|  |  |  | | | | | TERMSC | | | | | | | | | | | | | | | | | | | Monitoring oxygen uptake in 3D tissue engineering scaffolds by phosphorescence quenching microscopy. Biotechnol Prog. 2010 Sep;26(5):1494-500 Authors: Guaccio A, Netti PA Measuring oxygen concentration in three-dimensional cultures, without interfering with cellular activities, is a fundamental request of tissue engineering research. Among the other techniques, it has been demonstrated that phosphorescence quenching microscopy (PQM) represents a valid tool for the detection of oxygen concentration in 3D environments. Indeed, it is not invasive, with high spatial and temporal resolution, and, once calibrated, it is not affected by the presence of extracellular matrix components and other environmental factors. In this work, a description of the PQM experimental set up for oxygen measurements in solutions and 3D polymer-based cellular constructs is provided. Moreover, the advantage and the limits in the use of this technique are critically discussed to provide a technical note for future applications. © 2010 American Institute of Chemical Engineers Biotechnol. Prog., 2010. PMID: 20945496 [PubMed - in process] | | | | | | | | | | | | | | | | | | | | | | | | | Neutrophil differentiation from human-induced pluripotent stem cells. J Cell Physiol. 2010 Oct 13; Authors: Morishima T, Watanabe KI, Niwa A, Fujino H, Matsubara H, Adachi S, Suemori H, Nakahata T, Heike T Induced pluripotent stem (iPS) cells are of potential value not only for regenerative medicine, but also for disease investigation. The present study describes the development of a neutrophil differentiation system from human iPS cells (hiPSCs) and the analysis of neutrophil function and differentiation. The culture system used consisted of the transfer of hiPSCs onto OP9 cells and their culture with vascular endothelial growth factor (VEGF). After 10 days, TRA 1-85(+)CD34(+)VEGF receptor-2 (VEGFR-2)(high) cells were sorted and co-cultured with OP9 cells in the presence of hematopoietic cytokines for 30 days. Floating cells were collected and subjected to morphological and functional analysis. These hiPSC-derived neutrophils were similar to peripheral blood mature neutrophils in morphology, contained functional neutrophil specific granules, and were equipped with the basic functions such as phagocytosis, superoxide production, and chemotaxis. In the process of differentiation, myeloid cells appeared sequentially from immature myeloblasts to mature segmented neutrophils. Expression patterns of surface antigen, transcription factors and granule proteins during differentiation were also similar to those of granulopoiesis in normal bone marrow. In conclusion, differentiation of mature neutrophils from hiPSCs was successfully induced in a similar process to normal granulopoiesis using an OP9 co-culture system. This system may be applied to elucidate the pathogenesis of various hematological diseases that affect neutrophils. J. Cell. Physiol. © 2010 Wiley-Liss, Inc. PMID: 20945397 [PubMed - as supplied by publisher] | | | | | | | | | | | | | | | | | | | | | | | | | Mechanistic insights into reprogramming to induced pluripotency. J Cell Physiol. 2010 Oct 13; Authors: Ho R, Chronis C, Plath K Induced pluripotent stem (iPS) cells can be generated from various embryonic or adult cell types upon expression of a set of few transcription factors, most commonly consisting of Oct4, Sox2, c-Myc and Klf4, following a strategy originally published by Takahashi and Yamanaka in 2006 (Takahashi and Yamanaka, 2006). Since iPS cells are molecularly and functionally similar to embryonic stem (ES) cells, they provide a source of patient-specific pluripotent cells for regenerative medicine and disease modeling, and therefore have generated enormous scientific and public interest. The generation of iPS cells also presents a powerful tool for dissecting mechanisms that stabilize the differentiated state and are required for the establishment of pluripotency. In this review, we discuss our current view of the molecular mechanisms underlying transcription factor-mediated reprogramming to induced pluripotency. © 2010 Wiley-Liss, Inc. PMID: 20945378 [PubMed - as supplied by publisher] | | | | | | | | | | | | | | | | | | | | | | | | | Human embryonic stem cell proliferation and differentiation as parameters to evaluate developmental toxicity. J Cell Physiol. 