| Perspectives of Clinical Stem Cell Therapy in the Treatment of Musculoskeletal Diseases in Germany.
February 6, 2010 at 9:06 AM
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| | Perspectives of Clinical Stem Cell Therapy in the Treatment of Musculoskeletal Diseases in Germany. Z Orthop Unfall. 2010 Jan 28; Authors: Kasten P, Bernstein P, Biewener A, Bornhäuser M, Duda G, Gaissmaier C, Nöth U, Pfüller B, Reinhardt J, Zwipp H, Günther KP AIM: The treatment of large bone defects remains a challenge for the orthopaedic surgeon. Regenerative therapies with the use of mesenchymal stem cells (MSC) may provide an alternative to autogenous bone transplantation, callus distraction or the use of allografts. MATERIAL AND METHODS: On the occasion of an expert workshop of the German Society for Orthopaedic and Trauma Surgery, a literature search regarding studies with the use of MSC was performed to evaluate its potential for future clinical studies. Furthermore, the legislative requirements were examined. RESULTS: Various IN VITRO and animal studies showed the benefit of MSC in bone regeneration. However, there are sparse data from clinical studies. Due to recent legislative changes there are several regulatory demands to meet if clinical studies are performed with MSC. CONCLUSIONS: For further evaluation of the role of MSC in the treatment of bone defects there is a need for clinical trials. The current pap! er provides some assistance for the successful application for clinical trials with MSC. Planning and performance of these studies may require early consultation with the regulatory authorities and cooperation of research centres in order to obtain authorisation for the evaluation of MSC. Preclinical data have to be obtained according to good laboratory practice with equivalent protocols that will be used in the clinical trials. In the latter the implementation of the guidelines for good clinical practice are mandatory. PMID: 20135615 [PubMed - as supplied by publisher] | | |
| Autologous stem cell transplantation in autoimmune and rheumatic diseases: from the molecular background to clinical applications.
February 6, 2010 at 9:06 AM
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| | Autologous stem cell transplantation in autoimmune and rheumatic diseases: from the molecular background to clinical applications. Scand J Rheumatol. 2010;39(1):1-11 Authors: Szodoray P, Varoczy L, Szegedi G, Zeher M Autoimmune diseases have a multifactorial origin. Because of disturbances of the immune system, autoreactive T and B cells target self-antigens, leading to permanent organ damage. Despite novel therapeutic protocols, the disease course is chronic and in many instances the outcome is lethal. The efficacy of stem cell therapy has been observed in autoimmune animal models and in autoimmune diseases related to haematological abnormalities. Although the therapy is more than 30 years old, its broad spread has been delayed by the serious side-effects due to the conditioning treatments based on oncological protocols. Evaluation of the data of patients who have undergone autologous stem cell therapy reinforced the view that protocols used for conditioning treatments, mostly causing lymphoablation, and procedures carried out in specialist centres significantly reduced mortality, with an almost optimal therapeutical efficacy. New, multicentre investigations have been launche! d to compare the efficacy of various protocols. In this review, we summarize certain aspects of the molecular background of autologous stem cell transplantation and also depict the response to therapy in various autoimmune and rheumatic diseases. PMID: 20132064 [PubMed - in process] | | |
| Isolation and cultivation of human keratinocytes from skin or plucked hair for the generation of induced pluripotent stem cells.
February 6, 2010 at 6:59 AM
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| | Isolation and cultivation of human keratinocytes from skin or plucked hair for the generation of induced pluripotent stem cells. Nat Protoc. 2010 Feb;5(2):371-82 Authors: Aasen T, Belmonte JC The ease of generating induced pluripotent stem (iPS) cells, and possibly their properties after reprogramming, depends on the origin of the somatic cell starting population. Reprogramming of keratinocytes is both faster and more efficient compared with fibroblasts, although more care is required when isolating, culturing and infecting these cells. In this study, we describe detailed protocols using both feeder-dependent and defined serum- and feeder-free conditions for culturing human keratinocytes from foreskin samples and punch biopsies, as well as how to isolate keratinocytes from plucked hair. We further describe culture techniques and approaches to efficiently infect and reprogram these cells for the purpose of generating iPS cells. The procedure of deriving keratinocytes takes 10-14 d, whereas reprogramming and the appearance of iPS cell colonies that can be isolated and established requires another 3-4 weeks. PMID: 20134422 [PubMed - in process] | | |
| Hypoxic Regulation of Nucleus Pulposus Cell Survival. From Niche to Notch.
