|  |  |  | | | | | TE-RegenMed-StemCell feed | | | | | | | | | | | | | | | | | | | General Overview of the Seventh International Symposium on Stem Cell Therapy and Cardiovascular Innovations. J Cardiovasc Transl Res. 2010 Dec 4; Authors: Gutiérrez E, Sanz-Ruiz R, Alvarez EV, Villa A, Fernández L, Vázquez S, Lorenzo J, Fernández-Santos E, Sánchez PL, Fernández-Avilés F The Seventh International Symposium on Stem Cell Therapy and Cardiovascular Innovations was held in Madrid on the 6th and 7th of May 2010. Gathering for the seventh consecutive year the most relevant researchers and opinion leaders on cardiovascular cell therapy, it has become the most important worldwide event on this field. A comprehensive review of the last developments on cell therapy, surgery for heart failure and tissue engineering was made, and the results of three clinical trials were reported. The Symposium was dedicated to the memory of Professor Helmut Drexler. PMID: 21132470 [PubMed - as supplied by publisher] | | | | | | | | | | | | | | | | | | | | | | | | | The Implications of Human Stem Cell Differentiation to Endothelial Cell via Fluid Shear Stress in Cardiovascular Regenerative Medicine: A Review. Curr Pharm Des. 2010 Dec 3; Authors: Tan A, Sumpio BE, Lee S, Seifalian AM Stem cell therapy heralds a new chapter in cardiovascular regenerative medicine. Cardiovascular implants are often used in both surgery and interventional cardiology. Cardiovascular stents are utilized in percutaneous coronary interventions (PCI), and are classified as either bare metal stents (BMS) or drug-eluting stents (DES). Although DES might decrease the risk of vascular restenosis, there are complications (e.g. thrombosis) associated with it as well. Many new and novel composite materials are increasingly being developed along the premise of mobilizing and attracting endogenous stem cells to home-in and differentiate into a confluent layer of endothelial cell around the vessel wall. One of the main forces acting on cells in a blood vessel wall is fluid shear stress. Fluid shear stress is vital in establishing the vasculature of the embryo, and different shear stress patterns have been both implicated in maintaining vascular physiology, and also associated with certain pathological conditions. Recent evidence suggests that via a plethora of mechanosensors and mechanotransduction signaling pathways, stem cells differentiate into endothelial cells when exposed to fluid shear stress. Here we review the current knowledge pertaining to the roles that mechanosensors and mechanotransducers play in stem cell differentiation into endothelial cells via fluid shear stress, and its implications for pharmacological applications and cardiovascular implants in the realm of regenerative medicine. PMID: 21128890 [PubMed - as supplied by publisher] | | | | | | | | | | | | | | | | | | | | | | | | What exactly in California law bars non-citizens from becoming the chair of the $3 billion stem cell agency? Especially since its president is an Australian.
We asked Don Gibbons, CIRM's chief communications officer, about the issue last Friday morning. So far we have not heard back from him despite two additional queries. This morning we tried James Harrison, outside counsel to the board.
Our | | | | | | | | | | | | | | | | | | | | | | | | | General Overview of the Seventh International Symposium on Stem Cell Therapy and Cardiovascular Innovations. J Cardiovasc Transl Res. 2010 Dec 4; Authors: Gutiérrez E, Sanz-Ruiz R, Alvarez EV, Villa A, Fernández L, Vázquez S, Lorenzo J, Fernández-Santos E, Sánchez PL, Fernández-Avilés F The Seventh International Symposium on Stem Cell Therapy and Cardiovascular Innovations was held in Madrid on the 6th and 7th of May 2010. Gathering for the seventh consecutive year the most relevant researchers and opinion leaders on cardiovascular cell therapy, it has become the most important worldwide event on this field. A comprehensive review of the last developments on cell therapy, surgery for heart failure and tissue engineering was made, and the results of three clinical trials were reported. The Symposium was