2010 Oct 13; Authors: Pal R, M MK, Das AK, Bhonde R In vitro models based on embryonic stem cells (ESC) are highly promising for improvement of predictive toxicology screening in humans. After the successful validation of Embryonic Stem Cell Test (EST) in 2001; concerns have been raised on the usage of mouse ESC and also the morphological evaluation of beating cell clusters. This requires specialized skill-sets and is highly prone to misjudgement and false positive results. To overcome these limitations, we undertook the present study incorporating improvisations over the conventional EST. Here, we explored the potential of a human ESC (hESC)- based assay to evaluate the potential toxicity of Penicillin-G, Caffeine and Hydroxyurea. Drug treatment inhibited hESC adhesion and substantially altered the morphology and viability (˜50%) of embryoid bodies (EBs). Flow cytometry analysis not only showed a significant increase of apoptotic cells in the highest doses but also induced a diverse pattern in DNA content and cell cycle distribution relative to control. Both semi-quantitative and quantitative RT-PCR studies revealed a selective down regulation of markers associated with stemness (NANOG, REX-1, SOX-2, hTERT); cardiac mesoderm (Cripto1, MEF-2C and Brachyury); hepatic endoderm (AFP, HNF-3β, HNF-4α, GATA-4 and SOX-17); and neuroectoderm (NESTIN, SOX-1, NURR1, NEFH, Synaptophysin, TH and Olig2) in a drug as well as dose dependent manner indicating abnormal differentiation. Furthermore, a decrease in the expression of AFP and GFAP proteins followed by a dose-dependent reduction in the levels of hCG-β, Progesterone-II and Estradiol hormones was demonstrated by immunocytochemistry and ECLIA respectively. This new and unique approach comprising of DNA cell cycle analysis, germ layer-specific marker expression and hormone levels as endpoints might offer a clinically relevant and commercially viable alternative for predicting in vivo developmental toxicity. J. Cell. Physiol. © 2010 Wiley-Liss, Inc. PMID: 20945368 [PubMed - as supplied by publisher] | | | | | | | | | | | | | | | | | | | | | | | | | Cell surface N-glycans mediated isolation of mouse neural stem cells. J Cell Physiol. 2010 Oct 13; Authors: Hamanoue M, Okano H The isolation of neural stem cells (NSCs) has been hampered by the lack of valid cell surface antigens on NSCs, and novel valuable markers have been proposed. Glycan (oligosaccharide chain) is a potential candidate as a marker to isolate NSCs, because the species and the combination order of saccharides in glycan generate remarkable structural diversity and specificity. At present, the expression of hundreds of glycoconjugates with glycans have been found in the NSCs; however, just a few glycan-epitopes have been identified as valuable cell surface markers. This review focused on the isolation of NSC using glycoprotein, especially complex-type N-glycans. The cell surface N-glycan mediated isolation of NSCs is therefore expected to provide a comprehensive understanding of the biologic characteristics of NSCs in the brain, and thereby help to develop novel strategies in the field of regenerative medicine. © 2010 Wiley-Liss, Inc. PMID: 20945342 [PubMed - as supplied by publisher] | | | | | | | | | | | | | | | | | | | | | | | | | Supermacroprous chitosan-agarose-gelatin cryogels: in vitro characterization and in vivo assessment for cartilage tissue engineering. J R Soc Interface. 2010 Oct 13; Authors: Bhat S, Tripathi A, Kumar A The study focuses on the synthesis of a novel polymeric scaffold having good porosity and mechanical characteristics synthesized by using natural polymers and their optimization for application in cartilage tissue engineering. The scaffolds were synthesized via cryogelation technology using an optimized ratio of the polymer solutions (chitosan, agarose and gelatin) and cross-linker followed by the incubation at sub-zero temperature (-12°C). Microstructure examination of the chitosan-agarose-gelatine (CAG) cryogels was done using scanning electron microscopy (SEM) and fluorescent microscopy. Mechanical analysis, such as the unconfined compression test, demonstrated that cryogels with varying chitosan concentrations, i.e. 0.5-1% have a high compression modulus. In addition, fatigue tests revealed that scaffolds are suitable for bioreactor studies where gels are subjected to continuous cyclic strain. In order to confirm the stability, cryogels were subjected to high frequency (5 Hz) with 30 per cent compression of their original length up to 1 × 10(5) cycles, gels did not show any significant changes in their mass and dimensions during the experiment. These cryogels have exhibited degradation capacity under aseptic conditions. CAG cryogels showed good cell adhesion of primary goat chondrocytes examined by SEM. Cytotoxicity of the material was checked by MTT assay and results confirmed the biocompatibility of the material. In vivo biocompatibility of the scaffolds was checked by the implantation of the scaffolds in laboratory animals. These results suggest the potential of CAG cryogels as a good three-dimensional scaffold for cartilage tissue engineering. PMID: 20943683 [PubMed - as supplied by publisher] | | | | | | | | | | | | | | | | | | | | | | | | | Bioengineering of living renal membranes consisting of hierarchical, bioactive supramolecular meshes and human tubular cells. Biomaterials. 