| Scripps research team develops technique to determine ethnic origin of stem cell lines
December 29, 2009 at 6:52 pm
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| Cultured and freshly isolated adipose tissue-derived cells: fat years for cardiac stem cell therapy.
December 29, 2009 at 8:22 am
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| | Cultured and freshly isolated adipose tissue-derived cells: fat years for cardiac stem cell therapy. Eur Heart J. 2009 Dec 25; Authors: Sánchez PL, Sanz-Ruiz R, Fernández-Santos ME, Fernández-Avilés F PMID: 20037147 [PubMed - as supplied by publisher] |
| Stem Cell Transplantation for Neurometabolic and Neurodegenerative Diseases.
December 29, 2009 at 8:22 am
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| | Stem Cell Transplantation for Neurometabolic and Neurodegenerative Diseases. Neuropharmacology. 2009 Dec 23; Authors: Shihabuddin LS, Aubert I Over the last decade, the potential for therapeutic use of stem cell transplantation for cell replacement or as cellular vectors for gene delivery for neurometabolic and neurodegenerative diseases has received a great deal of interest. There has been substantial progress in our understanding of stem cell biology. Potential applications of cell-mediated therapy include direct cell replacement or protection and repair of the host nervous system. Given the complexities of the cellular organization of the nervous system, especially in diseased states, it seems that using stem cells as cellular vectors to prevent or ameliorate neurological disorders rather than cell replacement and the regrowth of damaged circuitry is more likely to succeed in the near term. Recent success in the treatment of lysosomal storage diseases with genetically modified stem cells support this notion. In Alzheimer's and Parkinson's diseases, stem cell therapy is at its early stages and data generated in animal models and clinical trials using other cell types suggest that a combination of gene and stem cell therapy may be an optimal therapeutic paradigm. PMID: 20036262 [PubMed - as supplied by publisher] |
| Cardiac stem and progenitor cell identification: Different markers for the same cell?
December 29, 2009 at 6:52 am
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| | Cardiac stem and progenitor cell identification: Different markers for the same cell? Front Biosci (Schol Ed). 2010;2:641-52 Authors: Ellison GM, Galuppo V, Vicinanza C, Aquila I, Waring CD, Leone A, Indolfi C, Torella D For a long time the heart has been considered a terminally differentiated organ without any regenerative potential. The latter has been classically based on the terminally differentiated nature of cardiomyocytes and the absence of a pool of tissue-specific stem cells. This view has been radically changed due to the discovery of resident cardiac stem and progenitor cells in the adult mammalian heart. However, at minimum, 5 apparently different cardiac stem and/or progenitor cell types have been described so far. Thus, we have changed from a view of the heart as a static tissue to an organ with the highest number of tissue-specific stem cell populations. Most likely, the different putative adult cardiac stem and progenitor cells represent different developmental and/or physiological stages of a unique resident adult cardiac stem cell. Notably, it is not yet known the origin of all these cells. A better understanding of the origin, biology and physiology of the myocardial stem and progenitor cells will impact the development of regenerative medicine as an effective therapy for heart disease and failure. PMID: 20036974 [PubMed - in process] |
| Vitamin C Enhances the Generation of Mouse and Human Induced Pluripotent Stem Cells.
December 29, 2009 at 6:52 am
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| | Vitamin C Enhances the Generation of Mouse and Human Induced Pluripotent Stem Cells. Cell Stem Cell. 2009 Dec 24; Authors: Esteban MA, Wang T, Qin B, Yang J, Qin D, Cai J, Li W, Weng Z, Chen J, Ni S, Chen K, Li Y, Liu X, Xu J, Zhang S, Li F, He W, Labuda K, Song Y, Peterbauer A, Wolbank S, Redl H, Zhong M, Cai D, Zeng L, Pei D Somatic cells can be reprogrammed into induced pluripotent stem cells (iPSCs) by defined factors. However, the low efficiency and slow kinetics of the reprogramming process have hampered progress with this technology. Here we report that a natural compound, vitamin C (Vc), enhances iPSC generation from both mouse and human somatic cells. Vc acts at least in part by alleviating cell senescence, a recently identified roadblock for reprogramming. In addition, Vc accelerates gene expression changes and promotes the transition of pre-iPSC colonies to a fully reprogrammed state. Our results therefore highlight a straightforward method for improving the speed and efficiency of iPSC generation and provide additional insights into the mechanistic basis of the reprogramming process. PMID: 20036631 [PubMed - as supplied by publisher] |
| Tissue differentiation in an in vivo bioreactor: in silico investigations of scaffold stiffness.
December 29, 2009 at 6:42 am
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| | Tissue differentiation in an in vivo bioreactor: in silico investigations of scaffold stiffness. J Mater Sci Mater Med. 2009 Dec 27; Authors: Khayyeri H, Checa S, Tägil M, O'Brien FJ, Prendergast PJ Scaffold design remains a main challenge in tissue engineering due to the large number of requirements that need to be met in order to create functional tissues in vivo. Computer simulations of tissue differentiation within scaffolds could serve as a powerful tool in elucidating the design requirements for scaffolds in tissue engineering. In this study, a lattice-based model of a 3D porous scaffold construct derived from micro CT and a mechano-biological simulation of a bone chamber experiment were combined to investigate the effect of scaffold stiffness on tissue differentiation inside the chamber. The results indicate that higher scaffold stiffness, holding pore structure constant, enhances bone formation. This study demonstrates that a lattice approach is very suitable for modelling scaffolds in mechano-biological simulations, since it can accurately represent the micro-porous geometries of scaffolds in a 3D environment and reduce computational costs at the same time. PMID: 20037774 [PubMed - as supplied by publisher] |
| The linker-free covalent attachment of collagen to plasma immersion ion implantation treated polytetrafluoroethylene and subsequent cell-binding activity.