dedicated to the memory of Professor Helmut Drexler. PMID: 21132470 [PubMed - as supplied by publisher] | | | | | | | | | | | | | | | | | | | | | | | | | Establishment of an aging model of Sca-1+ hematopoietic stem cell and studies on its relative biological mechanisms. In Vitro Cell Dev Biol Anim. 2010 Dec 4; Authors: Zhou Y, Yang B, Yao X, Wang Y The objective of this study is to establish the aging model of murine hematopoietic stem cell (HSC) ex vitro and investigate its relative biological mechanism, aimed to build the foundation for searching the methods to delaying HSC aging. Sca-1(+)HSC were isolated and purified from murine bone marrow mono-nucleated cell by magnetic-activated cell sorting. The purity of separated cells was analyzed by flow cytometry (FCM) and the expression of Sca-1 was detected by immunofluorescence. Sca-1(+)HSC induced aging by tert-butylhydroperoxide (t-BHP, final concentration of 100 μmol/L) for 6 h to establish the murine HSC aging model in vitro. Biological characteristics of aging HSC were evaluated by mixed hematopoietic progenitor cell culture in vitro, cell cycle assay and senescence-associated β-galactosidase (SA-β-gal) cytochemical staining. Telomere length and telomerase activity were detected by southern blotting and telomere repeat amplification protocol-polymerase chain reaction (TRAP-PCR) augmentation. The expressions of p16(INK4a), P19(Arf), P53, P21(Cip1/Waf1) mRNA were detected by reverse transcription (RT)-PCR. The purity of separated Sca-1(+) HSC was 87.2% and the survival of Sca-1(+) HSC was 96~99%. After 6 h cocultured with 100 μmol/L t-BHP, the ability of aging Sca-1(+) HSC to form mixed hematopoietic progenitor colony, self-renewal and multi-differentiation were decreased significantly. The number of aging Sca-1(+) HSC entered G1 phase of the cell cycle and the percentage of positive cells expressed SA-β-gal increased significantly. The telomere length shortened and the telomerase activity decreased. The expression of p16(INK4a), p19(Arf), p53, P21(Cip1/Waf1) mRNA increased. The t-BHP can induce Sca-1(+) HSC senescence in vitro. The signal transduction pathways of p16(INK4a)-retinoblastoma and P19(Arf)-Mdm2-P53-P21(Cip1/Waf1) may play key roles in the Sca-1(+) HSC senescence induced by t-BHP. PMID: 21132465 [PubMed - as supplied by publisher] | | | | | | | | | | | | | | | | | | | | | | | | | Alpinia galanga extracts downregulate interleukin-1β-induced matrix metalloproteinases expression in human synovial fibroblasts. In Vitro Cell Dev Biol Anim. 2010 Dec 4; Authors: Pothacharoen P, Choocheep K, Phitak T, Pompimon W, Kongtawelert P Alpinia galanga has been used as alternative medicine for anti-rheumatic activities. However, the precise action of the extract on arthritic diseases is not yet fully understood. In this study, we investigated the effects of A. galanga extracts on the expression of genes involved in catabolic activities in an interleukin-1β (IL-1β)-induced human synovial fibroblast as an inflammatory model. Confluent primary human synovial fibroblasts were treated for 24 h with A. galanga hexane extracts in the presence of recombinant human IL-1β. MMPs in the culture medium were monitored by gelatin zymography. Total RNA was isolated from the cell lysate and analyzed via semi-quantitative RT-PCR. After treatment with A. galanga extracts, MMP-2 activity in the culture medium was significantly reduced. In addition, MMP-1, MMP-3, MMP-13, and Cox-2 expression were downregulated. These data suggest that the decrease of gene expression and production of MMPs in synovial fibroblasts against inflammatory stimuli could be due to the effects of the A. galanga extracts. Therefore, A. galanga extracts might be a promising therapeutic agent for arthritis. PMID: 21132464 [PubMed - as supplied by publisher] | | | | | | | | | | | | | | | | | | | | | | | | | Immobilization and bioactivity evaluation of FGF-1 and FGF-2 on powdered silicon-doped hydroxyapatite and their scaffolds for bone tissue engineering. J Mater Sci Mater Med. 2010 Dec 4; Authors: Feito MJ, Lozano RM, Alcaide M, Ramírez-Santillán C, Arcos D, Vallet-Regí