2010 Oct 11; Authors: Dankers PY, Boomker JM, Huizinga-van der Vlag A, Wisse E, Appel WP, Smedts FM, Harmsen MC, Bosman AW, Meijer W, van Luyn MJ Maintenance of polarisation of epithelial cells and preservation of their specialized phenotype are great challenges for bioengineering of epithelial tissues. Mimicking the basement membrane and underlying extracellular matrix (ECM) with respect to its hierarchical fiber-like morphology and display of bioactive signals is prerequisite for optimal epithelial cell function in vitro. We report here on a bottom-up approach based on hydrogen-bonded supramolecular polymers and ECM-peptides to make an electro-spun, bioactive supramolecular mesh which can be applied as synthetic basement membrane. The supramolecular polymers used, self-assembled into nano-meter scale fibers, while at micro-meter scale fibers were formed by electro-spinning. We introduced bioactivity into these nano-fibers by intercalation of different ECM-peptides designed for stable binding. Living kidney membranes were shown to be bioengineered through culture of primary human renal tubular epithelial cells on these bioactive meshes. Even after a long-term culturing period of 19 days, we found that the cells on bioactive membranes formed tight monolayers, while cells on non-active membranes lost their monolayer integrity. Furthermore, the bioactive membranes helped to support and maintain renal epithelial phenotype and function. Thus, incorporation of ECM-peptides into electro-spun meshes via a hierarchical, supramolecular method is a promising approach to engineer bioactive synthetic membranes with an unprecedented structure. This approach may in future be applied to produce living bioactive membranes for a bio-artificial kidney. PMID: 20943265 [PubMed - as supplied by publisher] | | | | | | | | | | | | | | | | | | | | | | | | | NRSF Silencing Induces Human Amniotic Fluid-Derived Stem Cell Differentiation into Insulin-Producing Cells. Stem Cells Dev. 2010 Oct 13; Authors: Li B, Wang S, Liu H, Liu D, Zhang J, Zhang B, Yao H, Lv Y, Wang R, Chen L, Yue W, Li Y, Pei XT Islet cell replacement represents the most promising approach for the treatment of type I diabetes. However, it is limited by a shortage of pancreas donors. Here, we report that human amniotic fluid-derived stem cells (hAFSCs) can be induced to differentiate into functional insulin-producing cells by knocking down neuronal restrictive silencing factor (NRSF). In this study, lentiviral vectors were used to deliver small interference NRSF RNA (siNRSF) into hAFSCs. After infection with lentivirus containing siNRSF, hAFSCs were successfully induced to differentiate into insulin-producing cells. The differentiated siNRSF-hAFSCs expressed genes specific for islet cells, such as Pdx1, Hnf4α, Isl-1, Nkx6.1, Insulin, and Glut2. These cells also produced and released C-peptide in a glucose-responsive manner. These findings indicated that hAFSCs could be induced to differentiate into insulin-producing β-like cells by NRSF silencing. PMID: 20942606 [PubMed - as supplied by publisher] | | | | | | | | | | | | | | | | | | | | | | | | | A changing time: the International Society for Cellular Therapy embraces its industry members. Cytotherapy. 2010 Nov;12(7):853-856 Authors: Deans R, Gunter KC, Allsopp T, Bonyhadi M, Burger SR, Carpenter M, Clark T, Cox CS, Driscoll D, Field E, Huss R, Lardenoije RX, Lodie TA, Mason C, Neubiser R, Rasko JE, Rowley J, Maziarz RT Abstract The last decade has seen a dramatic rise in the development of new cellular therapeutics in a wide range of indications. There have been acceptable safety profiles reported in early studies using blood-derived and adherent stem cell products, but also an inconsistent efficacy record. Further expansion has been hindered in part by a lack of capital (both private and public) and delayed entry into the cell therapy space by large healthcare and pharmaceutical companies, those members of the industry most reliably able to initiate and maintain advanced-phase clinical trials. With recognition that the International Society for Cellular Therapy (ISCT) is uniquely positioned to serve the global translational regenerative medicine research community as a network hub for scientific standards and policy, the ISCT commissioned the establishment of an Industry Task Force (ITF) to address current and future roles for industry. The objectives of the ITF were to