|  |  |  | | | | | TERMSC | | | | | | | | | | | | | | | | | | | High-throughput combinatorial cell co-culture using microfluidics. Integr Biol (Camb). 2011 Apr 28; Authors: Tumarkin E, Tzadu L, Csaszar E, Seo M, Zhang H, Lee A, Peerani R, Purpura K, Zandstra PW, Kumacheva E Co-culture strategies are foundational in cell biology. These systems, which serve as mimics of in vivo tissue niches, are typically poorly defined in terms of cell ratios, local cues and supportive cell-cell interactions. In the stem cell niche, the ability to screen cell-cell interactions and identify local supportive microenvironments has a broad range of applications in transplantation, tissue engineering and wound healing. We present a microfluidic platform for the high-throughput generation of hydrogel microbeads for cell co-culture. Encapsulation of different cell populations in microgels was achieved by introducing in a microfluidic device two streams of distinct cell suspensions, emulsifying the mixed suspension, and gelling the precursor droplets. The cellular composition in the microgels was controlled by varying the volumetric flow rates of the corresponding streams. We demonstrate one of the applications of the microfluidic method by co-encapsulating factor-dependent and responsive blood progenitor cell lines (MBA2 and M07e cells, respectively) at varying ratios, and show that in-bead paracrine secretion can modulate the viability of the factor dependent cells. Furthermore, we show the application of the method as a tool to screen the impact of specific growth factors on a primary human heterogeneous cell population. Co-encapsulation of IL-3 secreting MBA2 cells with umbilical cord blood cells revealed differential sub-population responsiveness to paracrine signals (CD14+ cells were particularly responsive to locally delivered IL-3). This microfluidic co-culture platform should enable high throughput screening of cell co-culture conditions, leading to new strategies to manipulate cell fate. PMID: 21526262 [PubMed - as supplied by publisher] | | | | | | | | | | | | | | | | | | | | | | | | | Bio-electrospraying primary cardiac cells: in vitro tissue creation and functional study. Biotechnol J. 2011 Jan;6(1):86-95 Authors: Ng KE, Joly P, Jayasinghe SN, Vernay B, Knight R, Barry SP, McComick J, Latchman D, Stephanou A Manifestations of myocardial infarctions have been recognized as one of the major killers in the Western world. Therefore, advancing and developing novel cardiac tissue repair and replacement therapeutics have great implications to our health sciences and well-being. There are several approaches for forming cardiac tissues, non-jet-based and jet-based methodologies. A unique advantage of jet-based approaches is the possibility to handle living cells with a matrix for cell distribution and deposition in suspension, either as single or heterogeneous cell populations. Our previous studies on bio-electrospraying of cardiac cells have shown great promise. Here, we show for the first time the ability to bio-electrospray the three major cell types of the myocardium, both independently and simultaneously, for forming a fully functional cardiac tissue. Several samples are characterized in vitro and found to be indistinguishable in comparison to controls. Thus, we are describing a swiftly emerging novel biotechnique for direct cardiac tissue generation. Moreover, the present investigations pave the way for the development and optimization of a bio-patterning approach for the fabrication of biologically viable cardiac tissue grafts for the potential treatment of severe heart failure after myocardial infarction. PMID: 21053334 [PubMed - indexed for MEDLINE] | | | | | | | | | | | | | | | | | | | | | | | | | Distinct stem cells subpopulations isolated from human adipose tissue exhibit different chondrogenic and osteogenic differentiation potential. Stem Cell Rev. 2011 Mar;7(1):64-76 Authors: Rada T, Reis RL, Gomes ME Recently adipose tissue has become a research topic also for the searching for an alternative stem cells source to use in cell based therapies such as tissue engineer. In fact Adipose Stem Cells (ASCs) exhibit an important differentiation potential for several cell lineages such as chondrogenic, osteogenic, myogenic, adipogenic and endothelial cells. ASCs populations isolated using standard methodologies (i.e., based on their adherence ability) are very heterogeneous but very few studies have analysed this aspect. Consequently, several questions are still pending, as for example, on what regard the existence/ or not of distinct ASCs subpopulations. The present study is originally aimed at isolating selected ASCs subpopulations, and to analyse their behaviour towards the heterogeneous population regarding the expression of stem cell markers and also regarding their osteogenic and chondrogenic differentiation potential. Human Adipose derived Stem Cells (hASCs) subpopulations were isolated using immunomagnetic beads coated with several different antibodies (CD29, CD44, CD49d, CD73, CD90, CD 105, Stro-1 and p75) and were characterized by Real Time RT-PCR in order to assess the expression of mesenchymal stem cells markers (CD44, CD73, Stro-1, CD105 and CD90) as well as known markers of the chondrogenic (Sox 9, Collagen II) and osteogenic lineage (Osteopontin, Osteocalcin). The obtained results underline the complexity of the ASCs population demonstrating that it is composed of several subpopulations, which express different levels of ASCs markers and exhibit distinctive differentiation potentials. Furthermore, the results obtained clearly evidence of the advantages of using selected populations in cell-based therapies, such as bone and cartilage regenerative medicine approaches. PMID: 20396979 [PubMed - indexed for MEDLINE] | | | | | | | | | | | | | | | | | | | | | | | | | Bladder substitute reconstructed in a physiological pressure environment. J Pediatr Urol. 2011 Apr 25; Authors: Bouhout S, Gauvin R, Gibot L, Aubé D, Bolduc S PURPOSE: Bladder reconstruction performed by enterocystoplasty or with bioengineered substitutes is still associated with complications, which led us to develop an autologous vesical equivalent (VE). This model has already proven its structural conformity. The challenge is to reconstruct our model in a more physiological environment, with the use of a bioreactor that mimics the dynamic of bladder filling and emptying, to acquire physiological properties. MATERIALS AND METHODS: Fibroblasts and urothelial cells evolved in a three-dimensional culture to obtain a reconstructed VE. This was