用量、分子量和镀银时间对薄膜光致变色性能的影响。结果表明:无论PEG用量增加或分子量增加都会导致薄膜中孔的直径增大,直径50~100nm的密集孔洞最有利于提高光致变色速率;孔洞对Ag颗粒的尺寸、形状有一定限制作用,但随着孔径的增加,限制作用减弱;Ag颗粒的尺寸、形状、分布密度更加依赖于镀银时间,决定差分吸收光谱上烧孔的形状和位置,过长的镀银时间导致额外的烧孔和烧孔宽化。     

Effects of nanofibers on mesenchymal stem cells: environmental factors affecting cell adhesion and osteogenic differentiation and their mechanisms

Journal of Zhejiang University-SCIENCE B - Nanofibers can mimic natural tissue structure by creating a more suitable environment for cells to grow, prompting a wide application of nanofiber...