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Marrow Mesenchymal Stem Cells (marrow + mesenchymal_stem_cell)
Kinds of Marrow Mesenchymal Stem Cells Selected AbstractsEngineering of Vascular Grafts With Genetically Modified Bone Marrow Mesenchymal Stem Cells on Poly (Propylene Carbonate) GraftARTIFICIAL ORGANS, Issue 12 2006Jun Zhang Abstract:, Bone marrow mesenchymal stem cells (MSCs) have demonstrated their pluripotency to differentiate into different cell lineages and may be an alternative cell source for vascular tissue engineering. The objective of this study is to create small diameter vessels by seeding and culture of genetically modified MSCs onto a synthetic polymer scaffold produced by an electrospinning technique. A tubular scaffold (2 mm in diameter) with a microstructure of nonwoven fibers was produced by electrospinning of poly (propylene carbonate) (PPC). Rat MSCs obtained from bone marrow were expanded in culture and modified with vasculoprotective gene endothelial nitric oxide synthase (eNOS) or marker gene green fluorescent protein (GFP). These MSCs were seeded onto the electrospun fibrous grafts (internal diameter = 2 mm), and cultured in 5% CO2 at 37°C. The growth of MSCs in the scaffold was analyzed with scanning electron microscopy (SEM) and hematoxylin and eosin (H&E) staining. The gene transfer and transgenic gene expression were examined with fluorescence-activated cell sorting (FACS), immunochemical staining, reverse transcriptase-polymerase chain reaction (RT-PCR), and western blot. The production of nitric oxide (NO) by the engineered vessels was measured with an NO detection kit. Our data showed that the seeded cells integrated with the microfibers of the scaffold to form a three-dimensional cellular network, indicating a favorable interaction between this synthetic PPC scaffold with MSCs. High transduction efficiency was obtained with the use of concentrated retrovirus in the gene transfection of MSCs. The eNOS gene transcripts and protein were detected in the grafts seeded with eNOS-modified MSCs by RT-PCR and immunochemical staining. The amount of NO produced by grafts seeded with eNOS-modified MSCs was comparable to that produced by native blood vessels, and it was significantly higher than that in the grafts seeded with nonmodified MSCs. In summary, the vascular graft produced by culture of eNOS gene-modified MSCs onto the electrospun tubular scaffolds shows promising results in terms of function. The use of MSCs and therapeutic genes in tissue engineering of blood vessels could be helpful in improving vessel regeneration and patency. [source] Tissue regeneration of the vocal fold using bone marrow mesenchymal stem cells and synthetic extracellular matrix injections in rats,THE LARYNGOSCOPE, Issue 3 2010Beatriz Quinchia Johnson DDS Abstract Objectives/Hypothesis. To determine the effectiveness of bone marrow mesenchymal stem cell (BM-MSC) transplantation in isolation or within a synthetic extracellular matrix (sECM) for tissue regeneration of the scarred vocal fold lamina propria. Methods. In vitro stability and compatibility of mouse BM-MSC embedded in sECM was assessed by flow cytometry detection of BM-MSC marker expression and proliferation. Eighteen rats were subjected to vocal fold injury bilaterally, followed by 1 month post-treatment with unilateral injections of saline or sECM hydrogel (Extracel; Glycosan BioSystems, Inc., Salt Lake City, UT), green fluorescence protein (GFP)-mouse BM-MSC, or BM-MSC suspended in sECM. Outcomes measured 1 month after treatment included procollagen-III, fibronectin, hyaluronan synthase-III (HAS3), hyaluronidase (HYAL3), smooth muscle actin (SMA), and transforming growth factor-beta 1(TGF-,1) mRNA expression. The persistence of GFP BM-MSC, proliferation, apoptosis, and myofibroblast differentiation was assessed by immunofluorescence. Results. BM-MSC grown in vitro within sECM express Sca-1, are positive for hyaluronan receptor CD44, and continue to proliferate. In the in vivo study, groups injected with BM-MSC had detectable GFP-labeled BM-MSC remaining and showed proliferation and low apoptotic or myofibroblast markers compared to the contralateral side. Embedded BM-MSC in the sECM group exhibited increased levels of procollagen III, fibronectin, and TGF-,1. BM-MSC within sECM downregulated the expression of SMA compared to BM-MSC alone and exhibited upregulation of HYAL3 and no change in HAS3 compared to saline. Conclusions. Treatment of vocal fold scarring with BM-MSC injected in a sECM displayed the most favorable outcomes in ECM production, hyaluronan metabolism, myofibroblast