then cultured in our bioreactor which delivers a cyclic pressure increase up to 15 cm H(2)O, followed by a rapid decrease, to achieve a dynamically cultured VE (dcVE). To compare with the statically cultured VE, the dcVE was characterized using histology and immunofluorescence. The mechanical resistance was evaluated by uniaxial tensile tests, and the permeability level was measured with 14C-urea. RESULTS: Compared to our static model, the dynamic culture led to a urothelium profile like that of native bladder. Permeability analysis displayed a profile comparable to native bladder, coinciding with basal cell organization in the dcVE, while an appropriate resistance for suturing and handling was shown. CONCLUSIONS: This new alternative method offers a promising avenue for regenerative medicine. It is distinguished by its autologous character and its efficiency as a barrier to urea. These properties could significantly reduce inflammation, necrosis, and therefore, possible rejection. PMID: 21527232 [PubMed - as supplied by publisher] | | | | | | | | | | | | | | | | | | | | | | | | | Coupling of gelatin to inner surfaces of pore walls in spongy alginate-based scaffolds facilitates the adhesion, growth and differentiation of human bone marrow mesenchymal stromal cells. J Mater Sci Mater Med. 2011 Apr 28; Authors: Petrenko YA, Ivanov RV, Petrenko AY, Lozinsky VI We have developed a novel wide-pore scaffold for cell 3D culturing, based on the technology of freeze-drying of Ca-alginate and gelatin. Two different preparation methodologies were compared: (i) freeze-drying of Na-alginate + gelatin mixed solution followed by the incubation of dried polymer in saturated ethanolic solution of CaCl(2); (ii) freeze-drying of the Na-alginate solution followed by the chemical "activation" of polysaccharide core with divinylsulfone with subsequent gelatin covalent attachment to the inner surfaces of pore walls. The scaffolds produced using the first approach did not provide adhesion and proliferation of human bone marrow mesenchymal stromal cells (MSCs). Conversely, the second approach allowed to obtain scaffolds with a high adherence ability for the cells. When cultured within the latter type of scaffold, MSCs proliferated and were able to differentiate into adipogenic, osteogenic and chondrogenic cell lineages, in response to specific induction stimuli. The results indicate that Ca-alginate wide-pore scaffolds with covalently attached gelatin could be useful for stem cell-based bone, cartilage and adipose tissue engineering. PMID: 21526407 [PubMed - as supplied by publisher] | | | | | | | | | | | | | | | | | | | | | | | | | Rosiglitazone-induced adipogenesis in a bone marrow mesenchymal stem cell line - biomed 2011. Biomed Sci Instrum. 2011;47:213-21 Authors: Wang D, Haile A, Jones LC In vitro modeling of adipose tissue is essential for the study of adipogenesis and related diseases as well as for the development of surgical reconstruction procedures and tissue-engineering applications. Peroxisome proliferator activated receptor ? (PPAR?) has been shown to play an integral role in stimulating adipogenesis. There are several established ligands for PPAR?, including rosiglitazone. D1 cells, a multipotential cell line derived from mouse bone marrow, were treated with increasing (0.1, 1, 10, and 30 µM) concentrations of rosiglitazone in DMEM for 48 hours followed by treatment by DMEM alone for up to 15 days. All doses of rosiglitazone stimulated the accumulation of lipids ,which was notable by day 6. The adipogenic effect of rosiglitazone was maximized at doses of 10 and 30 µM. Adipogenesis for rosiglitazone-treated cells was greater than that for cells treated with dexamethasone, a conventional method used to stimulate adipogenesis. Significantly higher levels of triglyceride-G (TG) and mature adipocyte markers (PPAR-, adipocyte fatty acid-binding protein) were observed with rosiglitazone treatment after 6 days. Cytokines in the supernatants were analyzed by multiplex-based ELISA assays at day 6 after treatment; these cells release adiponectin, resistin, PAI-1, MCP-1, and VEGF with either rosiglitazone or dexamethasone treatment. However, rosiglitazone treatment had lower osteocalcin release than did the control. This study provides evidence that rosiglitazone treatment is a reliable method that can be used to induce adipogenesis of D1 cells, a pluripotential cell line from mouse bone marrow. PMID: 21525623 [PubMed - in process] | | | | | | | | | | | | | | | | | | | | | | | | | Cellular and paracellular transplants for spinal cord injury: a review of the literature. Childs Nerv Syst. 2011 Feb;27(2):237-43 Authors: Mortazavi MM, Verma K, Tubbs RS, Theodore N Experimental approaches to limit the spinal cord injury and to promote neurite outgrowth and improved function from a spinal cord injury have exploded in recent decades. Due to the cavitation resulting after a spinal cord injury, newer important treatment strategies have consisted of implanting scaffolds with or without cellular transplants. There are various scaffolds, as well as various different cellular transplants including stem cells at different levels of differentiation, Schwann cells and peripheral nerve implants, that have been reviewed. Also, attention has been given to different re-implantation techniques in avulsion injuries. PMID: 20972681 [PubMed - indexed for MEDLINE] | | | | | | | | | | | | | | | | | | | | | | | | | Neuroblastoma and bone metastases: clinical significance and prognostic value of Dickkopf 1 plasma levels. Bone. 2011 Jan 1;48(1):152-9 Authors: Granchi D, Corrias MV, Garaventa A, Baglìo SR, Cangemi G, Carlini B, Paolucci P, Giunti A, Baldini N The critical role of the Wnt pathway inhibition in sustaining the onset of bone lesions has been demonstrated in a variety of bone diseases and tumors, and it has been associated with cancer aggressiveness. We have previously demonstrated that neuroblastoma cells express Dickkopf 1 (Dkk1), an inhibitor of the canonical Wnt pathway which prevents the differentiation of bone-forming cells. Since Dkk1 is a secreted factor, it could have potential clinical application as tumor marker for detecting bone metastasis and monitoring of disease. In this study, we investigated the diagnostic and prognostic value of Dkk1 plasma levels in 92 children affected by neuroblastoma, including 32 with bone metastases. Fifty-seven children hospitalized for minor surgical problems served as control group. Circulating levels of Dkk1 were higher in healthy children than in normal adults and were comparable to those found