Publications by authors named "Catarina Miranda"

13 Publications

  • Page 1 of 1

Bioactivity of Chitosan-Based Particles Loaded with Plant-Derived Extracts for Biomedical Applications: Emphasis on Antimicrobial Fiber-Based Systems.

Mar Drugs 2021 Jun 23;19(7). Epub 2021 Jun 23.

Centre for Textile Science and Technology (2C2T), University of Minho, Campus de Azurém, 4800-058 Guimarães, Portugal.

Marine-derived chitosan (CS) is a cationic polysaccharide widely studied for its bioactivity, which is mostly attached to its primary amine groups. CS is able to neutralize reactive oxygen species (ROS) from the microenvironments in which it is integrated, consequently reducing cell-induced oxidative stress. It also acts as a bacterial peripheral layer hindering nutrient intake and interacting with negatively charged outer cellular components, which lead to an increase in the cell permeability or to its lysis. Its biocompatibility, biodegradability, ease of processability (particularly in mild conditions), and chemical versatility has fueled CS study as a valuable matrix component of bioactive small-scaled organic drug-delivery systems, with current research also showcasing CS's potential within tridimensional sponges, hydrogels and sutures, blended films, nanofiber sheets and fabric coatings. On the other hand, renewable plant-derived extracts are here emphasized, given their potential as eco-friendly radical scavengers, microbicidal agents, or alternatives to antibiotics, considering that most of the latter have induced bacterial resistance because of excessive and/or inappropriate use. Loading them into small-scaled particles potentiates a strong and sustained bioactivity, and a controlled release, using lower doses of bioactive compounds. A pH-triggered release, dependent on CS's protonation/deprotonation of its amine groups, has been the most explored stimulus for that control. However, the use of CS derivatives, crosslinking agents, and/or additional stabilization processes is enabling slower release rates, following extract diffusion from the particle matrix, which can find major applicability in fiber-based systems within ROS-enriched microenvironments and/or spiked with microbes. Research on this is still in its infancy. Yet, the few published studies have already revealed that the composition, along with an adequate drug release rate, has an important role in controlling an existing infection, forming new tissue, and successfully closing a wound. A bioactive finishing of textiles has also been promoting high particle infiltration, superior washing durability, and biological response.
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http://dx.doi.org/10.3390/md19070359DOI Listing
June 2021

Functionalization of Crosslinked Sodium Alginate/Gelatin Wet-Spun Porous Fibers with Nisin Z for the Inhibition of -Induced Infections.

Int J Mol Sci 2021 Feb 16;22(4). Epub 2021 Feb 16.

Centre for Textile Science and Technology (2C2T), Department of Textile Engineering, University of Minho, Campus of Azurém, 4800-058 Guimarães, Portugal.

Nisin Z, an amphipathic peptide, with a significant antibacterial activity against Gram-positive bacteria and low toxicity in humans, has been studied for food preservation applications. Thus far, very little research has been done to explore its potential in biomedicine. Here, we report the modification of sodium alginate (SA) and gelatin (GN) blended microfibers, produced via the wet-spinning technique, with Nisin Z, with the purpose of eradicating -induced infections. Wet-spun SAGN microfibers were successfully produced at a 70/30% / of SA (2 wt%)/GN (1 wt%) polymer ratio by extrusion within a calcium chloride (CaCl) coagulation bath. Modifications to the biodegradable fibers' chemical stability and structure were then introduced via crosslinking with CaCl and glutaraldehyde (SAGNCL). Regardless of the chemical modification employed, all microfibers were labelled as homogeneous both in size (≈246.79 µm) and shape (cylindrical and defect-free). SA-free microfibers, with an increased surface area for peptide immobilization, originated from the action of phosphate buffer saline solution on SAGN fibers, were also produced (GNCL). Their durability in physiological conditions (simulated body fluid) was, however, compromised very early in the experiment (day 1 and 3, with and without Nisin Z, respectively). Only the crosslinked SAGNCL fibers remained intact for the 28 day-testing period. Their thermal resilience in comparison with the unmodified and SA-free fibers was also demonstrated. Nisin Z was functionalized onto the unmodified and chemically altered fibers at an average concentration of 178 µg/mL. Nisin Z did not impact on the fiber's morphology nor on their chemical/thermal stability. However, the peptide improved the SA fibers (control) structural integrity, guaranteeing its stability for longer, in physiological conditions. Its main effect was detected on the time-kill kinetics of the bacteria . SAGNCL and GNCL loaded with Nisin Z were capable of progressively eliminating the bacteria, reaching an inhibition superior to 99% after 24 h of culture. The peptide-modified SA and SAGN were not as effective, losing their antimicrobial action after 6 h of incubation. Bacteria elimination was consistent with the release kinetics of Nisin Z from the fibers. In general, data revealed the increased potential and durable effect of Nisin Z (significantly superior to its free, unloaded form) against -induced infections, while loaded onto prospective biomedical wet-spun scaffolds.
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http://dx.doi.org/10.3390/ijms22041930DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7919837PMC
February 2021

Mesenchymal stromal cells to fight SARS-CoV-2: Taking advantage of a pleiotropic therapy.