differentiation, and production of TGF-,1. Furthermore, the combined treatment had no detectable cytotoxicity and preserved local cell proliferation. Laryngoscope, 2010 [source] Novel Strategy to Engineer Trachea Cartilage Graft With Marrow Mesenchymal Stem Cell Macroaggregate and Hydrolyzable ScaffoldARTIFICIAL ORGANS, Issue 5 2010Liangqi Liu Abstract Limited donor sites of cartilage and dedifferentiation of chondrocytes during expansion, low tissue reconstruction efficiency, and uncontrollable immune reactions to foreign materials are the main obstacles to overcome before cartilage tissue engineering can be widely used in the clinic. In the current study, we developed a novel strategy to fabricate tissue-engineered trachea cartilage grafts using marrow mesenchymal stem cell (MSC) macroaggregates and hydrolyzable scaffold of polylactic acid,polyglycolic acid copolymer (PLGA). Rabbit MSCs were continuously cultured to prepare macroaggregates in sheet form. The macroaggregates were studied for their potential for chondrogenesis. The macroaggregates were wrapped against the PLGA scaffold to make a tubular composite. The composites were incubated in spinner flasks for 4 weeks to fabricate trachea cartilage grafts. Histological observation and polymerase chain reaction array showed that MSC macroaggregates could obtain the optimal chondrogenic capacity under the induction of transforming growth factor-,. Engineered trachea cartilage consisted of evenly spaced lacunae embedded in a matrix rich in proteoglycans. PLGA scaffold degraded totally during in vitro incubation and the engineered cartilage graft was composed of autologous tissue. Based on this novel, MSC macroaggregate and hydrolyzable scaffold composite strategy, ready-to-implant autologous trachea cartilage grafts could be successfully fabricated. The strategy also had the advantages of high efficiency in cell seeding and tissue regeneration, and could possibly be used in future in vivo experiments. [source] Cord blood mesenchymal stem cells propel human dendritic cells to an intermediate maturation state and boost interleukin-12 production by mature dendritic cellsIMMUNOLOGY, Issue 4 2009Lieke C. J. Van Den Berk Summary Pathogen-derived entities force the tissue-resident dendritic cells (DCs) towards a mature state, followed by migration to the draining lymph node to present antigens to T cells. Bone marrow mesenchymal stem cells (MSCs) modulate the differentiation, maturation and function of DCs. In umbilical cord blood an immature MSC population was identified. Remarkably, these immature stem cells modulated DCs in a different way. Marker expression was unchanged during the differentiation of monocytes towards immature DCs (iDCs) when cocultured with cord blood MSC [unrestricted somatic stem cells (USSCs)]. The maturation to mature DCs (mDCs) was enhanced when DCs were co-cultured with USSC, as evidenced by the up-regulation of costimulatory molecules. Endocytosis of dextran by iDCs was hampered in the presence of USSCs, which is indicative for the maturation of iDCs. Despite this maturation, the migration of iDCs cocultured with USSCs appeared to be identical to iDCs cultured alone. However, USSCs increased the migration of mDCs towards CCL21 and boosted interleukin-12 production. So, USSCs mature iDCs, thereby redirecting the antigen-uptake phenotype towards a mature phenotype. Furthermore, DC maturation by lipopolysaccharide (LPS) or USSCs reflects two distinct pathways because migration was unaffected when iDCs were matured by coculture with USSCs, while it was strongly enhanced in the presence of LPS. DCs are able to discriminate the different MSC subtypes, resulting in diverse differentiation programmes. [source] An innovative method to obtain porous PLLA scaffolds with highly spherical and interconnected poresJOURNAL OF BIOMEDICAL MATERIALS RESEARCH, Issue 1 2008Cédryck Vaquette Abstract Scaffolding is an essential issue in tissue engineering and scaffolds should answer certain essential criteria: biocompatibility, high porosity, and important pore interconnectivity to facilitate cell migration and fluid diffusion. In this work, a modified solvent casting-particulate leaching out method is presented to produce scaffolds with spherical and interconnected pores. Sugar particles (200,300 ,m and 300,500 ,m) were poured through a horizontal Meker burner flame and collected below the flame. While crossing the high temperature zone, the particles melted and adopted a spherical shape. Spherical particles were compressed in plastic mold. Then, poly- L -lactic acid solution was cast in the