February 6, 2010 at 6:59 AM
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| | Hypoxic Regulation of Nucleus Pulposus Cell Survival. From Niche to Notch. Am J Pathol. 2010 Feb 4; Authors: Risbud MV, Schipani E, Shapiro IM This minireview examines the role of hypoxia, and hypoxia inducible factors (HIF-1 and HIF-2), in regulating the metabolism, function, and fate of cells of the nucleus pulposus in the intervertebral disk. We focus on the mechanisms by which both these hypoxia-sensitive transcription factors influence energy metabolism, radical dismutation, and expression of survival proteins. In addition, we discuss how cells of the nucleus respond to a number of hypoxia-sensitive proteins, including galectin-3, Akt, and VEGF. Where applicable, these discussions are extended to include the impact of these molecules and hypoxia on degenerating resident cells in the intervertebral niche. Finally, because the notch signaling pathway is responsive to hypoxia, we speculate that in the intervertebral niche, notch proteins participate in the regulation of disk precursor cell proliferation and differentiation. We predict that knowledge of each of these interactive proteins within the disk! niche could be used to enhance renewal and promote differentiation and function of cells of the nucleus pulposus. PMID: 20133815 [PubMed - as supplied by publisher] | | |
| Human and mouse adipose-derived cells support feeder-independent induction of pluripotent stem cells.
February 6, 2010 at 6:59 AM
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| | Human and mouse adipose-derived cells support feeder-independent induction of pluripotent stem cells. Proc Natl Acad Sci U S A. 2010 Feb 3; Authors: Sugii S, Kida Y, Kawamura T, Suzuki J, Vassena R, Yin YQ, Lutz MK, Berggren WT, Izpisúa Belmonte JC, Evans RM Although adipose tissue is an expandable and readily attainable source of proliferating, multipotent stem cells, its potential for use in regenerative medicine has not been extensively explored. Here we report that adult human and mouse adipose-derived stem cells can be reprogrammed to induced pluripotent stem (iPS) cells with substantially higher efficiencies than those reported for human and mouse fibroblasts. Unexpectedly, both human and mouse iPS cells can be obtained in feeder-free conditions. We discovered that adipose-derived stem cells intrinsically express high levels of pluripotency factors such as basic FGF, TGFbeta, fibronectin, and vitronectin and can serve as feeders for both autologous and heterologous pluripotent cells. These results demonstrate a great potential for adipose-derived cells in regenerative therapeutics and as a model for studying the molecular mechanisms of feeder-free iPS generation and maintenance. PMID: 20133714 [PubMed - as supplied by publisher] | | |
| The role of SAP97 in synaptic glutamate receptor dynamics.
February 6, 2010 at 6:59 AM
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| | The role of SAP97 in synaptic glutamate receptor dynamics. Proc Natl Acad Sci U S A. 2010 Feb 3; Authors: Howard MA, Elias GM, Elias LA, Swat W, Nicoll RA Proteins of the PSD-95-like membrane-associated guanylate kinase (PSD-MAGUK) family are vital for trafficking AMPA receptors (AMPARs) to synapses, a process necessary for both basal synaptic transmission and forms of synaptic plasticity. Synapse-associated protein 97 (SAP97) exhibits protein interactions, such as direct interaction with the GluA1 AMPAR subunit, and subcellular localization (synaptic, perisynaptic, and dendritic) unique within this protein family. Due in part to the lethality of the germline knockout of SAP97, this protein's role in synaptic transmission and plasticity is poorly understood. We found that overexpression of SAP97 during early development traffics AMPARs and NMDA receptors (NMDARs) to synapses, and that SAP97 rescues the deficits in AMPAR currents normally seen in PSD-93/-95 double-knockout neurons. Mature neurons that have experienced the overexpression of SAP97 throughout development exhibit enhanced AMPAR and NMDAR currents, as wel! l as faster NMDAR current decay kinetics. In loss-of-function experiments using conditional SAP97 gene deletion, we recorded no deficits in glutamatergic transmission or long-term potentiation. These results support the hypothesis that SAP97 is part of the machinery that traffics glutamate receptors and compensates for other PSD-MAGUKs in knockout mouse models. However, due to functional redundancy, other PSD-MAGUKs can presumably compensate when SAP97 is conditionally deleted during development. PMID: 20133708 [PubMed - as supplied by publisher] | | |
| Regenerative Medicine Special Feature: Supramolecular design of self-assembling nanofibers for cartilage regeneration.