December 29, 2009 at 6:42 am
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| | The linker-free covalent attachment of collagen to plasma immersion ion implantation treated polytetrafluoroethylene and subsequent cell-binding activity. Biomaterials. 2009 Dec 23; Authors: Bax DV, McKenzie DR, Weiss AS, Bilek MM It is desirable that polymers used for the fabrication of prosthetic implants promote biological functions such as cellular adhesion, differentiation and viability. In this study, we have used plasma immersion ion implantation (PIII) to modify the surface of polytetrafluoroethylene (PTFE), thereby modulating the binding mechanism of collagen. The amount of collagen bound to the polymer surface following PIII-treatment was similar to that bound by non-covalent physisorption. In a manner consistent with previous enzyme and tropoelastin binding data, the collagen bound to the PIII-treated PTFE surface was resistant to sodium dodecyl sulfate (SDS) elution whilst collagen bound to the untreated surface was fully removed. This demonstrates the capability of PIII-treated surfaces to covalently attach collagen without employing chemical linking molecules. Only the collagen bound to the PIII-treated PTFE surface supported human dermal fibroblast attachment and spreading. This indicates that collagen on the PIII-treated surface possesses increased adhesive activity as compared to that on the untreated surface. Cell adhesion was inhibited by EDTA when the collagen was bound to PIII-treated PTFE, as expected for integrin involvement. Additionally this adhesion was sensitive to the conformation of the bound collagen. Increased actin cytoskeletal assembly was observed on cells spreading onto collagen-coated PIII-treated PTFE compared to the collagen-coated untreated PTFE. These data demonstrate the retention of collagen's biological properties following its attachment to PIII-treated PTFE, suggesting advantages for tissue engineering and prosthetic design. PMID: 20035993 [PubMed - as supplied by publisher] |
| Physicochemical and biological activity study of genipin-crosslinked chitosan scaffolds prepared by using supercritical carbon dioxide for tissue engineering applications.
December 29, 2009 at 6:42 am
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| | Physicochemical and biological activity study of genipin-crosslinked chitosan scaffolds prepared by using supercritical carbon dioxide for tissue engineering applications. Int J Biol Macromol. 2009 Dec 22; Authors: Rinki K, Dutta PK The present study deals with the preparation of porous chitosan scaffolds by using a greener technique i.e., supercritical carbon dioxide (sc.CO(2)). 0.2M chitosan (CS) solution in aq. acetic acid was treated with 4% (w/v) genipin solution; the resulting hydrogels were subjected to solvent-exchange prior to the final treatment procedures. Their morphology, pore structure, and physical properties were characterized by thermal analysis, X-ray diffractogram (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM) and the specific surface areas and porosimetry of scaffolds were determined by using N(2) adsorption. The biological activity of scaffolds was investigated by immersing them into 1.5X simulated body fluid (SBF) and cellular attachment study was assessed using Alamar Blue assay by seeding MG63 osteoblastic cells onto the scaffolds. The sc.CO(2) assisted chitosan scaffold prepared by using green chemistry approach is highly pure and bioactive and can be served as a potential material for tissue engineering applications. PMID: 20035784 [PubMed - as supplied by publisher] |
| The Repair of Critical Size Bone Defects using Expedited, Autologous BMP-2 Gene Activated Fat Implants.
December 29, 2009 at 6:42 am
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| | The Repair of Critical Size Bone Defects using Expedited, Autologous BMP-2 Gene Activated Fat Implants. Tissue Eng Part A. 2009 Dec 26; Authors: Betz OB, Betz VM, Abdulazim A, Penzkofer R, Schmitt B, Schröder C, Mayer-Wagner S, Augat P, Jansson V, Müller P The repair of bone defects can be induced experimentally with Bone Morphogenetic Protein-2 (BMP-2) producing fat derived stem cells, but this ex vivo tissue engineering method requires the isolation and long-term culture of autologous cells. In order to develop an expedited bone repair strategy, we transferred BMP-2 cDNA directly to autologous fat tissue fragments which were held in culture for only 24 hours prior to implantation. We evaluated the ability of such gene activated fat grafts to regenerate large segmental bone defects in rats. Fat tissue was harvested from two of 35 male Fischer 344 rats used for this study. The fat tissue fragments were incubated with an adenoviral vector carrying the cDNA encoding either BMP-2 or Green Flourescent Protein (GFP), or they remained unmodified. According to their group affiliation, the segmental femoral bone defects of 33 rats were filled press fit with either BMP-2 activated fat tissue or GFP transduced fat tissue or unmodified fat tissue. Another control group remained untreated. Femora were evaluated by radiographs, micro-computed tomography (microCT), biomechanical torsional testing and histology. Radiographically and histologically, 100% of the femora treated with BMP-2 activated fat grafts were bridged at 6 weeks after surgery. The femora of this group exceeded the bone volume and the biomechanical stability of intact, contralateral femora. Control defects receiving no treatment, unmodified fat tissue or GFP transduced fat were filled with fibrous or adipose tissue, as evaluated by histology. The use of BMP-2 gene activated fat tissue grafts represents an expedited and effective bone repair strategy that does not require the extraction and expansion of stem cells. PMID: 20035609 [PubMed - as supplied by publisher] |
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