sugar assembly. After solvent evaporation, the sugar was removed by immersing the structure into distilled water for 3 days. The obtained scaffolds presented highly spherical interconnected pores, with interconnection pathways from 10 to 100 ,m. Pore interconnection was obtained without any additional step. Compression tests were carried out to evaluate the scaffold mechanical performances. Moreover, rabbit bone marrow mesenchymal stem cells were found to adhere and to proliferate in vitro in the scaffold over 21 days. This technique produced scaffold with highly spherical and interconnected pores without the use of additional organic solvents to leach out the porogen. © 2007 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 2008 [source] Chemical characteristics and cytocompatibility of collagen-based scaffold reinforced by chitin fibers for bone tissue engineeringJOURNAL OF BIOMEDICAL MATERIALS RESEARCH, Issue 2 2006Xiaoming Li Abstract Chitin is a kind of seemly material to match PLLA for a scaffold, which may create an appropriate environment for the regeneration of tissues. In this study, we prepared and evaluated a new nano-hydroxyapatite/collagen/PLLA (nHACP) scaffold reinforced by chitin fibers for bone-tissue engineering. The chitin fibers were crosslinked with PLLA by dicyclohexylcarbodimide (DCC). The chemical characteristics were evaluated by Fourier transformed infrared (FTIR) spectroscopy and X-ray photoelectron spectroscopy (XPS). The mechanical strength was measured by compressive tests. The fibers, crosslinked with PLLA, could enhance the compressive strength of the scaffold about four times. Human marrow mesenchymal stem cells (MSCs) culture showed that the reinforced nHACP scaffolds were more cytocompatible than that without reinforcement. The crosslinks hardly affected the cytocompatibility of the reinforced scaffolds. The results suggested that the reinforced scaffolds (DCC crosslinked) might be a promising candidate for bone-tissue engineering. © 2005 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 2006 [source] Aging and lung injury repair: A role for bone marrow derived mesenchymal stem cellsJOURNAL OF CELLULAR BIOCHEMISTRY, Issue 3 2008Ana L. Mora Abstract The incidence of lung fibrosis increases with age. Aging is associated with modifications in the intracellular and extracellular environment including alteration of the extracellular matrix, imbalance of the redox state, accumulation of senescent cells and potential alteration of the recruitment of bone marrow mesenchymal stem cells. The combination of these senescence-related alterations in the lung and in bone marrow progenitor cells might be responsible of the higher susceptibility to lung fibrosis in elderly individuals. The understanding of these age related changes must be considered in the rationale for the development of therapeutic interventions to control lung injury and fibrosis. J. Cell. Biochem. 105: 641,647, 2008. © 2008 Wiley-Liss, Inc. [source] Identification of marker genes distinguishing human periodontal ligament cells from human mesenchymal stem cells and human gingival fibroblastsJOURNAL OF PERIODONTAL RESEARCH, Issue 3 2007T. Fujita Background and Objective:, Molecular gene markers, which can distinguish human bone marrow mesenchymal stem cells from human fibroblasts, have recently been reported. Messenger RNA levels of tissue factor pathway inhibitor-2, major histocompatibility complex-DR-,, major histocompatibility complex-DR-,, and neuroserpin are higher in human bone marrow mesenchymal stem cells than in human fibroblasts. However, human bone marrow mesenchymal stem cells express less apolipoprotein D mRNA than human fibroblasts. Periodontal ligament cells are a heterogeneous cell population including fibroblasts, mesenchymal stem cells, and progenitor cells of osteoblasts or cementoblasts. The use of molecular markers that distinguish human bone marrow mesenchymal stem cells from human fibroblasts may provide insight into the characteristics of human periodontal ligament cells. In this study, we compared the molecular markers of human periodontal ligament cells with those of human bone marrow mesenchymal stem cells and human gingival fibroblasts. Material and Methods:, The mRNA expression of the molecular gene markers was analyzed using real-time polymerase chain reaction. Statistical differences were determined with the two-sided Mann,Whitney U -test. Results:, Messenger RNA levels of major histocompatibility complex-DR-, and major histocompatibility complex-DR-, were lower and higher, respectively, in human periodontal ligament cells than in