in adult patients with aggressive tumors. No significant differences were found between neuroblastoma patients and controls and between patients with and without bone metastases. However, when only patients with metastatic neuroblastoma were considered, the highest Dkk1 levels were detected in patients that poorly responded to induction chemotherapy and in subjects with unamplified MYCN and three or more different metastatic sites. The 'Receiver Operating Characteristic' curve enabled us to identify a threshold value to distinguish patients who were unresponsive to induction treatment. The relationship between Dkk1 and drug resistance was supported by in vitro experiments, since an increased sensitivity to doxorubicin was found in neuroblastoma cells releasing low Dkk1 levels, either constitutively or experimentally following the treatment with specific siRNA. In conclusion, Dkk1 is released by neuroblastoma cells and is able to affect the balance between osteoblastogenesis and osteoclastogenesis, thus favoring the onset of osteolytic metastases. Nevertheless, Dkk1 plasma levels do not allow the detection of bone lesions in neuroblastoma but seem to have a predictive value with regard to the severity and the prognosis of the disease in a subset of patients with metastatic tumor. New knowledge on the biological role of Dkk1 in driving the natural history of neuroblastoma has to be further investigated and could help to establish specific therapeutic strategies able to target key factors of tumor progression. PMID: 20603237 [PubMed - indexed for MEDLINE] | | | | | | | | | | | | | | | | | | | | | | | | | Cotransplantation of autologous bone marrow stromal cells and chondrocytes as a novel therapy for reconstruction of condylar cartilage. Med Hypotheses. 2011 Apr 25; Authors: Dai J, Wang X, Shen G Condylar cartilage is absolutely necessary for the normal function of temporomandibular joint (TMJ). Unfortunately, condylar cartilage defect or missing is also one of the common clinical problems. Repair or reconstruction of cartilage is always a hot topic. Cell based cartilage regeneration is suggested as novel therapies in cartilage tissue engineering, and autologous chondrocytes were initially regarded as the ideal cell source. However, there are some disadvantages such as its limited augmentation capability for culture in vitro and may differentiate to other types of cells. On the other hand, bone marrow stromal cells (BMSCs) have gained special interest in tissue engineering. Because they can be obtained easily, cause relatively minor trauma and show the potential of long-run ex vivo expansion capacity. What most important is their capacity of multi-directional differentiation. They can differentiate into a variety of other types of cells when there are supplement exogenous factors or genes, but their clinical use is limited by safety concerns such as toxicity, insertional teratogenic, uncontrollable gene expression. Fortunately, the chondrocytes microenvironment has been demonstrated that could induce BMSCs to structure cartilage when culture in vitro or reimplanted in nude mice subcutaneously area. So in this article, we hypothesize that cotransplantation of autologous BMSCs and chondrocytes, which coculture with extracellular scaffolds, is a novel therapy for reconstruction of TMJ condylar cartilage. In our strategy, advantages of two types of cells are utilized and shortcomings are avoided, which strongly improve the feasibility and clinical safety, finally bring great hope to the patients with TMJ disease. PMID: 21524860 [PubMed - as supplied by publisher] | | | | | | | | | | | | | | | | | | | | | | | | | Adult stem cells for cardiac tissue engineering. J Mol Cell Cardiol. 2011 Feb;50(2):312-9 Authors: Martinez EC, Kofidis T Cell therapy and tissue engineering attract increasing attention as a potential approach for cardiac repair. Adult stem cells from autologous origin are a practically safe and appealing source for cell-based regenerative therapies that may hold realistic clinical potential. A plethora of interesting concepts have been introduced aiming at regenerating ischemic myocardium through adult stem cell-based bioartificial cardiac tissue supplements. Yet, current pre-clinical concepts have not reached translational applicability, and successes are only episodic. This review will provide a brief overview of the latest concepts and breakthroughs in the emerging field of cardiac adult stem cell-based tissue engineering, and discuses the challenges that this field needs to overcome to achieve realistic therapeutic translation into the clinical arena. This article is part of a special issue entitled, "Cardiovascular Stem Cells Revisited". PMID: 20709074 [PubMed - indexed for MEDLINE] | | | | | | | | | | | | | | | | | | | | | | | | | [Preparation and properties of novel human-like collagen-silk fibroin scaffold for blood vessel]. Sheng Wu Gong Cheng Xue Bao. 2009 Aug;25(8):1225-33 Authors: Zhu C, Fan D, Ma X, Xue W, Hui J, Chen L, Duan Z, Ma P In order to improve tensile property of vascular scaffold, we blended silk fibroin with novel human-like collagen with the mass ratio of 9:1, 7:3 and 5:5 (W/W), and then fabricated blood vessel tubular graft by freeze-drying process. We studied microstructure, mechanical properties, elements composites, degradability and biocompatibility of vascular scaffolds. These results showed that tubular scaffold with mass ratio 7:3 exhibited interconnected porous structure with pore size at (60 +/- 5) microm and porosity of 85%; achieved the desirable mechanical property (strain of 50% +/- 5% and stress of 332 +/- 16 kPa); had relatively slow degradation rate; could enhance cell adhesion and proliferation and had superior biocompatibility. PMID: 19938461 [PubMed - indexed for MEDLINE] | | | | | | | | | | | | | | | | | | | | | | | | | Characterisation of chondrogenic differentiation of human mesenchymal stem cells using synchrotron FTIR microspectroscopy. Analyst. 