M, Portolés MT Fibroblast growth factors (FGFs) are polypeptides that control the proliferation and differentiation of various cell types including osteoblasts. FGFs are also strong inducers of angiogenesis, necessary to obtain oxygen and nutrients during tissue repair. With the aim to incorporate these desirable FGF biological properties into bioceramics for bone repair, silicon substituted hydroxyapatites (Si-HA) were used as materials to immobilize bioactive FGF-1 and FGF-2. Thus, the binding of these growth factors to powdered Si-HA and Si-HA scaffolds was carried out efficiently in the present study and both FGFs maintained its biological activity on osteoblasts after its immobilization. The improvement of cell adhesion and proliferation onto Si-HA scaffolds suggests the potential utility of these FGF/scaffolds for bone tissue engineering. PMID: 21132351 [PubMed - as supplied by publisher] | | | | | | | | | | | | | | | | | | | | | | | | | Saloplastic Macroporous Polyelectrolyte Complexes: Cartilage Mimics. Macromolecules. 2010 Oct 26;43(20):8656-8663 Authors: Hariri HH, Schlenoff JB Complexes of sodium poly(4-styrenesulfonate) (NaPSS) and poly(diallyldimethylammonium chloride) (PDADMAC) were formed on mixing equimolar solutions in high salt concentration. Under ultracentrifugal fields, the complex precipitates were transformed into compact polyelectrolyte complexes (CoPECs), which showed extensive porosity. The mechanical properties of CoPECS make them attractive for bioimplants and tissue engineering applications. Free NaPSS chains in the closed pores of CoPECs create excess osmotic pressure, which controls the pore size and contributes to the mechanical resistance of the material. The mechanical properties of CoPECs, modulated by the ionic strength of the doping medium, were studied by uniaxial tensile testing and the stress-strain data were fit to a three-element Maxwell model which revealed at least two regimes of stress relaxation. PMID: 21132107 [PubMed - as supplied by publisher] | | | | | | | | | | | | | | | | | | | | | | | | | Hydrolysis and biomineralization of porous PLA microspheres and their influence on cell growth. Colloids Surf B Biointerfaces. 2010 Nov 17; Authors: Shi X, Jiang J, Sun L, Gan Z Poly(lactic acid) (PLA) microspheres have great potential in bone tissue engineering. However, their applications have been limited by surface and bulk properties such as hydrophobicity, lack of cell recognition sites and acidic degradation products. Apatite is a mineral which can effectively promote the adhesion and growth of bone cells. In this study, the bonelike mineral, carbonate apatite, was successfully used to functionalize porous PLA microspheres by a biomimetic mineralization method. To improve apatite formation, porous PLA microspheres were first selectively hydrolyzed in NaOH solution to increase the density of polar anionic groups on the surface, and then immersed in simulated body fluid for biomineralization. The morphology, composition, and phase structure of bioactive mineral grown on the original and hydrolyzed PLA microspheres were analyzed and compared quantitatively. The results showed that the hydrolysis which took place on the PLA microspheres enhanced the nucleation and growth of apatite. MG-63 cells attached well and spread actively on the mineralized PLA microspheres, indicating their strong potential in bone tissue engineering. PMID: 21131184 [PubMed - as supplied by publisher] | | | | | | | | | | | | | | | | | | | | | | | | | Robust MeO(2)MA/vinyl-4,6-diamino-1,3,5-triazine copolymer hydrogels-mediated reverse gene transfection and thermo-induced cell detachment. Biomaterials. 