February 6, 2010 at 6:59 AM
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| | Regenerative Medicine Special Feature: Supramolecular design of self-assembling nanofibers for cartilage regeneration. Proc Natl Acad Sci U S A. 2010 Feb 1; Authors: Shah RN, Shah NA, Del Rosario Lim MM, Hsieh C, Nuber G, Stupp SI Molecular and supramolecular design of bioactive biomaterials could have a significant impact on regenerative medicine. Ideal regenerative therapies should be minimally invasive, and thus the notion of self-assembling biomaterials programmed to transform from injectable liquids to solid bioactive structures in tissue is highly attractive for clinical translation. We report here on a coassembly system of peptide amphiphile (PA) molecules designed to form nanofibers for cartilage regeneration by displaying a high density of binding epitopes to transforming growth factor beta-1 (TGFbeta-1). Growth factor release studies showed that passive release of TGFbeta-1 was slower from PA gels containing the growth factor binding sites. In vitro experiments indicate these materials support the survival and promote the chondrogenic differentiation of human mesenchymal stem cells. We also show that these materials can promote regeneration of articular cartilage in a full thickne! ss chondral defect treated with microfracture in a rabbit model with or even without the addition of exogenous growth factor. These results demonstrate the potential of a completely synthetic bioactive biomaterial as a therapy to promote cartilage regeneration. PMID: 20133666 [PubMed - as supplied by publisher] | | |
| Regenerative Medicine Special Feature: Engineered vascularized bone grafts.
February 6, 2010 at 6:59 AM
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| | Regenerative Medicine Special Feature: Engineered vascularized bone grafts. Proc Natl Acad Sci U S A. 2010 Feb 2; Authors: Tsigkou O, Pomerantseva I, Spencer JA, Redondo PA, Hart AR, O'Doherty E, Lin Y, Friedrich CC, Daheron L, Lin CP, Sundback CA, Vacanti JP, Neville C Clinical protocols utilize bone marrow to seed synthetic and decellularized allogeneic bone grafts for enhancement of scaffold remodeling and fusion. Marrow-derived cytokines induce host neovascularization at the graft surface, but hypoxic conditions cause cell death at the core. Addition of cellular components that generate an extensive primitive plexus-like vascular network that would perfuse the entire scaffold upon anastomosis could potentially yield significantly higher-quality grafts. We used a mouse model to develop a two-stage protocol for generating vascularized bone grafts using mesenchymal stem cells (hMSCs) from human bone marrow and umbilical cord-derived endothelial cells. The endothelial cells formed tube-like structures and subsequently networks throughout the bone scaffold 4-7 days after implantation. hMSCs were essential for stable vasculature both in vitro and in vivo; however, contrary to expectations, vasculature derived from hMSCs briefly cul! tured in medium designed to maintain a proliferative, nondifferentiated state was more extensive and stable than that with hMSCs with a TGF-beta-induced smooth muscle cell phenotype. Anastomosis occurred by day 11, with most hMSCs associating closely with the network. Although initially immature and highly permeable, at 4 weeks the network was mature. Initiation of scaffold mineralization had also occurred by this period. Some human-derived vessels were still present at 5 months, but the majority of the graft vasculature had been functionally remodeled with host cells. In conclusion, clinically relevant progenitor sources for pericytes and endothelial cells can serve to generate highly functional microvascular networks for tissue engineered bone grafts. PMID: 20133604 [PubMed - as supplied by publisher] | | |
| Towards organ printing: engineering an intra-organ branched vascular tree.