human bone marrow mesenchymal stem cells or human gingival fibroblasts. Human periodontal ligament cells showed the lowest apolipoprotein D mRNA levels among the three types of cells. Conclusion:, Human periodontal ligament cells may be distinguished from human bone marrow mesenchymal stem cells and human gingival fibroblasts by the genes for apolipoprotein D, major histocompatibility complex-DR-,, and major histocompatibility complex-DR-,. [source] Adipogenic Effect of Alcohol on Human Bone Marrow-Derived Mesenchymal Stem CellsALCOHOLISM, Issue 7 2004Frederick H. Wezeman Background: In addition to a decrease in bone mass in alcoholics their osteopenic skeletons show an increase in bone marrow adiposity. Human bone marrow mesenchymal stem cells (hMSC) in vivo differentiate into several phenotypes including osteogenic and adipogenic cells, both of which remain as resident populations of bone marrow. In vitro, the lineage commitment and differentiation of hMSC toward the adipogenic pathway can be promoted by alcohol. Methods: Human male and female mesenchymal stem cells from joint replacement surgery were cultured. Cells were grouped as: 1) Control (no additions to the culture medium), 2) EtOH (50 mm alcohol added to the culture medium), 3) OS (osteogenic inducers added to the culture medium), and 4) OS + EtOH (osteogenic inducers and 50 mm alcohol added to the culture medium). Cultures stained with Nile Red confirmed the development of differentiated adipocytes. Population analysis was performed using fluorescence-activated cell sorting. Gene expression of early, middle, late, and terminal differentiation stage markers (PPAR),2, lipoprotein lipase, adipsin, leptin, and adipocyte P2 (aP2)] was studied by Northern hybridization, and protein synthesis of aP2 was determined by Western analysis. Results: Nile red staining confirmed increased adipocyte development 10 days after the onset of treatment with 50 mm alcohol and osteogenic induction. By day 21 the number of adipocytes increased to 13.6% of the total population. Alcohol up-regulated the gene expression of PPAR,2 whereas no up-regulation was observed for the other genes. Protein production of aP2 was significantly increased in hMSC cells by culture in the presence of alcohol. Conclusions: The data suggest that alcohol's adipogenic effect on cultured hMSC is through up-regulation of PPAR,2 at the point of lineage commitment as well as through enhancement of lipid transport and storage through increased aP2 synthesis. The alcohol-induced expression and synthesis changes account for the increased Nile red staining of cultured hMSC. [source] Transplantation of bone marrow mesenchymal stem cells reduces lesion volume and induces axonal regrowth of injured spinal cordNEUROPATHOLOGY, Issue 3 2010Weidong Gu It has been demonstrated that transplantation of bone marrow mesenchymal stem cells (BMSCs) improves recovery of injured spinal cord in animal models. However, the mechanism of how BMSCs promote repair of injured spinal cord remains under investigation. The present study investigated the neural differentiation of BMSCs, the lesion volume and axonal regrowth of injured spinal cord after transplantation. Seven days after spinal cord injury, 3 × 105 BMSCs or PBS (control) was delivered into the injury epicenter of the spinal cord. At 8 weeks after spinal cord injury, transplantation of BMSCs reduced the volume of cavity and increased spared white matter as compared to the control. BMSCs did not express the cell marker of neurons, astrocytes and oligodendrocytes in injured spinal cord. Transmission electron microscopic examination displayed an increase in the number of axons in BMSC rats. The effect of BMSCs on growth of neuronal process was further investigated by using a coculture system. The length and the number of neurites from spinal neurons significantly increased when they cocultured with BMSCs. PCR and immunochemical analysis showed that BMSCs expressed brain-derived neurotrophic factor (BDNF) and glia cell line-derived neurotrophic factor (GDNF). These findings demonstrate that transplantation of BMSCs reduces lesion volume and promotes axonal regrowth of injured spinal cord. [source] Stem cell-based cell therapy for Huntington disease: A reviewNEUROPATHOLOGY, Issue 1 2008Manho Kim Huntington disease (HD) is a devastating neurodegenerative disorder and no proven medical therapy is currently available to mitigate its clinical manifestations. Although fetal neural transplantation has been tried in both preclinical and clinical investigations, the efficacy is not satisfactory. With the recent explosive