gather information and prioritize efforts for a new Commercialization Committee (CC) and to construct innovative platforms that would foster constructive and synergistic collaborations between industry and ISCT. Recommendations and conclusions of the ITF included that the new CC: (1) foster new relationships with therapeutic and stem cell societies, (2) foster educational workshops and forums to cross-educate and standardize practices, (3) create industry subcommittees to address priority initiatives, with clear benchmarks and global implementation, and (4) establish a framework for a greater industry community within ISCT, opening doors for industry to share the new vision for commercialization of cell therapy, emphasizing the regenerative medicine space. PMID: 20942603 [PubMed - as supplied by publisher] | | | | | | | | | | | | | | | | | | | | | | | | | Tissue-engineering bone from omentum. Nagoya J Med Sci. 2010 Aug;72(3-4):111-7 Authors: Kamei Y, Toriyama K, Takada T, Yagi S Tissue engineering of bone is an interesting field of research. Many approaches to bone tissue engineering such as from bone marrow stromal cells in vitro have been reported. Furthermore, a model of vascularized tissue-engineered bone flap has been reported. However, there has been no report of bone tissue engineering using omentum. We present a study of tissue engineering of bone from omentum in a rabbit model. The omentum, which was elevated based on the right gastroepiploic vessels, was wrapped by the periosteum from cranial bone in the abdomen of rabbits. We harvested the omentum thus wrapped 1, 2, 4, 6, 8, 12, or 24 weeks after surgery. Within 1 week after surgery, woven bone was formed and clusters of osteoblasts were observed. At 8 weeks, medullization, including the presence of granulocytes, was confirmed. This technique might prove useful for creating tissue-engineered bone flaps for reconstructive surgery. PMID: 20942265 [PubMed - in process] | | | | | | | | | | | | | | | | | | | | | | | | | Stem cell homing in musculoskeletal injury. Biomaterials. 2010 Oct 6; Authors: Fong EL, Chan CK, Goodman SB The regenerative potential of injured adult tissue suggests the physiological existence of cells capable of participating in the reparative process. Recent studies indicate that stem-like cells residing in tissues contribute to tissue repair and are replenished by precursor bone marrow-derived cells. Mesenchymal stromal cells (MSC) are among the candidates for reparative cells. These cells can potentially be mobilized into the circulation in response to injury signals and exert their reparative effects at the site of injury. Current therapies for musculoskeletal injuries pose unavoidable risks which can impede full recovery. Trafficking of MSC to the injury site and their subsequent participation in the regenerative process is thought to be a natural healing response that can be imitated or augmented by enhancing the endogenous MSC pool with exogenously administered MSC. Therefore, a promising alternative to the existing strategies employed in the treatment of musculoskeletal injuries is to reinforce the inherent reparative capacity of the body by delivering MSC harvested from the patient's own tissues to the site of injury. The aim of this review is to inform the reader of studies that have evaluated the intrinsic homing and regenerative abilities of MSC, with particular emphasis on the repair of musculoskeletal injuries. Research that supports the direct use of MSC (without in vitro differentiation into tissue-specific cells) will also be reported. Based on accruing evidence that the natural healing mechanism involves the recruitment of MSC and their subsequent reparative actions at the site of injury, as well as documented therapeutic response after the exogenous administration of MSC, the feasibility of the emerging strategy of instant stem-cell therapy will be proposed. PMID: 20933277 [PubMed - as supplied by publisher] | | | | | | | | | | | | | | | | | | | | | | | | | Concerns and Hopes for Stem Cell Therapy in Cardiology: Focus on Endothelial Progenitor Cells. Cardiovasc Hematol Disord Drug Targets. 