February 6, 2010 at 6:59 AM
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| | Towards organ printing: engineering an intra-organ branched vascular tree. Expert Opin Biol Ther. 2010 Mar;10(3):409-20 Authors: Visconti RP, Kasyanov V, Gentile C, Zhang J, Markwald RR, Mironov V Importance of the field: Effective vascularization of thick three-dimensional engineered tissue constructs is a problem in tissue engineering. As in native organs, a tissue-engineered intra-organ vascular tree must be comprised of a network of hierarchically branched vascular segments. Despite this requirement, current tissue-engineering efforts are still focused predominantly on engineering either large-diameter macrovessels or microvascular networks. Areas covered in this review: We present the emerging concept of organ printing or robotic additive biofabrication of an intra-organ branched vascular tree, based on the ability of vascular tissue spheroids to undergo self-assembly. What the reader will gain: The feasibility and challenges of this robotic biofabrication approach to intra-organ vascularization for tissue engineering based on organ-printing technology using self-assembling vascular tissue spheroids including clinically relevantly vascular cell sources! are analyzed. Take home message: It is not possible to engineer 3D thick tissue or organ constructs without effective vascularization. An effective intra-organ vascular system cannot be built by the simple connection of large-diameter vessels and microvessels. Successful engineering of functional human organs suitable for surgical implantation will require concomitant engineering of a 'built in' intra-organ branched vascular system. Organ printing enables biofabrication of human organ constructs with a 'built in' intra-organ branched vascular tree. PMID: 20132061 [PubMed - in process] | | |
| Silk fibroin/chitosan-hyaluronic acid versus silk fibroin scaffolds for tissue engineering: promoting cell proliferations in vitro.
February 6, 2010 at 6:43 AM
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| | Silk fibroin/chitosan-hyaluronic acid versus silk fibroin scaffolds for tissue engineering: promoting cell proliferations in vitro. J Mater Sci Mater Med. 2010 Feb 5; Authors: Chung TW, Chang YL The feasibility of silk fibroin protein (SF) scaffolds for tissue engineering applications to promote cell proliferation has been demonstrated, as well as the ability to mimic natural extra-cellular matrix (ECM), SF/chitosan (CS), a polysaccharide, scaffolds for tissue engineering. However, the response of cells to SF/CS-hyaluronic acid (SF/CS-HA) scaffolds has not been examined, which this study attempts to do and then compares those results with those of SF scaffolds. SF/CS-HA microparticles were fabricated to produce scaffolds in order to examine the proliferations of human dermal fibroblasts (HDF) in the scaffolds. Positive zeta potentials and ATR-FTIR spectra confirmed the co-existence of SF and CS-HA in SF/CS-HA microparticles. HDF proliferated well and migrated into SF/CS-HA scaffolds for around 160 mum in depth, as well as those in SF scaffolds after 7 days of cultivation, as observed using confocal microscopy. Interestingly, HDF grown in SF/CS-HA scaffold! s had a markedly higher cell density than that in SF ones. Additionally, MTT assay revealed that the growth rates of HDF in SF/CS-HA scaffolds significantly exceeded (P < 0.01, n = 5) those in scaffolds of SF and SF/CS. The daily glucose consumptions and lactate formations, metabolic parameters, of HDF grown in SF/CS-HA and SF/CS scaffolds were significantly higher (P < 0.01, n = 3) than those in SF ones in most culturing days. Results of this study suggest that SF/CS-HA scaffolds have better cell responses for tissue engineering applications than SF ones. PMID: 20135206 [PubMed - as supplied by publisher] | | |
| Tissue engineering approach to repair abdominal wall defects using cell-seeded bovine tunica vaginalis in a rabbit model.
February 6, 2010 at 6:43 AM
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| | Tissue engineering approach to repair abdominal wall defects using cell-seeded bovine tunica vaginalis in a rabbit model. J Mater Sci Mater Med. 2010 Feb 5; Authors: Ayele T, Zuki AB, Noorjahan BM, Noordin MM The aim of this study was to engineer skeletal muscle tissue for repair abdominal wall defects. Myoblast were seeded onto the scaffolds and cultivated in vitro for 5 days. Full thickness abdominal wall defects (3 x 4 cm) were created in 18 male New Zealand white rabbits and randomly divided into two equal groups. The defects of the first group were repaired with myoblast-seeded-bovine tunica vaginalis whereas the second group repaired with non-seeded-bovine tunica vaginalis and function as a control. Three animals were sacrificed at 7th, 14th, and 30th days of post-implantation from each group and the explanted specimens were subjected to macroscopic and microscopic analysis. In every case, seeded scaffolds have better deposition of newly formed collagen with neo-vascularisation than control group. Interestingly, multinucleated myotubes and myofibers were only detected in cell-seeded group. This study demonstrated that myoblast-seeded-bovine tunica vaginalis can b! e used as an effective scaffold to repair severe and large abdominal wall defects with regeneration of skeletal muscle tissue. PMID: 20135201 [PubMed - as supplied by publisher] | | |
| Hypoxic Regulation of Nucleus Pulposus Cell Survival. From Niche to Notch.