progress of stem cell biology, application of stem cell-based therapy in HD is an exciting prospect. Three kinds of stem cells, embryonic stem cells, bone marrow mesenchymal stem cells and neural stem cells, have previously been utilized in cell therapy in animal models of neurological disorders. However, neural stem cells were preferably used by investigators in experimental HD studies, since they have a clear capacity to become neurons or glial cells after intracerebral or intravenous transplantation, and they induce functional recovery. In this review, we summarize the current state of cell therapy utilizing stem cells in experimental HD animal models, and discuss the future considerations for developing new therapeutic strategies using neural stem cells. [source] Human neural stem cells genetically modified for brain repair in neurological disordersNEUROPATHOLOGY, Issue 3 2004Seung U. Kim Existence of multipotent neural stem cells (NSC) has been known in developing or adult mammalian CNS, including humans. NSC have the capacity to grow indefinitely and have multipotent potential to differentiate into three major cell types of CNS, neurons, astrocytes and oligodendrocytes. Stable clonal lines of human NSC have recently been generated from the human fetal telencephalon using a retroviral vector encoding v-myc. One of the NSC lines, HB1.F3, carries normal human karyotype of 46XX and has the ability to self-renew, differentiate into cells of neuronal and glial lineages, and integrate into the damaged CNS loci upon transplantation into the brain of animal models of Parkinson disease, HD, stroke and mucopolysaccharidosis. F3 human NSC were genetically engineered to produce L-dihydroxyphenylalanine (L-DOPA) by double transfection with cDNA for tyrosine hydroxylase and guanosine triphosphate cylohydrolase-1, and transplantation of these cells in the brain of Parkinson disease model rats led to L-DOPA production and functional recovery. Proactively transplanted F3 human NSC in rat striatum, supported the survival of host striatal neurons against neuronal injury caused by 3-nitropro-pionic acid in rat model of HD. Intravenously introduced through the tail vein, F3 human NSC were found to migrate into ischemic lesion sites, differentiate into neurons and glial cells, and improve functional deficits in rat stroke models. These results indicate that human NSC should be an ideal vehicle for cell replacement and gene transfer therapy for patients with neurological diseases. In addition to immortalized human NSC, immortalized human bone marrow mesenchymal stem cell lines have been generated from human embryonic bone marrow tissues with retroviral vectors encording v-myc or teromerase gene. These immortalized cell lines of human bone marrow mesenchymal stem cells differentiated into neurons/glial cells, bone, cartilage and adipose tissue when they were grown in selective inducing media. There is further need for investigation into the neurogenic potential of the human bone marrow stem cell lines and their utility in animal models of neurological diseases. [source] Tissue regeneration of the vocal fold using bone marrow mesenchymal stem cells and synthetic extracellular matrix injections in rats,THE LARYNGOSCOPE, Issue 3 2010Beatriz Quinchia Johnson DDS Abstract Objectives/Hypothesis. To determine the effectiveness of bone marrow mesenchymal stem cell (BM-MSC) transplantation in isolation or within a synthetic extracellular matrix (sECM) for tissue regeneration of the scarred vocal fold lamina propria. Methods. In vitro stability and compatibility of mouse BM-MSC embedded in sECM was assessed by flow cytometry detection of BM-MSC marker expression and proliferation. Eighteen rats were subjected to vocal fold injury bilaterally, followed by 1 month post-treatment with unilateral injections of saline or sECM hydrogel (Extracel; Glycosan BioSystems, Inc., Salt Lake City, UT), green fluorescence protein (GFP)-mouse BM-MSC, or BM-MSC suspended in sECM. Outcomes measured 1 month after treatment included procollagen-III, fibronectin, hyaluronan synthase-III (HAS3), hyaluronidase (HYAL3), smooth muscle actin (SMA), and transforming growth factor-beta 1(TGF-,1) mRNA expression. The persistence of GFP BM-MSC, proliferation, apoptosis, and myofibroblast differentiation was assessed by immunofluorescence. Results. BM-MSC grown in vitro within sECM express Sca-1, are positive for hyaluronan receptor CD44, and continue to proliferate. In the in vivo study, groups injected with BM-MSC had detectable GFP-labeled BM-MSC remaining and showed proliferation and low apoptotic or myofibroblast