2010 Jul 19; Authors: Ferrari R, Beltrami CA, Tavazzi L The crucial role played by the endothelium in cardiovascular disorders has been repetitively recognised. Endothelium injury has been implicated in atherosclerosis, thrombosis, hypertension and other cardiovascular diseases. Recently, however, research has undertaken a new avenue. As mature endothelial cells posses limited regenerative capacities, the interest has been switched to the circulating endothelial progenitor cells (EPCs). Indeed, the scientific community has made progress in understanding the role of EPCs in the maintenance of endothelial integrity and function as well as post natal neovascularisation. It has been suggested that these cells are able to home in the site of heart injury / damage and that they might take part in angiogenesis, giving hope for new treatment opportunities. There is evidence that reduced availability of EPCs or impairment of their function is associated with more severe CV disease and to comorbid risk factors. Different current drug regimes are able to influence bone marrow production and release of EPCs and several growth factors are considered for possible useful new therapeutic approaches. Thus, many studies into the potential use of EPCs in the clinical setting have recently been conducted with conflicting results. The goal of this review article is to discuss current therapies to regenerate new vessels and therefore to enhance myocardial function. The article overviews the search strategy and the pathophysiological aspects behind this therapy, consider the target currently under investigation and set the stage for new ideas. PMID: 20929437 [PubMed - as supplied by publisher] | | | | | | | | | | | | | | | | | | | | | | | | | Translation of science to surgery: linking emerging concepts in biological cartilage repair to surgical intervention. J Bone Joint Surg Br. 2010 Sep;92(9):1195-202 Authors: Moran CJ, Shannon FJ, Barry FP, O'Byrne JM, O'Brien T, Curtin W Orthopaedic surgery is in an exciting transitional period as modern surgical interventions, implants and scientific developments are providing new therapeutic options. As advances in basic science and technology improve our understanding of the pathology and repair of musculoskeletal tissue, traditional operations may be replaced by newer, less invasive procedures which are more appropriately targeted at the underlying pathophysiology. However, evidence-based practice will remain a basic requirement of care. Orthopaedic surgeons can and should remain at the forefront of the development of novel therapeutic interventions and their application. Progression of the potential of bench research into an improved array of orthopaedic treatments in an effective yet safe manner will require the development of a subgroup of specialists with extended training in research to play an important role in bridging the gap between laboratory science and clinical practice. International regulations regarding the introduction of new biological treatments will place an additional burden on the mechanisms of this translational process, and orthopaedic surgeons who are trained in science, surgery and the regulatory environment will be essential. Training and supporting individuals with these skills requires special consideration and discussion by the orthopaedic community. In this paper we review some traditional approaches to the integration of orthopaedic science and surgery, the therapeutic potential of current regenerative biomedical science for cartilage repair and ways in which we may develop surgeons with the skills required to translate scientific discovery into effective and properly assessed orthopaedic treatments. PMID: 20798434 [PubMed - indexed for MEDLINE] | | | | | | | | | | | | | | | | | | | | | | | | | Development of a porcine delayed wound-healing model and its use in testing a novel cell-based therapy. Int J Radiat Oncol Biol Phys. 2010 Nov 1;78(3):888-96 Authors: Hadad I, Johnstone BH, Brabham JG, Blanton MW, Rogers PI, Fellers C, Solomon JL, Merfeld-Clauss S, DesRosiers CM, Dynlacht JR, Coleman JJ, March KL PURPOSE: A delayed full-thickness wound-healing model was developed and used for examining the capacity of adipose-derived stem cells (ASCs), either alone or in platelet-rich fibrin gels, to promote healing. METHODS AND MATERIALS: Four pigs received electron beam radiation to the dorsal skin surface. Five weeks after radiation, subcutaneous fat was harvested from nonirradiated areas and processed to yield ASCs. Two weeks later, 28 to 30 full-thickness 1.5-cm(2) wounds were made in irradiated and nonirradiated skin. Wounds were treated with either saline solution, ASCs in saline solution, platelet-rich plasma (PRP) fibrin gel, ASCs in PRP, or non-autologous green fluorescence protein-labeled ASCs. RESULTS: The single radiation dose produced a significant loss of dermal microvasculature density (75%) by 7 weeks. There was a significant difference in the rate of healing between irradiated and nonirradiated skin treated with saline solution. The ASCs in PRP-treated wounds exhibited a significant 11.2% improvement in wound healing compared with saline solution. Enhancement was dependent on the combination of ASCs and PRP, because neither ASCs nor PRP alone had an effect. CONCLUSIONS: We have created a model that simulates