February 6, 2010 at 6:43 AM
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| | Hypoxic Regulation of Nucleus Pulposus Cell Survival. From Niche to Notch. Am J Pathol. 2010 Feb 4; Authors: Risbud MV, Schipani E, Shapiro IM This minireview examines the role of hypoxia, and hypoxia inducible factors (HIF-1 and HIF-2), in regulating the metabolism, function, and fate of cells of the nucleus pulposus in the intervertebral disk. We focus on the mechanisms by which both these hypoxia-sensitive transcription factors influence energy metabolism, radical dismutation, and expression of survival proteins. In addition, we discuss how cells of the nucleus respond to a number of hypoxia-sensitive proteins, including galectin-3, Akt, and VEGF. Where applicable, these discussions are extended to include the impact of these molecules and hypoxia on degenerating resident cells in the intervertebral niche. Finally, because the notch signaling pathway is responsive to hypoxia, we speculate that in the intervertebral niche, notch proteins participate in the regulation of disk precursor cell proliferation and differentiation. We predict that knowledge of each of these interactive proteins within the disk! niche could be used to enhance renewal and promote differentiation and function of cells of the nucleus pulposus. PMID: 20133815 [PubMed - as supplied by publisher] | | |
| Low molecular weight silk fibroin increases alkaline phosphatase and type I collagen expression in MG63 cells.
February 6, 2010 at 6:43 AM
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| | Low molecular weight silk fibroin increases alkaline phosphatase and type I collagen expression in MG63 cells. BMB Rep. 2010 Jan;43(1):52-6 Authors: Kim JY, Choi JY, Jeong JH, Jang ES, Kim AS, Kim SG, Kweon HY, Jo YY, Yeo JH Silk fibroin, produced by the silkworm Bombyx mori, has been widely studied as a scaffold in tissue engineering. Although it has been shown to be slowly biodegradable, cellular responses to degraded silk fibroin fragments are largely unknown. In this study, silk fibroin was added to MG-63 cell cultures, and changes in gene expression in the MG-63 cells were screened by DNA microarray analysis. Genes showing a significant (2-fold) change were selected and their expression changes confirmed by quantitative RT-PCR and western blotting. DNA microarray results showed that alkaline phosphatase (ALP), collagen type-I alpha-1, fibronectin, and transforming growth factor-beta1 expressions significantly increased. The effect of degraded silk fibroin on osteoblastogenic gene expression was confirmed by observing up-regulation of ALP activity in MG-63 cells. The finding that small fragments of silk fibroin are able to increase the expression of osteoblastogenic genes suggests! that controlled degradation of silk fibroin might accelerate new bone formation. [BMB reports 2010; 43(1): 52-56]. PMID: 20132736 [PubMed - in process] | | |
| Towards organ printing: engineering an intra-organ branched vascular tree.
February 6, 2010 at 6:43 AM
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| | Towards organ printing: engineering an intra-organ branched vascular tree. Expert Opin Biol Ther. 2010 Mar;10(3):409-20 Authors: Visconti RP, Kasyanov V, Gentile C, Zhang J, Markwald RR, Mironov V Importance of the field: Effective vascularization of thick three-dimensional engineered tissue constructs is a problem in tissue engineering. As in native organs, a tissue-engineered intra-organ vascular tree must be comprised of a network of hierarchically branched vascular segments. Despite this requirement, current tissue-engineering efforts are still focused predominantly on engineering either large-diameter macrovessels or microvascular networks. Areas covered in this review: We present the emerging concept of organ printing or robotic additive biofabrication of an intra-organ branched vascular tree, based on the ability of vascular tissue spheroids to undergo self-assembly. What the reader will gain: The feasibility and challenges of this robotic biofabrication approach to intra-organ vascularization for tissue engineering based on organ-printing technology using self-assembling vascular tissue spheroids including clinically relevantly vascular cell sources! are analyzed. Take home message: It is not possible to engineer 3D thick tissue or organ constructs without effective vascularization. An effective intra-organ vascular system cannot be built by the simple connection of large-diameter vessels and microvessels. Successful engineering of functional human organs suitable for surgical implantation will require concomitant engineering of a 'built in' intra-organ branched vascular system. Organ printing enables biofabrication of human organ constructs with a 'built in' intra-organ branched vascular tree. PMID: 20132061 [PubMed - in process] | | |
| A Multipotent Neural Crest Derived Progenitor Cell Population is Resident within the Oral Mucosa Lamina Propria.