Cytokine Growth Factor Rev 2021 04 15;58:114-133. Epub 2020 Dec 15.

CNC - Center for Neuroscience and Cell Biology, University of Coimbra, Portugal; CIBB- Center for Innovative Biomedicine and Biotechnology, University of Coimbra, 3004-504 Coimbra, Portugal; III - Institute for Interdisciplinary Research, University of Coimbra, 3030-789 Coimbra, Portugal. Electronic address:

The devastating global impact of the Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) has prompted scientists to develop novel strategies to fight Coronavirus Disease of 2019 (COVID-19), including the examination of pre-existing treatments for other viral infections in COVID-19 patients. This review provides a reasoned discussion of the possible use of Mesenchymal Stromal Cells (MSC) or their products as a treatment in SARS-CoV-2-infected patients. The main benefits and concerns of using this cellular therapy, guided by preclinical and clinical data obtained from similar pathologies will be reviewed. MSC represent a highly immunomodulatory cell population and their use may be safe according to clinical studies developed in other pathologies. Notably, four clinical trials and four case reports that have already been performed in COVID-19 patients obtained promising results. The clinical application of MSC in COVID-19 is very preliminary and further investigational studies are required to determine the efficacy of the MSC therapy. Nevertheless, these preliminary studies were important to understand the therapeutic potential of MSC in COVID-19. Based on these encouraging results, the United States Food and Drug Administration (FDA) authorized the compassionate use of MSC, but only in patients with Acute Respiratory Distress Syndrome (ARDS) and a poor prognosis. In fact, patients with severe SARS-CoV-2 can present infection and tissue damage in different organs, such as lung, heart, liver, kidney, gut and brain, affecting their function. MSC may have pleiotropic activities in COVID-19, with the capacity to fight inflammation and repair lesions in several organs.
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http://dx.doi.org/10.1016/j.cytogfr.2020.12.002DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7836230PMC
April 2021

Single Cell Oil Production by Oleaginous Yeasts Grown in Synthetic and Waste-Derived Volatile Fatty Acids.

Microorganisms 2020 Nov 17;8(11). Epub 2020 Nov 17.

CBMA-Centre of Molecular and Environmental Biology, Department of Biology, University of Minho, Campus de Gualtar, 4710-057 Braga, Portugal.

Four yeast isolates from the species-, , , and -previously selected by their oleaginous character and growth flexibility in different carbon sources, were tested for their capacity to convert volatile fatty acids into lipids, in the form of single cell oils. Growth, lipid yields, volatile fatty acids consumption, and long-chain fatty acid profiles were evaluated in media supplemented with seven different volatile fatty acids (acetic, butyric, propionic, isobutyric, valeric, isovaleric, and caproic), and also in a dark fermentation effluent filtrate. Yeasts and attained lipid productivities of more than 40% (/), mainly composed of oleic (>40%), palmitic (20%), and stearic (20%) acids, both in synthetic media and in the waste-derived effluent filtrate. These isolates may be potential candidates for single cell oil production in larger scale applications by using alternative carbon sources, combining economic and environmental benefits.
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http://dx.doi.org/10.3390/microorganisms8111809DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7698568PMC
November 2020

Mesenchymal Stromal Cells' Therapy for Polyglutamine Disorders: Where Do We Stand and Where Should We Go?

Front Cell Neurosci 2020 6;14:584277. Epub 2020 Oct 6.

CNC-Center for Neuroscience and Cell Biology, University of Coimbra, Coimbra, Portugal.

Polyglutamine (polyQ) diseases are a group of inherited neurodegenerative disorders caused by the expansion of the cytosine-adenine-guanine (CAG) repeat. This mutation encodes extended glutamine (Q) tract in the disease protein, resulting in the alteration of its conformation/physiological role and in the formation of toxic fragments/aggregates of the protein. This group of heterogeneous disorders shares common molecular mechanisms, which opens the possibility to develop a pan therapeutic approach. Vast efforts have been made to develop strategies to alleviate disease symptoms. Nonetheless, there is still no therapy that can cure or effectively delay disease progression of any of these disorders. Mesenchymal stromal cells (MSC) are promising tools for the treatment of polyQ disorders, promoting protection, tissue regeneration, and/or modulation of the immune system in animal models. Accordingly, data collected from clinical trials have so far demonstrated that transplantation of MSC is safe and delays the progression of some polyQ disorders for some time. However, to achieve sustained phenotypic amelioration in clinics, several treatments may be necessary. Therefore, efforts to develop new strategies to improve MSC's therapeutic outcomes have been emerging. In this review article, we discuss the current treatments and strategies used to reduce polyQ symptoms and major pre-clinical and clinical achievements obtained with MSC transplantation as well as remaining flaws that need to be overcome. The requirement to cross the blood-brain-barrier (BBB), together with a short rate of cell engraftment in the lesioned area and low survival of MSC in a pathophysiological context upon transplantation may contribute to the transient therapeutic effects. We also review methods like pre-conditioning or genetic engineering of MSC that can be used to increase MSC survival , cellular-free approaches-i.e., MSC-conditioned medium (CM) or MSC-derived extracellular vesicles (EVs) as a way of possibly replacing the use of MSC and methods required to standardize the potential of MSC/MSC-derived products. These are fundamental questions that need to be addressed to obtain maximum MSC performance in polyQ diseases and therefore increase clinical benefits.
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http://dx.doi.org/10.3389/fncel.2020.584277DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7573388PMC
October 2020