2011 Apr 28; Authors: Chonanant C, Jearanaikoon N, Leelayuwat C, Limpaiboon T, Tobin MJ, Jearanaikoon P, Heraud P A major limiting factor in stem cell therapy is the accurate identification of the differentiation state of cells destined for transplantation. This study aimed to evaluate the potential of synchrotron radiation Fourier transform infrared (SR-FTIR) microspectroscopy as a novel technique to probe the differentiation state of human mesenchymal stem cells (hMSCs) to chondrocytes over a period of 7, 14 and 21 days of induction. The chondrogenic markers were determined using reverse transcription polymerase chain reaction, histology and immunohistochemistry. The changes of average spectra located near 1338-1230 and 1175-960 cm(-1) indicated increased levels of collagen and aggrecan, respectively, in chondrocyte-induced hMSCs compared with control cells. Classification of independent test spectra using partial least squares discriminant analysis (PLS-DA) could distinguish control and chondrocyte-induced cells with 100% accuracy. We conclude that the SR-FTIR microspectroscopy technique is sensitive for monitoring the differentiation state of stem cells under chondrogenic induction particularly at an early stage. It provides biochemical information that is complimentary to that obtained from conventional techniques, and may give more unambiguous results particularly at the very early stage of cellular differentiation. In addition, the spectroscopic approach is more straightforward, non-destructive and requires less sample preparation compared with the conventional methodologies. PMID: 21526247 [PubMed - as supplied by publisher] | | | | | | | | | | | | | | | | | | | | | | | | | Stem cells as a resource for regenerative neurology. Pract Neurol. 2011 Feb;11(1):29-36 Authors: Connick P, Patani R, Chandran S Public and media interest in the potential applications of stem cells in regenerative neurology has led to growing hope and expectation. This interest is heightened by the current paucity of treatments available for neurodegenerative diseases and their generally poor prognosis. Patient discussions about stem cells are therefore a common occurrence in clinical practice, requiring neurologists to offer clear and accurate information. In the context of a complex and rapidly evolving field, this can be extremely challenging. Here we address issues around stem cell populations relevant to regenerative neurology, including the opportunities they offer for research and their potential application as direct therapies, concluding with a pragmatic assessment of the likely clinical benefits of stem cell research. PMID: 21239652 [PubMed - indexed for MEDLINE] | | | | | | | | | | | | | | | | | | | | | | | | | Bottom-up tissue engineering. Curr Opin Biotechnol. 2011 Apr 25; Authors: Elbert DL Recapitulating the elegant structures formed during development is an extreme synthetic and biological challenge. Great progress has been made in developing materials to support transplanted cells, yet the complexity of tissues is far beyond that found in even the most advanced scaffolds. Self-assembly is a motif used in development and a route for the production of complex materials. Self-assembly of peptides, proteins and other molecules at the nanoscale is promising, but in addition, intriguing ideas are emerging for self-assembly of micron-scale structures. In this brief review, very recent advances in the assembly of micron-scale cell aggregates and microgels will be described and discussed. PMID: 21524904 [PubMed - as supplied by publisher] | | | | | | | | | | | | | | | | | | | | | | | | | Hemodynamic Activation of {beta}-Catenin and TCF Signaling in Vascular Endothelium Regulates Fibronectin Expression. Arterioscler Thromb Vasc Biol. 2011 Apr 28; Authors: Gelfand BD, Meller J, Pryor AW, Kahn M, Bortz PD, Wamhoff BR, Blackman BR OBJECTIVE: The goal of this study was to assess the activity of β-catenin/TCF signaling in atherosclerosis development and its regulation of fibronectin in vascular endothelium. METHODS AND RESULTS: Histological staining identified preferential nuclear localization of β-catenin in the endothelium of atheroprone aorta before and during lesion development. Transgenic reporter studies revealed that increased levels of TCF transcriptional activity in endothelium correlated anatomically with β-catenin nuclear localization and fibronectin deposition. Exposure of endothelial cells to human-derived atheroprone shear stress induced nuclear localization of β-catenin, transcriptional activation of TCF, and expression of fibronectin. Activation of fibronectin expression required β-catenin, TCF, and the transcriptional coactivator CBP. Finally, we identified PECAM-1 as a critical regulator of constitutive β-catenin and glycogen synthase kinase-3β activities. CONCLUSIONS: These data reveal novel constitutive activation of the endothelial β-catenin/TCF signaling pathway in atherosclerosis and regulation of fibronectin through hemodynamic shear stress. PMID: 21527747 [PubMed - as supplied by publisher] | | | | | | | | | | | | | | | | | | | | | | | | | [Patterning different cells based on microfluidics and self-assembled monolayers]. Sheng Wu Gong Cheng Xue Bao. 2009 Aug;25(8):1234-9 Authors: Wu J, Shao J, Zheng Y, Jin Q, Zhao J The ability to pattern multiple cells through precise surface engineering of cell culture substrates has promoted the development of cellular bioassays, such as differentiation, interaction and molecular signaling pathways. There are several well developed ways to pattern cells. This report describes a method for patterning multiple types of cells based on microfluidics and self-assembled monolayers. We developed two types of micro-dam structures by soft-lithography to locate cells precisely and modified the substrate by a kind of self-assembled monolayer with property of electrochemical desorption to confine cells in specific areas. Finally we could pattern an array of two different types of cells closely and precisely. Cells were confined in specific areas but still shared the same microenvironment, so they could interact through soluble molecules. The substrate was transparent and open, so we could easily apply several instruments for research. With these merits, this cell chip is appropriate for investigating the interaction between different types of cells. PMID: 19938462 [PubMed - indexed for MEDLINE] | | | | | | | | | | | | | | | | | | | | | | | | | Keeping things simple. Nat Methods. 2011 May;8(5):389-90 Authors: Rao M PMID: 21527929 [PubMed - in process] | | | | | | | | | | | | | | | | | | | | | | | | | Controlled activation of morphogenesis to generate a functional human microvasculature in a synthetic matrix. Blood. 