February 6, 2010 at 6:43 AM
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| | A Multipotent Neural Crest Derived Progenitor Cell Population is Resident within the Oral Mucosa Lamina Propria. Stem Cells Dev. 2010 Feb 4; Authors: Davies LC, Locke M, Webb RD, Roberts JT, Langley M, Thomas DW, Archer CW, Stephens P Wounds within the oral mucosa, similarly to foetal wounds, exhibit rapid healing with reduced scarring. We hypothesised that a progenitor population resident within the oral mucosal lamina propria (OMLP) contributes to this preferential healing. Progenitor cells (PC) were reliably isolated from the OMLP by differential adhesion to fibronectin. Isolated colonies originating from a single cell demonstrated a rapid initial phase of proliferation, completing in excess of 50 population doublings before entering cellular senescence. These data were supported by the expression of active telomerase within both developing colonies and expanded clones as assessed by immunocytochemistry (ICC) and Quantitative Telomeric Repeat Amplification Protocol. FACS analysis confirmed expression of the stem cell markers CD44, CD90, CD105 and CD166, but negative expression of CD34 and CD45 ruling out a haematopoietic or fibrocyte origin for these progenitors. A neural crest origin was co! nfirmed by increased colony forming efficiency in the presence of Jagged 1 and the expression of a number of neural crest markers within the developing colonies by ICC and serially passaged clones by Western blotting. The multipotency of this novel PC population was demonstrated by differentiation of the cells down both mesenchymal (chondrogenic, osteoblastic and adipogenic) and neuronal (neuron and Schwann-like cells) cell lineages. This paper reports for the first time, the isolation and characterisation of a novel, clonally derived PC population resident within the OMLP. The attributes of this adult stem cell population and its accessibility lends itself to future therapeutic applications. PMID: 20132052 [PubMed - as supplied by publisher] | | |
| Modulating endochondral ossification of multipotent stromal cells for bone regeneration.
February 6, 2010 at 6:43 AM
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| | Modulating endochondral ossification of multipotent stromal cells for bone regeneration. Tissue Eng Part B Rev. 2010 Feb 4; Authors: Gawlitta D, Farrell E, Malda J, Creemers L, Alblas J, Dhert W For years it has been recognized that engineering of large bone constructs will be feasible only if the hurdle of vascularization is overcome. Attempts to engineer bone tissue have predominantly focused on the intramembranous (direct) bone formation. A relatively new and most likely more physiological approach in this line is endochondral bone formation, comprising an intermediate cartilaginous stage. Cartilage in nature is an avascular tissue and its cells are equipped to survive the poor oxygenation and nutritional conditions inherent to implanted tissues. Subsequent terminal differentiation (hypertrophy) of the chondrocytes initiates the formation of a mineralized matrix that will then be converted into bone. Through this mechanism, our long bones grow and most fractures heal through the process of secondary fracture healing. The feasibility of the attractive concept of endochondral bone tissue engineering has already been shown. Most emphasis has gone to the m! ultipotent stromal cells (MSCs) due their great potential for expansion and differentiation and immuno-privileged nature. The present review will focus on the promises and current status of this new field. Furthermore, potent modulators of endochondral bone tissue engineering, including oxygen tension and mechanical stimuli, will be discussed. PMID: 20131956 [PubMed - as supplied by publisher] | | |
| Tailored Electroactive and Quantitative Ligand Density Microarrays Applied to Stem Cell Differentiation.
February 6, 2010 at 6:43 AM
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| | Tailored Electroactive and Quantitative Ligand Density Microarrays Applied to Stem Cell Differentiation. J Am Chem Soc. 2010 Feb 4; Authors: Luo W, Chan EW, Yousaf MN The ability to precisely control the interactions between materials and mammalian cells at the molecular level is crucial to understanding the fundamental chemical nature of how the local environment influences cellular behavior as well as for developing new biomaterials for a range of biotechnological and tissue engineering applications. In this report, we develop and apply for the first time a quantitative electroactive microarray strategy that can present a variety of ligands with precise control over ligand density to study human mesenchymal stem cell (hMSC) differentiation on transparent surfaces with a new method to quantitate adipogenic differentiation. We found that both the ligand composition and ligand density influence the rate of adipogenic differentiation from hMSC's. Furthermore, this new analytical biotechnology method is compatible with other biointerfacial characterization technologies (surface plasmon resonance, mass spectrometry) and can also be! applied to investigate a range of protein-ligand or cell-material interactions for a variety of systems biology studies or cell behavior based assays. PMID: 20131824 [PubMed - as supplied by publisher] | | |
| Culture effects of epidermal growth factor (EGF) and basic fibroblast growth factor (bFGF) on cryopreserved human adipose-derived stromal/stem cell proliferation and adipogenesis.