the clinically relevant late radiation effects of delayed wound healing. Using this model, we showed that a combination of ASCs and PRP improves the healing rates of perfusion-depleted tissues, possibly through enhancing local levels of growth factors. PMID: 20708345 [PubMed - indexed for MEDLINE] | | | | | | | | | | | | | | | | | | | | | | | | | Immunogenicity and allogenicity: a challenge of stem cell therapy. J Cardiovasc Transl Res. 2009 Mar;2(1):130-8 Authors: Charron D, Suberbielle-Boissel C, Al-Daccak R As age progresses, the regenerative power of one's own pluripotent stem cells is often inadequate to sustain normal tissue function. Consequently, the incidence of chronic and degenerative diseases has significantly increased. The derivation of adult tissues and organs from a variety of stem cell sources represents the starting mark for regenerative medicine. It is currently considered a developing mean to repair, restore, maintain, or enhance organ functioning through life span. Recent advances in human embryonic stem cells (hESC) research, however, made the prospect of cell replacement therapy even more compelling and highlighted hESC as a fast track in the therapeutic hope. Among the hurdles which have been largely overlooked in the excitement over the expected benefit is the immunogenicity. Indeed, beyond the clear need to establish the safety of hESC and their derived tissues in terms of tumorogenicity and potential to transmit infections, the challenge is to overcome the immunological barriers to their transplantation. PMID: 20559977 [PubMed - indexed for MEDLINE] | | | | | | | | | | | | | | | | | | | | | | | | | Panoramic view of the Fifth International Symposium on Stem Cell Therapy and Applied Cardiovascular Biotechnology, April 2008, Madrid (Spain). J Cardiovasc Transl Res. 2009 Mar;2(1):108-13 Authors: Villa A, Sanz R, Fernandez ME, Elizaga J, Ludwig I, Sanchez PL, Fernandez-Aviles F The Fifth International Symposium on Stem Cell Therapy and Applied Cardiovascular Biotechnology was held on April 24th-25th, 2008, at the Auditorium of the High Council of Scientific Research of Spain (CSIC) in Madrid, as a continuation of a series of yearly meetings, organized in an attempt to encourage translational research in this field and facilitate a positive interaction among experts from several countries, along with industry representatives and journalists. In addition, members of the Task Force of the European Society concerning the clinical investigation of the use of autologous adult stem cells for repair of the heart gathered and discussed an update of the previous consensus, still pending of publication. In this article, we summarize some of the main topics of discussion, the state-of-the-art and latest advances in this field, and new challenges brought up for the near future. PMID: 20559974 [PubMed - indexed for MEDLINE] | | | | | | | | | | | | | | | | | | | | | | | | | Adipose tissue-derived stem cells: the friendly side of a classic cardiovascular foe. J Cardiovasc Transl Res. 2008 Mar;1(1):55-63 Authors: Sanz-Ruiz R, Santos ME, Muñoa MD, Martín IL, Parma R, Fernández PL, Fernández-Avilés F Recently, the existence of a population of stem cells located in the adipose tissue has been observed. Adipose-derived stem cells are able to differentiate into multiple cell lineages including cardiac myocytes. Hence, adipose-derived cells are emerging as a new source of adult stem cells for cardiovascular repair. In this review, we discuss the basic principles of adipose-derived stem cells (types and characteristics, obtention processes, immunophenotypic characterization, and cell potency), the initial experimental studies, and the currently ongoing clinical trials. PMID: 20559958 [PubMed - indexed for MEDLINE] | | | | | | | | | | | | | | | | | | | | | | | | | Simple surface modification of a titanium alloy with silanated zwitterionic phosphorylcholine or sulfobetaine modifiers to reduce thrombogenicity. Colloids Surf B Biointerfaces. 2010 Sep 1;79(2):357-64 Authors: Ye SH, Johnson CA, Woolley JR, Murata H, Gamble LJ, Ishihara K, Wagner WR Thrombosis and thromboembolism remain problematic for a large number of blood contacting medical devices and limit broader application of some technologies due to this surface bioincompatibility. In this study we focused on the covalent attachment of zwitterionic phosphorylcholine (PC) or sulfobetaine (SB) moieties onto a TiAl(6)V(4) surface with a single step modification method to obtain a stable blood compatible interface. Silanated PC or SB modifiers (PCSi or SBSi) which contain an alkoxy silane group and either PC or SB groups were prepared respectively from trimethoxysilane and 2-methacryloyloxyethyl phosphorylcholine (MPC) or