2011 Apr 28; Authors: Hanjaya-Putra D, Bose V, Shen YI, Yee J, Khetan S, Fox-Talbot K, Steenbergen C, Burdick JA, Gerecht S Understanding the role of the extracellular matrix (ECM) in vascular morphogenesis has been possible using natural ECMs as in vitro models to study the underlying molecular mechanisms. However, little is known about vascular morphogenesis in synthetic matrices where properties can be tuned, towards both the basic understanding of tubulogenesis in modular environments and as a clinically relevant alternative to natural materials for regenerative medicine. We investigated synthetic, tunable hyaluronic acid (HA) hydrogels and determined both the adhesion and degradation parameters that enable human endothelial colony-forming cells (ECFCs) to form efficient vascular networks. Entrapped ECFCs underwent tubulogenesis dependent on the cellular interactions with the HA hydrogel during each stage of vascular morphogenesis. Vacuole and lumen formed through integrins α(5)β(1) and α(V)β(3), while branching and sprouting were enabled by HA hydrogel degradation. Vascular networks formed within HA hydrogels containing ECFCs anastomosed with the host's circulation and supported blood flow in the hydrogel following transplantation. Collectively we show that the signaling pathways of vascular morphogenesis of ECFCs can be precisely regulated in a synthetic matrix, resulting in a functional microvasculature useful for the study of three-dimensional vascular biology and towards a range of vascular disorders and approaches in tissue regeneration. PMID: 21527523 [PubMed - as supplied by publisher] | | | | | | | | | | | | | | | | | | | | | | | | | Plasticity of human menstrual blood stem cells derived from the endometrium. J Zhejiang Univ Sci B. 2011 May;12(5):372-380 Authors: Lin J, Xiang D, Zhang JL, Allickson J, Xiang C Stem cells can be obtained from women's menstrual blood derived from the endometrium. The cells display stem cell markers such as Oct-4, SSEA-4, Nanog, and c-kit (CD117), and have the potent ability to differentiate into various cell types, including the heart, nerve, bone, cartilage, and fat. There has been no evidence of teratoma, ectopic formation, or any immune response after transplantation into an animal model. These cells quickly regenerate after menstruation and secrete many growth factors to display recurrent angiogenesis. The plasticity and safety of the acquired cells have been demonstrated in many studies. Menstrual blood-derived stem cells (MenSCs) provide an alternative source of adult stem cells for research and application in regenerative medicine. Here we summarize the multipotent properties and the plasticities of MenSCs and other endometrial stem cells from recent studies conducted both in vitro and in vivo. PMID: 21528491 [PubMed - as supplied by publisher] | | | | | | | | | | | | | | | | | | | | | | | | | Inhibition of cellular senescence by developmentally regulated FGF-receptors in mesenchymal stem cells. Blood. 2011 Apr 28; Authors: Coutu DL, François M, Galipeau J Bone-derived mesenchymal stem cells (MSCs) are important cells for use in cell therapy, tissue engineering and regenerative medicine but also to study bone development, homeostasis and repair. However, little is known about their developmental ontology and in vivo identity. Because FGFs play key roles in bone development and their receptors are developmentally regulated in bones, we here hypothesized that MSCs should express FGF-receptors reflecting their developmental origin and potential. We show that FGFR1 and 2 are expressed by rare mesenchymal progenitors in putative MSC niches in vivo including perichondrium, periosteum and trabecular marrow. FGFR1+ cells often appeared as pericytes. These cells display a characteristic MSC phenotype in vitro when expanded with FGF-2, which appears to maintain MSC stemness by inhibiting cellular senescence through a PI3K/AKT-MDM2 pathway and promoting proliferation. FGFRs may thus be involved in MSCs self-renewal. In summary, FGFR1/2 are developmentally-regulated markers of MSCs in vivo and in vitro and are important to maintain MSCs stemness. PMID: 21527526 [PubMed - as supplied by publisher] | | | | | | | | | | | | | | | | | | | | | | | | | A sandwich model for engineering cartilage with acellular cartilage sheets and chondrocytes. Biomaterials. 2011 Mar;32(9):2265-73 Authors: Gong YY, Xue JX, Zhang WJ, Zhou GD, Liu W, Cao Y Acellular cartilage can provide a native extracellular matrix for cartilage engineering. However, it is difficult for cells to migrate into acellular cartilage because of its non-porous structure. The aim of this study is to establish a sandwich model for engineering cartilage with acellular cartilage sheets and chondrocytes. Cartilage from adult pig ear was cut into a circular cylinder with a diameter of approximately 6 mm and freeze-sectioned at thicknesses of 10 μm and 30 μm. The sheets were then decellularized and lyophilized. Chondrocytes isolated from newborn pig ear were expanded for 2 passages. The acellular sheets and chondrocytes were then stacked layer-by-layer, in a sandwich model, and cultured in dishes. After 4 weeks of cultivation, the constructs were then either maintained in culture for another 12 weeks or implanted subcutaneously in nude mouse. Histological analysis showed that cells were completely removed from cartilage sheets after decellularization. By re-seeding cells and stacking 20 layers of sheets together, a cylinder-shaped cell sheet was achieved. Cartilage-like tissues formed after 4 weeks of culture. Histological analyses showed the formation of cartilage with a typical lacunar structure. Cartilage formation was more efficient with 10 μm-thick sheets than with 30 μm sheets. Mature cartilage was achieved after 12 weeks of implantation, which was demonstrated by histology and confirmed by Safranin O, Toluidine blue and anti-type II collagen antibody staining. Furthermore, we achieved cartilage with a designed shape by pre-shaping the sheets prior to implantation. These results indicate that the sandwich model could be a useful model for engineering cartilage in vitro and in vivo. PMID: 21194746 [PubMed - indexed for MEDLINE] | | | | | | | | | | | | | | | | | | | | | | | | | Regenerative endodontics: A state of the art. Indian J Dent Res. 2011 Jan-Feb;22(1):122-31 Authors: Bansal R, Bansal R Scientific advances in the creation of restorative biomaterials, in vitro cell culture technology, tissue grafting, tissue engineering, molecular biology and the human genome project provide the basis for the introduction of new technologies into dentistry. Non-vital infected teeth have long been treated with root canal therapy (for mature root apex) and apexification (for immature root apex), or doomed to extraction. Although successful, current treatments fail to re-establish healthy pulp tissue in these teeth. But, what if the non-vital tooth could be made vital once again? That is the hope offered by regenerative endodontics, an emerging field focused on replacing traumatized and diseased pulp with functional pulp tissue. Restoration of vitality of non-vital tooth is based on tissue engineering and revascularization procedures. The purpose of this article is to review these biological procedures and the hurdles that must be overcome to develop regenerative endodontic procedures. PMID: 21525690 [PubMed - in process] | | | | | | | | | | | | | | | | | | | | | | | | | Embryonic and embryonic-like stem cells in heart muscle engineering. J Mol Cell Cardiol. 