2010 Dec 3; Authors: Tang L, Yang Y, Bai T, Liu W We have fabricated a robust temperature sensitive hydrogel by photoinitiated copolymerization of 2-(2-methoxyethoxy)ethyl methacrylate (MeO(2)MA), 2-vinyl-4,6-diamino-1,3,5-triazine (VDT) and crosslinker polyethylene glycol diacrylate (PEGDA). It was shown that self-hydrogen bondings of VDT moieties in the bulk considerably strengthened the mechanical properties of gels, which was dependent on the weight ratio of MeO(2)/VDT and the initial monomer concentration; the VDT motifs on the surface could efficiently bind DNA for reverse gene transfection. On this soft-wet platform, gene expression lasted 7 days and the re-treated gels could be reused for new cycle of transfection. The gene modified cells could be detached by thermo-triggered switchable surface hydrophilicity of PMEO(2)MA in hydrogel. MTT assay showed low cytotoxicity of hydrogels. The results suggested that this type of mechanically strong H-bonded and thermoresponsive hydrogels hold a great potential as an integrated functional soft-wet platform for the unharmful harvest of gene modified seed cells for tissue engineering or as implantable scaffold for gene therapy and regenerative medicine applications. PMID: 21131046 [PubMed - as supplied by publisher] | | | | | | | | | | | | | | | | | | | | | | | | | Effect of flow perfusion conditions in the chondrogenic differentiation of bone marrow stromal cells cultured onto starch based biodegradable scaffolds. Acta Biomater. 2010 Dec 2; Authors: Gonçalves A, Costa P, Rodrigues MT, Dias IR, Reis RL, Gomes ME Cartilage tissue engineering (TE) typically involves the combination of a 3D biodegradable polymeric support material, with primary condrocytes or other cell type able to differentiate into chondrocytes. Another important factor is the culture environment, which cell-material constructs are submitted to/accommodated. Different bioreactors have been introduced in TE approaches to provide specific culturing environments that might promote and accelerate cells potential for chondrogenic differentiation and enhance the production of cartilage extracellular matrix. The aim of the present study was to study the chondrogenic differentiation of goat bone marrow cells (GBMCs) under flow perfusion culture conditions. For that purpose, GBMCs were seeded into starch-polycaprolactone (SPCL) fiber mesh scaffolds and cultured in a flow perfusion bioreactor for up to 28 days using culture medium supplemented with TGF-β1. The tissue engineered constructs were characterized after several end points (7, 14, 21 and 28 days) by histological staining and immunocytochemistry analysis, as well as by GAGs and ALP quantification assays. Also, the expression of typical chondrogenic markers was assessed by real time RT-PCR analysis. In general, the results obtained suggest that flow perfusion microenvironment favors the chondrogenic potential of GBMCs. PMID: 21130906 [PubMed - as supplied by publisher] | | | | | | | | | | | | | | | | | | | | | | | | | Fabrication of Porous Chitosan Scaffolds for Soft Tissue Engineering by Using Dense Gas CO(2). Acta Biomater. 2010 Dec 2; Authors: Ji C, Annabi N, Khademhosseini A, Dehghani F The aim of this study was to investigate the feasibility of fabricating porous crosslinked chitosan hydrogels in an aqueous phase using dense gas CO(2) as a foaming agent. Highly porous chitosan hydrogels were formed by using glutaraldehyde (GA) and genipin (GP) as crosslinkers. The method developed here eliminates the formation of a skin layer, the use of surfactants or other toxic reagents for generating porosity in hydrogels. The chitosan hydrogel scaffolds had an average pore diameter between 30 μm and 40 μm. The operating pressure had negligible effect on the pore characteristics of chitosan hydrogels. Temperature, reaction period, type of biopolymer and crosslinker had significant impact on the pore size and characteristics of the hydrogel produced by dense gas CO(2). Scanning electron microscopy (SEM) and histological analysis confirmed that the resulting porous structures allowed fibroblasts seeded on these scaffolds to proliferate into three-dimensional (3D) structure of chitosan hydrogels. Live/dead staining and MTS analysis demonstrated that fibroblast cells proliferated over seven days. The fabricated hydrogels exhibited comparable mechanical strength and swelling ratio and are potentially useful for soft tissue engineering applications such as skin and cartilage regeneration. PMID: 21130905 [PubMed - as supplied by publisher] | | | | | | | | | | | | | | | | | | | | | | | | | Mathematical Modeling of Polymer Erosion: Consequences for Drug Delivery. Int J Pharm. 