markers compared to the contralateral side. Embedded BM-MSC in the sECM group exhibited increased levels of procollagen III, fibronectin, and TGF-,1. BM-MSC within sECM downregulated the expression of SMA compared to BM-MSC alone and exhibited upregulation of HYAL3 and no change in HAS3 compared to saline. Conclusions. Treatment of vocal fold scarring with BM-MSC injected in a sECM displayed the most favorable outcomes in ECM production, hyaluronan metabolism, myofibroblast differentiation, and production of TGF-,1. Furthermore, the combined treatment had no detectable cytotoxicity and preserved local cell proliferation. Laryngoscope, 2010 [source] A Novel Possible Strategy Based on Self-Assembly Approach to Achieve Complete Periodontal RegenerationARTIFICIAL ORGANS, Issue 7 2010Zhen-Hua Yang Abstract Limitations of current regeneration modalities underscore the importance of restoring the three-dimensional (3D) microenvironment of periodontal development, which is able to elicit the intrinsic capacity of mesenchymal stem cells to proceed to engage in a redevelopment-like program. With increased attention for the potential therapeutic applications of periodontal ligament stem cells (PDLSCs) in periodontal regeneration, it has been proposed that bone marrow mesenchymal stem cells (BMMSCs) are very likely another cell source of physiological repair of periodontal tissues. With this in mind, enlightened from the research targeting the fabrication of laminar structures such as liver and kidney with heterotypic stratification of cell sheets, we proposed a novel possible strategy based on self-assembly approach, which is akin to the physiological phenomenon that occurs during organogenesis, to enhance complete reconstruction of functional complex periodontium-organ systems. We assumed that in this strategy, using the intrinsic capacity of monodispersed cells to self-assemble into a microtissue such as a 3D spheroid, bilayered cell pellet constructs comprising calcified bone-forming cell pellets (i.e., BMMSCs) and cementum/PDL-forming cell pellets (i.e., PDLSCs) would be fabricated in vitro in a tissue-mimicking way and then implanted into periodontal defects. We hypothesize that this novel strategy might open new options to reconstruct extended periodontal defects and then achieve the ultimate goal of predictable and complete regeneration of the periodontium. [source] Establishment of Three-Dimensional Tissue-engineered Bone Constructs Under Microgravity-simulated ConditionsARTIFICIAL ORGANS, Issue 2 2010Fang Jin Abstract Bone constructs have been grown in vitro with use of isolated cells, biodegradable polymer scaffolds, and bioreactors. In our work, the relationships between the composition and mechanical properties of engineered bone constructs were studied by culturing bone marrow mesenchymal stem cells (BMSCs) on ceramic bovine bone scaffolds in different environments: static flasks and dynamic culture system in rotating vessels,which was a National Aeronautics and Space Administration-recommended, ground-based, microgravity-simulating system. After 15 days of cultivation, osteogenicity was determined according to DNA and alkaline phosphatase (ALP) analysis. DNA content and ALP were higher for cells grown on dynamic culture. Subsequently, the two kinds of engineered bone constructs were selected for transplantation into Sprague-Dawley rat cranial bone defects. After 24 weeks of in vivo implantation, the engineered bone constructs under dynamic culture were found to repair the defects better, with the engineered constructs showing histologically better bone connection. Thus, this dynamic system provides a useful in vitro model to construct the functional role and effects of osteogenesis in the proliferation, differentiation, and maturation of BMSCs. These findings suggest that the hydrodynamic microgravity conditions in tissue-culture bioreactors can modulate the composition, morphology, and function of the engineered bone. [source] Bone Marrow Mesenchymal Stem Cells Form Ectopic Woven Bone In Vivo Through Endochondral Bone FormationARTIFICIAL ORGANS, Issue 4 2009Sophia Chia-Ning Chang Abstract:, Autologous vascularized bone grafts, allografts, and biocompatible artificial bone substitutes each have their shortcomings. Bones regenerated using recombinant human bone morphogenetic proteins, demineralized bone powder, or combinations of these are generally small and do not meet the need. The current trend is to use tissue engineering approaches with bone marrow mesenchymal stem cells (MSCs) to generate bones of a desired size and shape. A suspension