2011 Feb;50(2):320-6 Authors: Zimmermann WH Cardiac muscle engineering is evolving rapidly and may ultimately be exploited to (1) model cardiac development, physiology, and pathology; (2) identify and validate drug targets; (3) assess drug safety and efficacy; and (4) provide therapeutic substitute myocardium. The ultimate success in any of these envisioned applications depends on the utility of human cells and their assembly into myocardial equivalents with structural and functional properties of mature heart muscle. Embryonic stem cells appear as a promising cell source in this respect, because they can be cultured reliably and differentiated robustly into cardiomyocytes. Despite their unambiguous cardiogenicity, data on advanced maturation and seamless myocardial integration of embryonic stem cell-derived cardiomyocytes in vivo are sparse. Additional concerns relate to the limited control over cardiomyogenic specification and cardiomyocyte maturation in vitro as well as the risk of teratocarcinoma formation and immune rejection of stem cell implants in vivo. Through the invent of embryonic-like stem cells - such as parthenogenetic stem cells, male germline stem cells, and induced pluripotent stem cells - some but certainly not all of these issues may be addressed, albeit at the expense of additional concerns. This review will discuss the applicability of embryonic and embryonic-like stem cells in myocardial tissue engineering and address issues that require particular attention before the potential of stem cell-based heart muscle engineering may be fully exploited. This article is part of a special issue entitled, "Cardiovascular Stem Cells Revisited". PMID: 21040727 [PubMed - indexed for MEDLINE] | | | | | | | | | | | | | | | | | | | | | | | | | Laser-assisted bioprinting for creating on-demand patterns of human osteoprogenitor cells and nano-hydroxyapatite. Biofabrication. 2011 Apr 28;3(2):025001 Authors: Catros S, Fricain JC, Guillotin B, Pippenger B, Bareille R, Remy M, Lebraud E, Desbat B, Amédée J, Guillemot F Developing tools to reproduce and manipulate the cell micro-environment, including the location and shape of cell patterns, is essential for tissue engineering. Parallel to inkjet printing and pressure-operated mechanical extruders, laser-assisted bioprinting (LAB) has emerged as an alternative technology to fabricate two- and three-dimensional tissue engineering products. The objective of this work was to determine laser printing parameters for patterning and assembling nano-hydroxyapatite (nHA) and human osteoprogenitors (HOPs) in two and three dimensions with LAB. The LAB workstation used in this study comprised an infrared laser focused on a quartz ribbon that was coated with a thin absorbing layer of titanium and a layer of bioink. The scanning system, quartz ribbon and substrate were piloted by dedicated software, allowing the sequential printing of different biological materials into two and/or three dimensions. nHA printing material (bioink) was synthesized by chemical precipitation and was characterized prior and following printing using transmission electron microscopy, Fourier transformed infrared spectroscopy and x-ray diffraction. HOP bioink was prepared using a 30 million cells ml(-1) suspension in culture medium and cells were characterized after printing using a Live/Dead assay and osteoblastic phenotype markers (alcaline phosphatase and osteocalcin). The results revealed that LAB allows printing and organizing nHA and HOPs in two and three dimensions. LAB did not alter the physico-chemical properties of nHA, nor the viability, proliferation and phenotype of HOPs over time (up to 15 days). This study has demonstrated that LAB is a relevant method for patterning nHA and osteoblastic cells in 2D, and is also adapted to the bio-fabrication of 3D composite materials. PMID: 21527813 [PubMed - as supplied by publisher] | | | | | | | | | | | | | | | | | | | | | | | | | Therapeutic potentials of mesenchymal stem cells derived from human umbilical cord. Stem Cell Rev. 2011 Mar;7(1):195-207 Authors: Fan CG, Zhang QJ, Zhou JR Human umbilical cord-derived mesenchymal stem cells (hUC-MSCs), isolated from discarded extra-embryonic tissue after birth, are promising candidate source of mesenchymal stem cells (MSCs). Apart from their prominent advantages in abundant supply, painless collection, and faster self-renewal, hUC-MSCs have shown the potencies to differentiate into a variety of cells of three germ layers (such as bone, cartilage, adipose, skeletal muscle, cardiomyocyte, endothelium, hepatocyte-like cluster, islet-like cluster, neuron, astrocyte and oligodendrocyte), to synthesize and secret a set of trophic factors and cytokines, to support the expansion and function of other cells (like hematopoietic stem cells, embryonic stem cells, natural killer cells, islet-like cell clusters, neurons and glial cells), to migrate toward and home to pathological areas, and to be readily transfected with conventional methods. Two excellent previous reviews documenting the characteristics of this cell population with special emphasis on its niche, isolation, surface markers and primitive properties have been published recently. In this review, we will firstly give a brief introduction of this cell population, and subsequently dwell on the findings of differential capacities with emphasis on its therapeutic potentials. PMID: 20676943 [PubMed - indexed for MEDLINE] | | | | | | | | | | | | | | | | | | | | | | | | | Derivation of human induced pluripotent stem cells for cardiovascular disease modeling. Circ Res. 2011 Apr 29;108(9):1146-56 Authors: Narsinh K, Narsinh KH, Wu JC The successful derivation of human induced pluripotent stem cells (hiPSCs) by dedifferentiation of somatic cells offers significant potential to overcome obstacles in the field of cardiovascular disease. hiPSC derivatives offer incredible potential for new disease models and regenerative medicine therapies. However, many questions remain regarding the optimal starting materials and methods to enable safe, efficient derivation of hiPSCs suitable