2010 Dec 2; Authors: Sackett CK, Narasimhan B Bioerodible polymers have been extensively used as carriers for drug delivery and as scaffolds for tissue engineering. The ability to model and predict erosion behavior can enable the rational design and optimization of biomaterials for various biomedical applications in vivo. This review examines critically the current approaches in mathematical modeling of the erosion of synthetic polymers. The models are classified broadly based on whether they use phenomenological, probabilistic, or empirical approaches. An analysis of the various physical, chemical, and biological factors affecting polymer erosion and the classes of bioerodible polymers to which these analyses have been applied are discussed. The key features and assumptions associated with each of the models are described, and information is provided on the limitations of the models and the various approaches. The review concludes with several directions for future models of polymer erosion. PMID: 21130849 [PubMed - as supplied by publisher] | | | | | | | | | | | | | | | | | | | | | | | | | 3D systems delivering VEGF to promote angiogenesis for tissue engineering. J Control Release. 2010 Dec 2; Authors: Rieux AD, Ucakar B, Mupendwa BP, Colau D, Feron O, Carmeliet P, Préat V In most cases, vascularization is the first requirement to achieve tissue regeneration. The delivery from implants of angiogenic factors, like VEGF, has been widely investigated for establishing a vascular network within the developing tissue. In this report, we investigated if encapsulation of VEGF in nanoparticles could enhance angiogenesis in vivo as compared to free VEGF when incorporated into two different types of 3D matrices: Matrigel™ hydrogels and PLGA scaffolds. Negatively charged nanoparticles encapsulating VEGF were obtained with a high efficiency by complex formation with dextran sulfate and coacervation by chitosan. After 2weeks, encapsulation reduced VEGF release from hydrogels from 30% to 1% and increased VEGF release from scaffolds from 20% to 30% in comparison with free VEGF. VEGF encapsulation consistently improved angiogenesis in vivo with both type of 3D matrices: up to 7.5- to 3.5-times more endothelial and red blood cells were observed, respectively, into hydrogels and scaffolds. Hence, encapsulation in nanoparticles enhanced VEGF efficiency by protection and controlled release from 3D implants. Encapsulation and incorporation of VEGF into 3D implants that, in addition to sustaining cell infiltration and organization, will stimulate blood vessel is a promising approach for tissue regeneration engineering. PMID: 21130820 [PubMed - as supplied by publisher] | | | | | | | | | | | | | | | | | | | | | | | | | Fabrication and characterization of tunable polysaccharide hydrogel blends for neural repair. Acta Biomater. 2010 Dec 1; Authors: Zuidema JM, Pap MM, Jaroch DB, Morrison FA, Gilbert RJ Hydrogels are an important class of biomaterials that have the potential to be used as three-dimensional tissue engineering scaffolds for regenerative medicine. This is especially true in the central nervous system, where neurons do not have the ability to regenerate due to the prohibitory local environment following injury. Hydrogels can fill an injury site, replacing the growth-prohibiting environment with a more growth permissive one. In this study, dextran and chitosan were incorporated into a methylcellulose and agarose hydrogel blend. This created several thermally sensitive polysaccharide hydrogel blends that had tunable mechanical and surface charge properties. Cortical neurons were cultured on the hydrogels to determine the blend that had the greatest neuron compatibility. Our results show that softer, more positively charged polysaccharide hydrogel blends allow for greater neuron attachment and neurite extension, showing their promise as CNS regeneration scaffolds. PMID: 21130187 [PubMed - as supplied by publisher] | | | | | | | | | | | | | | | | | | | | | | | | | Purpose-driven biomaterials research in liver-tissue engineering. Trends Biotechnol. 