of osteogenically induced MSCs (CD11a,, CD29+, CD44+) was added to 2% alginate, gelled by mixing this combination with calcium sulfate (CaSO4 0.2 g/mL), and injected into the subcutaneous pocket in the dorsal aspect of nude mice. Cells of various concentrations (0, 10, 50, and 70 million/mL) were used. These implanted constructs were harvested at predetermined times up to 30 weeks for histology. The doubling time of bovine MSCs is 3.75 ± 1.96 days and the proliferation is rapid. Histological evaluation revealed signs of endochondrosis with woven bone deposition. The equilibrium modulus increased with time in vivo, though less than that of normal tissue. Implants seeded with 70 million cells/mL for 6 months resulted in the best formation of equilibrium modulus. This approach has several advantages: (i) obtaining MSCs is associated with low donor morbidity; (ii) MSCs proliferate rapidly in vitro, and a large number of viable cells can be obtained; and (iii) the MSC/alginate constructs can develop into bone-like nodules with high cell viability. Such a system may be useful in large-scale production of bony implants or in the repair of bony defects. The fact that endochondral bone formation led to woven bone suggests its potential feasibility in regional cell therapy. [source] Engineering of Vascular Grafts With Genetically Modified Bone Marrow Mesenchymal Stem Cells on Poly (Propylene Carbonate) GraftARTIFICIAL ORGANS, Issue 12 2006Jun Zhang Abstract:, Bone marrow mesenchymal stem cells (MSCs) have demonstrated their pluripotency to differentiate into different cell lineages and may be an alternative cell source for vascular tissue engineering. The objective of this study is to create small diameter vessels by seeding and culture of genetically modified MSCs onto a synthetic polymer scaffold produced by an electrospinning technique. A tubular scaffold (2 mm in diameter) with a microstructure of nonwoven fibers was produced by electrospinning of poly (propylene carbonate) (PPC). Rat MSCs obtained from bone marrow were expanded in culture and modified with vasculoprotective gene endothelial nitric oxide synthase (eNOS) or marker gene green fluorescent protein (GFP). These MSCs were seeded onto the electrospun fibrous grafts (internal diameter = 2 mm), and cultured in 5% CO2 at 37°C. The growth of MSCs in the scaffold was analyzed with scanning electron microscopy (SEM) and hematoxylin and eosin (H&E) staining. The gene transfer and transgenic gene expression were examined with fluorescence-activated cell sorting (FACS), immunochemical staining, reverse transcriptase-polymerase chain reaction (RT-PCR), and western blot. The production of nitric oxide (NO) by the engineered vessels was measured with an NO detection kit. Our data showed that the seeded cells integrated with the microfibers of the scaffold to form a three-dimensional cellular network, indicating a favorable interaction between this synthetic PPC scaffold with MSCs. High transduction efficiency was obtained with the use of concentrated retrovirus in the gene transfection of MSCs. The eNOS gene transcripts and protein were detected in the grafts seeded with eNOS-modified MSCs by RT-PCR and immunochemical staining. The amount of NO produced by grafts seeded with eNOS-modified MSCs was comparable to that produced by native blood vessels, and it was significantly higher than that in the grafts seeded with nonmodified MSCs. In summary, the vascular graft produced by culture of eNOS gene-modified MSCs onto the electrospun tubular scaffolds shows promising results in terms of function. The use of MSCs and therapeutic genes in tissue engineering of blood vessels could be helpful in improving vessel regeneration and patency. [source] Tissue Engineering Research in Oral Implant SurgeryARTIFICIAL ORGANS, Issue 3 2001Minoru Ueda Abstract: In this article, we introduce some of the more extensively evaluated technologies using concepts of tissue engineering. We report on hard tissue engineering and soft tissue engineering and their utility for dental implant therapy. For hard tissue engineering, we evaluated human recombinant bone morphogenetic protein-2 and marrow mesenchymal stem cells using a model of sinus augmentation procedure in rabbit. We also describe distraction osteogenesis as another category for hard tissue engineering. In addition, we evaluate soft tissue management using cultured epithelial grafting for soft tissue engineering. The results of our tissue regeneration materials and methods in this study are positive. When the tissue engineering materials are used in clinics in the future, implant