for clinical applications. Initial reprogramming experiments were carried out using lentiviral or retroviral gene delivery methods. More recently, various nonviral methods that avoid permanent and random transgene insertion have emerged as alternatives. These include transient DNA transfection using plasmids or minicircles, protein transduction, or RNA transfection. In addition, several small molecules have been found to significantly augment hiPSC derivation efficiency, allowing the use of a fewer number of genes during pluripotency induction. We review these various methods for the derivation of hiPSCs, focusing on their ultimate clinical applicability, with an emphasis on their potential for use as cardiovascular therapies and disease-modeling platforms. PMID: 21527744 [PubMed - in process] | | | | | | | | | | | | | | | | | | | | | | | | | Stem cell therapy: A challenge to periodontist. Indian J Dent Res. 2011 Jan-Feb;22(1):132-9 Authors: Mudda JA, Bajaj M Periodontitis is an inflammatory disease which manifests clinically as loss of supporting periodontal tissues including periodontal ligament, cementum, and alveolar bone, and periodontal therapy is aimed at achieving complete regeneration of these structures. To date, this goal has been tried to accomplish using various bone grafts, growth factors, and barrier membranes. Stem cells are the most fascinating area of biology today and have been used clinically in the field of medicine to treat many incurable diseases. Various human and animal studies have confirmed the presence of stem cells in dental tissues including periodontal ligament. This has opened new avenues aiming toward complete periodontal regeneration using cell-based therapies. This review provides an overview of various types of stem cells in medicine and dentistry and their potential uses especially pertaining to periodontal regeneration. PMID: 21525691 [PubMed - in process] | | | | | | | | | | | | | | | | | | | | | | | | | Preparation of decellularized and crosslinked artery patch for vascular tissue-engineering application. J Mater Sci Mater Med. 2011 Apr 28; Authors: Zhao Y, Zhang Z, Wang J, Yin P, Wang Y, Yin Z, Zhou J, Xu G, Liu Y, Deng Z, Zhen M, Cui W, Liu Z There is an urgent clinical need of tissue-engineering (TE) vascular grafts, so this study was for developing a fast and simple way of producing TE vascular scaffold. The TE vascular scaffold was prepared with pepsin, DNase and RNase enzymatic decellularization and crosslinked with 0.1, 1, 5% glutaraldehyde (GA), respectively. The samples were underwent analyses of burst pressure; suture strength; cytotoxicity; enzymatic degradation in vitro; degradation in vivo; rehydration; biocompatibilities detected with hematoxylin and eosin (H&E), scan electron microscope, immunohistochemistry both in vivo and in vitro; macrophage infiltration and calcification using Von Kossa staining. After being decellularized the scaffold had a complete removal of cellular components, an intact collagen structure. The burst pressure and suture strength were similar to native artery. 0.1% GA crosslinked scaffold showed less cytotoxicity than 1 and 5% GA groups (P < 0.05) and was resistance to enzymatic degradation in vitro. Once being implanted, 0.1% GA group was resistant to degradation and formed endothelium, smooth muscle and adventitia with few macrophages infiltration. However, there appeared calcification in implants compared with that in native artery. This study demonstrated that DVPs producing methods by enzymatic decellularizing and crosslinking with 0.1% GA could be used for clinical TE vascular graft manufacture. PMID: 21528356 [PubMed - as supplied by publisher] | | | | | | | | | | | | | | | | | | | | | | | | | Solid-state cryomilling for porogen mixing and porous scaffold fabrication - biomed 2011. Biomed Sci Instrum. 2011;47:258-63 Authors: Allaf RM, Rivero IV Several widely used techniques for the fabrication of three dimensional (3D) scaffolds utilize the particulate leaching method to achieve a porous structure. This method involves the selective leaching of a mineral or an organic compound to generate pores. However, scaffolds prepared by this technique tend to exhibit limited interconnectivity. Therefore, to enhance the interconnectivity of the scaffolds fabricated by particulate leaching, a polymeric porogen can be added during processing. Typically porogens are mixed into a polymer solution, powder, or melt. The mixture is subsequently cast, molded, or extruded, and then leaching the porogens results in porous scaffolds. Still, even though scaffold interconnectivity is improved through the addition of polymer porogens, particulate leaching does not yield scaffolds with uniform properties. This research introduces a new solventless approach, cryomilling, to blend porogens and attain interconnected porous scaffolds with uniform morphologies. To validate the efficacy of the suggested approach a comparison of the effect of various solid-state mixing approaches on scaffold morphology and mechanical properties will be made. In this study, salt particles and poly(ethylene oxide) (PEO) were mixed (manually or through cryomilling) with poly(e-caprolactone) (PCL) for the preparation of porous 3D PCL scaffolds, the mixtures were then compression molded, and subsequently, water was used to leach the porogens. Morphological and compressive properties of the resulting scaffolds will be discussed. This simple, novel, economical, organic solvent-free approach for the fabrication of 3D interconnected porous scaffolds holds promise for tissue engineering applications. PMID: 21525630 [PubMed - in process] | | | | | | | | | | | | | | | | | | | | | | | | | Fabrication of nano-structured electrospun collagen scaffold intended for nerve tissue engineering. J Mater Sci Mater Med. 2011 Apr 28; Authors: Timnak A, Yousefi Gharebaghi F, Pajoum Shariati R, Bahrami SH, Javadian S, Hojjati Emami S, Shokrgozar MA Nerve tissue engineering is one of the most promising methods in nerve tissue regeneration. The development of blended collagen and glycosaminoglycan scaffolds can potentially be used in many soft tissue engineering applications. In this study an attempt was made to develop two types of random and aligned electrospun, nanofibrous scaffold using collagen and a common type of glycosaminoglycan. Ion chromatography test, MTT and attachment assays were conducted respectively to trace the release of glycosaminoglycan, and to investigate the biocompatibility of the scaffold. Cell cultural tests showed that the scaffold acted as a positive factor to support connective tissue cell outgrowth. The positive effect of fiber orientation on cell outgrowth organization was traced through SEM images. Porosity percentage calculation and tensile strength measurement of the webs specified analogous properties to the native neural matrix tissue. These results suggested that nanostructured porous collagen-glycosaminoglycan scaffold is a potential cell carrier in nerve tissue engineering. PMID: 21526410 [PubMed - as supplied by publisher] | | | | | | | | | | | | | | | | | | | | | | | | | Fully biodegradable self-rolled polymer tubes: a candidate for tissue engineering scaffolds. Biomacromolecules. 