N-(3-sulfopropyl)-N-(methacryloxyethyl)-N,N-dimethylammonium betaine (SMDAB) monomers by a hydrosilylation reaction. A cleaned and oxidized TiAl(6)V(4) surface was then modified with the PCSi or SBSi modifiers by a simple surface silanization reaction. The surface was assessed with X-ray photoelectron spectroscopy (XPS), attenuated total reflection-Fourier transform infrared spectroscopy (ATR-FTIR) and contact angle goniometry. Platelet deposition and bulk phase activation were evaluated following contact with anticoagulated ovine blood. XPS results verified successful modification of the PCSi or SBSi modifiers onto TiAl(6)V(4) based on increases in surface phosphorous or sulfur respectively. Surface contact angles in water decreased with the addition of hydrophilic PC or SB moieties. Both the PCSi and SBSi modified TiAl(6)V(4) surfaces showed decreased platelet deposition and bulk phase platelet activation compared to unmodified TiAl(6)V(4) and control surfaces. This single step modification with PCSi or SBSi modifiers offers promise for improving the surface hemocompatibility of TiAl(6)V(4) and is attractive for its ease of application to geometrically complex metallic blood contacting devices. PMID: 20547042 [PubMed - indexed for MEDLINE] | | | | | | | | | | | | | | | | | | | | | | | | | Drug reprofiling using zebrafish identifies novel compounds with potential pro-myelination effects. Neuropharmacology. 2010 Sep;59(3):149-59 Authors: Buckley CE, Marguerie A, Roach AG, Goldsmith P, Fleming A, Alderton WK, Franklin RJ Treatment of the autoimmune demyelinating disease multiple sclerosis (MS) requires therapies that both limit and repair damage. While several immunomodulatory treatments exist to limit damage there are currently no treatments that promote the regenerative process of remyelination. A rapid way of screening potential pro-remyelination compounds is therefore required. The use of larval zebrafish in a drug reprofiling screen allows rapid in vivo screening and has been used successfully in the past as an efficient way of identifying new indications for existing drugs. A novel screening platform for potential pro-myelination compounds was developed using zebrafish larvae. Two percent of compounds screened from reprofiling libraries altered oligodendrocyte lineage cell recruitment and/or proliferation, as measured by the numbers of dorsally migrated spinal cord olig2(+) cells. Selective screening identified three compounds that altered levels of myelination, as measured by whole larvae myelin basic protein (mbp) transcript levels; the src family kinase inhibitor PP2, a biogenic amine and a thioxanthene. As well as many previously unrecognised compounds, identified compounds included those with previously known effects on myelin and/or the oligodendrocyte lineage, such as a PPAR agonist, steroid hormones and src family kinase inhibitors. As well as providing methods for further assessment of potentially beneficial compounds, this screen has highlighted 25 targets that are able to alter oligodendrocyte lineage cell recruitment or proliferation and/or mbp transcript levels in vivo and are worthy of further investigation for their potential effects on remyelination. PMID: 20450924 [PubMed - indexed for MEDLINE] | | | | | | | | | | | | | | | | | | | | | | | | | Three-dimensional early retinal progenitor 3D tissue constructs derived from human embryonic stem cells. J Neurosci Methods. 2010 Jun 30;190(1):63-70 Authors: Nistor G, Seiler MJ, Yan F, Ferguson D, Keirstead HS PURPOSE: To develop three-dimensional (3D) constructs of retinal pigment epithelium (RPE) and early retina progenitor cells from human embryonic stem cells (hESCs). METHODS: 3D tissue constructs were developed by culturing hESC-derived neural retinal progenitors in a matrix on top of hESC-derived RPE cells in a cell culture insert. An osmolarity gradient maintained the nutrition of the 3D cell constructs. Cross-sections through hESC-derived tissue constructs were characterized by immunohistochemistry for various transcription factors and cell markers. RESULTS: hESC-derived tissue constructs expressed transcription factors characteristic of retinal development, such as pax6, Otx2, Chx10, retinal RAX; Brn3b (necessary for differentiation of retinal ganglion cells); and crx and nrl (role in photoreceptor development). Many cells expressed neuronal markers including nestin, beta-tubulin and microtubule-associated proteins. CONCLUSIONS: This study shows for the first time that 3D early retinal progenitor tissue constructs can be derived from hESCs. PMID: 20447416 [PubMed - indexed for MEDLINE] | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | |  | |  | |  |
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