surgery could be the leading field. [source] EMF acts on rat bone marrow mesenchymal stem cells to promote differentiation to osteoblasts and to inhibit differentiation to adipocytesBIOELECTROMAGNETICS, Issue 4 2010Yong Yang Abstract The use of electromagnetic fields (EMFs) to treat nonunion fractures developed from observations in the mid-1900s. Whether EMF directly regulates the bone marrow mesenchymal stem cells (MSCs), differentiating into osteoblasts or adipocytes, remains unknown. In the present study, we investigated the roles of sinusoidal EMF of 15,Hz, 1,mT in differentiation along these separate lineages using rat bone marrow MSCs. Our results showed that EMF promoted osteogenic differentiation of the stem cells and concurrently inhibited adipocyte formation. EMF increased alkaline phosphatase (ALP) activity and mineralized nodule formation, and stimulated osteoblast-specific mRNA expression of RUNX2, ALP, BMP2, DLX5, and BSP. In contrast, EMF decreased adipogenesis and inhibited adipocyte-specific mRNA expression of adipsin, AP-2, and PPAR,2, and also inhibited protein expression of PPAR,2. These observations suggest that commitment of MSCs into osteogenic or adipogenic lineages is influenced by EMF. Bioelectromagnetics 31:277,285, 2010. © 2009 Wiley-Liss, Inc. [source] Cell proliferation of human bone marrow mesenchymal stem cells on biodegradable microcarriers enhances in vitro differentiation potentialCELL PROLIFERATION, Issue 5 2010L.-Y. Sun Objectives:, For reasons of provision of highly-specific surface area and three-dimensional culture, microcarrier culture (MC) has garnered great interest for its potential to expand anchorage-dependent stem cells. This study utilizes MC for in vitro expansion of human bone marrow mesenchymal stem cells (BMMSCs) and analyses its effects on BMMSC proliferation and differentiation. Materials and methods:, Effects of semi-continuous MC compared to control plate culture (PC) and serial bead-to-bead transfer MC (MC bead-T) on human BMMSCs were investigated. Cell population growth kinetics, cell phenotypes and differentiation potential of cells were assayed. Results:, Maximum cell density and overall fold increase in cell population growth were similar between PCs and MCs with similar starting conditions, but lag period of BMMSC growth differed substantially between the two; moreover, MC cells exhibited reduced granularity and higher CXCR4 expression. Differentiation of BMMSCs into osteogenic and adipogenic lineages was enhanced after 3 days in MC. However, MC bead-T resulted in changes in cell granularity and lower osteogenic and adipogenic differentiation potential. Conclusions:, In comparison to PC, MC supported expansion of BMMSCs in an up-scalable three-dimensional culture system using a semi-continuous process, increasing potential for stem cell homing ability and osteogenic and adipogenic differentiation. [source] Microtubule-interacting drugs induce moderate and reversible damage to human bone marrow mesenchymal stem cellsCELL PROLIFERATION, Issue 4 2009H. Polioudaki Objectives:, This study aimed to investigate molecular and cellular changes induced in human bone marrow mesenchymal stem cells (hMSCs) after treatment with microtubule-interacting agents and to estimate damage to the bone marrow microenvironment caused by chemotherapy. Materials and methods:, Using an in vitro hMSC culture system and biochemical and morphological approaches, we studied the effect of nocodazole and taxol® on microtubule and nuclear envelope organization, tubulin and p53 synthesis, cell cycle progression and proliferation and death of hMSCs isolated from healthy donors. Results and conclusions:, Both nocodazole and taxol reduced hMSC proliferation and induced changes in the microtubular network and nuclear envelope morphology and organization. However, they exhibited only a moderate effect on cell death and partial arrest of hMSCs at G2 but not at M phase of the cell cycle. Both agents induced expression of p53, exclusively localized in abnormally shaped nuclei, while taxol, but not nocodazole, increased synthesis of ,-tubulin isoforms. Cell growth rates and microtubule and nuclear envelope organization gradually normalized after transfer, in drug-free medium. Our data indicate that microtubule-interacting drugs reversibly inhibit proliferation of hMSCs; additionally, their cytotoxic action and effect on microtubule and nuclear envelope organization are moderate and reversible. We conclude that alterations in human bone marrow cells of patients under taxol chemotherapy are transient and reversible. [source] | |||||||||||||