2011 Apr 27; Authors: Zakharchenko S, Sperling E, Ionov L We report an approach for the fabrication of fully biodegradable self-rolled tubes based on patterned polysuccinimide/polycaprolactone bilayers. These polymers are biocompatible, biodegradable, produced industrially and are already approved for biomedical purposes. Both polycaprolactone and polysuccinimide are hydrophobic and intrinsically water insoluble. Polysuccinimide, however, is able to hydrolyze in physiological buffer environment yielding water-swellable polyaspartic acid that causes rolling of polymer bilayer and formation of tubes. We demonstrate the possibility to encapsulate yeast cells using self-rolled tubes. PMID: 21524116 [PubMed - as supplied by publisher] | | | | | | | | | | | | | | | | | | | | | | | | | Designs from the deep: Marine organisms for bone tissue engineering. Biotechnol Adv. 2011 Apr 17; Authors: Clarke SA, Walsh P, Maggs CA, Buchanan F Current strategies for bone repair have accepted limitations and the search for synthetic graft materials or for scaffolds that will support ex vivo bone tissue engineering continues. Biomimetic strategies have led to the investigation of naturally occurring porous structures as templates for bone growth. The marine environment is rich in mineralizing organisms with porous structures, some of which are currently being used as bone graft materials and others that are in early stages of development. This review describes the current evidence available for these organisms, considers the relative promise of each and suggests potential future directions. PMID: 21527337 [PubMed - as supplied by publisher] | | | | | | | | | | | | | | | | | | | | | | | | | Human bone marrow mesenchymal stem cells: a systematic reappraisal via the genostem experience. Stem Cell Rev. 2011 Mar;7(1):32-42 Authors: Charbord P, Livne E, Gross G, Häupl T, Neves NM, Marie P, Bianco P, Jorgensen C Genostem (acronym for "Adult mesenchymal stem cells engineering for connective tissue disorders. From the bench to the bed side") has been an European consortium of 30 teams working together on human bone marrow Mesenchymal Stem Cell (MSC) biological properties and repair capacity. Part of Genostem activity has been dedicated to the study of basic issues on undifferentiated MSCs properties and on signalling pathways leading to the differentiation into 3 of the connective tissue lineages, osteoblastic, chondrocytic and tenocytic. We have evidenced that native bone marrow MSCs and stromal cells, forming the niche of hematopoietic stem cells, were the same cellular entity located abluminally from marrow sinus endothelial cells. We have also shown that culture-amplified, clonogenic and highly-proliferative MSCs were bona fide stem cells, sharing with other stem cell types the major attributes of self-renewal and of multipotential priming to the lineages to which they can differentiate (osteoblasts, chondrocytes, adipocytes and vascular smooth muscle cells/pericytes). Extensive transcription profiling and in vitro and in vivo assays were applied to identify genes involved in differentiation. Thus we have described novel factors implicated in osteogenesis (FHL2, ITGA5, Fgf18), chondrogenesis (FOXO1A) and tenogenesis (Smad8). Another part of Genostem activity has been devoted to studies of the repair capacity of MSCs in animal models, a prerequisite for future clinical trials. We have developed novel scaffolds (chitosan, pharmacologically active microcarriers) useful for the repair of both bone and cartilage. Finally and most importantly, we have shown that locally implanted MSCs effectively repair bone, cartilage and tendon. PMID: 20198518 [PubMed - indexed for MEDLINE] | | | | | | | | | | | | | | | | | | | | | | | | | Versican targeting by RNA interference suppresses aggregative growth of dermal papilla cells. Clin Exp Dermatol. 2011 Jan;36(1):77-84 Authors: Feng M, Yang G, Wu J Dermal papilla cells (DPCs) are specialized fibroblasts found in the hair follicle papilla, which are associated with the development and cycle regulation of hair follicles (HFs). DPCs exhibit a multilayer aggregative growth character, which is closely related to induction of HF formation. Versican, a large chondroitin sulphate proteoglycan and one of the major components of the extracellular matrix, is involved in the formation of HF. PMID: 20804505 [PubMed - indexed for MEDLINE] | | | | | | | | | | | | | | | | | | | | | | | | | OLIG gene targeting in human pluripotent stem cells for motor neuron and oligodendrocyte differentiation. Nat Protoc. 2011 Apr;6(5):640-55 Authors: Liu Y, Jiang P, Deng W Pluripotent stem cells can be genetically labeled to facilitate differentiation studies. In this paper, we describe a gene-targeting protocol to knock in a GFP cassette into key gene loci in human pluripotent stem cells (hPSCs), and then use the genetically tagged hPSCs to guide in vitro differentiation, immunocytochemical and electrophysiological profiling and in vivo characterization after cell transplantation. The Olig transcription factors have key roles in the transcription regulatory pathways for the genesis of motor neurons (MNs) and oligodendrocytes (OLs). We have generated OLIG2-GFP hPSC reporter lines that reliably mark MNs and OLs for monitoring their sequential differentiation from hPSCs. The expression of the GFP reporter recapitulates the endogenous expression of OLIG genes. The in vitro characterization of fluorescence-activated cell sorting-purified cells is consistent with cells of the MN or OL lineages, depending on the stages at which they are collected. This protocol is efficient and reliable and usually takes 5-7 months to complete. The genetic tagging-differentiation methodology used herein provides a general framework for similar work for differentiation of hPSCs into other lineages. PMID: 21527921 [PubMed - in process] | | | | | | | | | |  | |  | |  |
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