2010 Dec 1; Authors: Ananthanarayanan A, Narmada BC, Mo X, McMillian M, Yu H Bottom-up engineering of microscale tissue ("microtissue") constructs to recapitulate partially the complex structure-function relationships of liver parenchyma has been realized through the development of sophisticated biomaterial scaffolds, liver-cell sources, and in vitro culture techniques. With regard to in vivo applications, the long-lived stem/progenitor cell constructs can improve cell engraftment, whereas the short-lived, but highly functional hepatocyte constructs stimulate host liver regeneration. With regard to in vitro applications, microtissue constructs are being adapted or custom-engineered into cell-based assays for testing acute, chronic and idiosyncratic toxicities of drugs or pathogens. Systems-level methods and computational models that represent quantitative relationships between biomaterial scaffolds, cells and microtissue constructs will further enable their rational design for optimal integration into specific biomedical applications. PMID: 21129798 [PubMed - as supplied by publisher] | | | | | | | | | | | | | | | | | | | | | | | | | Bone regeneration and stem cells. J Cell Mol Med. 2010 Dec 3; Authors: Arvidson K, Abdallah BM, Applegate LA, Baldini N, Cenni E, Gomez-Barrena E, Granchi D, Kassem M, Konttinen YT, Mustafa K, Pioletti DP, Sillat T, Finne-Wistrand A This invited review covers research areas of central importance for orthopedic and maxillofacial bone tissue repair, including normal fracture healing and healing problems, biomaterial scaffolds for tissue engineering, mesenchymal and fetal stem cells, effects of sex steroids on mesenchymal stem cells, use of platelet rich plasma for tissue repair, osteogenesis and its molecular markers. A variety of cells in addition to stem cells, as well as advances in materials science to meet specific requirements for bone and soft tissue regeneration by addition of bioactive molecules, are discussed. PMID: 21129153 [PubMed - as supplied by publisher] | | | | | | | | | | | | | | | | | | | | | | | | | A Tissue Engineering Approach for Prenatal Closure of Myelomeningocele: Comparison Of Gelatin Sponge And Microsphere Scaffolds And Bioactive Protein Coatings. Tissue Eng Part A. 2010 Dec 5; Authors: Watanabe M, Li H, Roybal JL, Santore MT, Radu A, Jo JI, Kaneko M, Tabata Y, Flake A Myelomeningocele (MMC) is a common and devastating malformation. As an alternative to fetal surgical repair, tissue engineering has the potential to provide a less invasive approach for tissue coverage applicable at an earlier stage of gestation. We have previously evaluated the use of gelatin hydrogel composites composed of gelatin sponges and sheets as a platform for tissue coverage of the MMC defect in the retinoic acid induced fetal rat model of MMC. In the current study, we compare our previous composite with gelatin microspheres as a scaffold for tissue ingrowth and cellular adhesion within the amniotic fluid environment. We also examine the relative efficacy of various bioactive protein coatings on the adhesion of amniotic fluid cells to the construct within the amniotic cavity. We conclude from this study, that gelatin microspheres are as effective as gelatin sponges as a scaffold for cellular ingrowth and amniotic fluid cell adhesion and that Collagen type I and fibronectin coatings enhance amniotic fluid cell adhesion to the gelatin based scaffolds. These findings support the potential for the development of a tissue engineered injectable scaffold that could be applied by ultrasound guided injection, much earlier and less invasively than sponge or sheet based composites. PMID: 21128864 [PubMed - as supplied by publisher] | | | | | | | | | | | | | | | | | | | | | | | | | 2010 Lifetime Achievement Award of Tissue Engineering and Regenerative Medicine International Society-North America: Arnold I. Caplan, Ph.D. Tissue Eng Part A. 2010 Dec 3; Authors: PMID: 21128820 [PubMed - as supplied by publisher] | | | | | | | | | |  | |  | |  |
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