February 6, 2010 at 6:43 AM
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| | Culture effects of epidermal growth factor (EGF) and basic fibroblast growth factor (bFGF) on cryopreserved human adipose-derived stromal/stem cell proliferation and adipogenesis. J Tissue Eng Regen Med. 2009 Oct;3(7):553-61 Authors: Hebert TL, Wu X, Yu G, Goh BC, Halvorsen YD, Wang Z, Moro C, Gimble JM Previous studies have demonstrated that EGF and bFGF maintain the stem cell properties of proliferating human adipose-derived stromal/stem cells (hASCs) in vitro. While the expansion and cryogenic preservation of isolated hASCs are routine, these manipulations can impact their proliferative and differentiation potential. This study examined cryogenically preserved hASCs (n = 4 donors), with respect to these functions, after culture with basic fibroblast growth factor (bFGF) and epidermal growth factor (EGF) at varying concentrations (0-10 ng/ml). Relative to the control, cells supplemented with EGF and bFGF significantly increased proliferation by up to three-fold over 7-8 days. Furthermore, cryopreserved hASCs expanded in the presence of EGF and bFGF displayed increased oil red O staining following adipogenic induction. This was accompanied by significantly increased levels of several adipogenesis-related mRNAs: aP2, C/EBPalpha, lipoprotein lipase (LPL), PPARgamm! a and PPARgamma co-activator-1 (PGC1). Adipocytes derived from EGF- and bFGF-cultured hASCs exhibited more robust functionality based on insulin-stimulated glucose uptake and atrial natriuretic peptide (ANP)-stimulated lipolysis. These findings indicate that bFGF and EGF can be used as culture supplements to optimize the proliferative capacity of cryopreserved human ASCs and their adipogenic differentiation potential. PMID: 19670348 [PubMed - indexed for MEDLINE] | | |
| Isolation of a Highly Myogenic CD34-Negative Subset of Human Skeletal Muscle Cells Free of Adipogenic Potential.
February 6, 2010 at 6:31 AM
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| | Isolation of a Highly Myogenic CD34-Negative Subset of Human Skeletal Muscle Cells Free of Adipogenic Potential. Stem Cells. 2010 Feb 4; Authors: Pisani DF, Dechesne CA, Sacconi S, Delplace S, Belmonte N, Cochet O, Clement N, Wdziekonski B, Villageois AP, Butori C, Bagnis C, Di Santo JP, Kurzenne JY, Desnuelle C, Dani C The differentiation of multipotent cells into undesirable lineages is a significant risk factor when performing cell therapy. In muscular diseases, myofiber loss can be associated with progressive fat accumulation that is one of the primary factors leading to decline of muscular strength. Therefore, to avoid any contribution of injected multipotent cells to fat deposition, we have searched for a highly myogenic but non-adipogenic muscle-derived cell population.We show that the myogenic marker CD56, which is the gold standard for myoblast-based therapy, was unable to separate muscle cells into myogenic and adipogenic fractions. Conversely, using the stem cell marker CD34, we were able to sort two distinct populations, CD34(+) and CD34(-), which have been thoroughly characterized in vitro as well as in vivo using an immunodeficient Rag2(-/-)gamma(c) (-/-) mouse model of muscle regeneration with or without adipose deposition. Our results demonstrate that both populat! ions have equivalent capacities for in vitro amplification. The CD34(+) cells and CD34(-) cells exhibit equivalent myogenic potential, but only the CD34(-) population fails to differentiate into adipocytes in vitro as well as in vivo after transplantation into regenerative fat muscle.These data indicate that the muscle-derived cells constitute an heterogeneous population of cells with various differentiation potential. The simple CD34 sorting allows isolation of myogenic cells with no adipogenic potential and therefore could be of high interest for cell therapy when fat is accumulated in diseased muscle. PMID: 20135684 [PubMed - as supplied by publisher] | | | |
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