Spun Biotextiles in Tissue Engineering and Biomolecules Delivery Systems.

Antibiotics (Basel) 2020 Apr 12;9(4). Epub 2020 Apr 12.

Centre for Textile Science and Technology (2C2T), Department of Textile Engineering, University of Minho, Campus of Azurém, 4800-058 Guimarães, Portugal.

Nowadays, tissue engineering is described as an interdisciplinary field that combines engineering principles and life sciences to generate implantable devices to repair, restore and/or improve functions of injured tissues. Such devices are designed to induce the interaction and integration of tissue and cells within the implantable matrices and are manufactured to meet the appropriate physical, mechanical and physiological local demands. Biodegradable constructs based on polymeric fibers are desirable for tissue engineering due to their large surface area, interconnectivity, open pore structure, and controlled mechanical strength. Additionally, biodegradable constructs are also very sought-out for biomolecule delivery systems with a target-directed action. In the present review, we explore the properties of some of the most common biodegradable polymers used in tissue engineering applications and biomolecule delivery systems and highlight their most important uses.
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http://dx.doi.org/10.3390/antibiotics9040174DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7235791PMC
April 2020

Modified high-throughput Nile red fluorescence assay for the rapid screening of oleaginous yeasts using acetic acid as carbon source.

BMC Microbiol 2020 03 14;20(1):60. Epub 2020 Mar 14.

CBMA (Centre of Molecular and Environmental Biology), Department of Biology, University of Minho, Campus de Gualtar, 4710-057, Braga, Portugal.

Background: Over the last years oleaginous yeasts have been studied for several energetic, oleochemical, medical and pharmaceutical purposes. However, only a small number of yeasts are known and have been deeply exploited. The search for new isolates with high oleaginous capacity becomes imperative, as well as the use of alternative and ecological carbon sources for yeast growth.

Results: In the present study a high-throughput screening comprising 366 distinct yeast isolates was performed by applying an optimised protocol based on two approaches: (I) yeast cultivation on solid medium using acetic acid as carbon source, (II) neutral lipid estimation by fluorimetry using the lipophilic dye Nile red.

Conclusions: Results showed that, with the proposed methodology, the oleaginous potential of yeasts with broad taxonomic diversity and variety of growth characteristics was discriminated. Furthermore, this work clearly demonstrated the association of the oleaginous yeast character to the strain level, contrarily to the species-level linkage, as usually stated.
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http://dx.doi.org/10.1186/s12866-020-01742-6DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7071767PMC
March 2020

Stem Cell-Based Therapies for Polyglutamine Diseases.

Adv Exp Med Biol 2018 ;1049:439-466

Center for Neuroscience and Cell Biology, University of Coimbra, Coimbra, Portugal.

Polyglutamine (polyQ) diseases are a family of neurodegenerative disorders with very heterogeneous clinical presentations, although with common features such as progressive neuronal death. Thus, at the time of diagnosis patients might present an extensive and irreversible neuronal death demanding cell replacement or support provided by cell-based therapies. For this purpose stem cells, which include diverse populations ranging from embryonic stem cells (ESCs), to fetal stem cells, mesenchymal stromal cells (MSCs) or induced pluripotent stem cells (iPSCs) have remarkable potential to promote extensive brain regeneration and recovery in neurodegenerative disorders. This regenerative potential has been demonstrated in exciting pre and clinical assays. However, despite these promising results, several drawbacks are hampering their successful clinical implementation. Problems related to ethical issues, quality control of the cells used and the lack of reliable models for the efficacy assessment of human stem cells. In this chapter the main advantages and disadvantages of the available sources of stem cells as well as their efficacy and potential to improve disease outcomes are discussed.
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http://dx.doi.org/10.1007/978-3-319-71779-1_21DOI Listing
July 2018

Early axonal loss accompanied by impaired endocytosis, abnormal axonal transport, and decreased microtubule stability occur in the model of Krabbe's disease.

Neurobiol Dis 2014 Jun 6;66:92-103. Epub 2014 Mar 6.

Nerve Regeneration Group, IBMC - Instituto de Biologia Molecular e Celular, Rua do Campo Alegre 823, 4150-180 Porto, Portugal. Electronic address:

In Krabbe's disease (KD), a leukodystrophy caused by β-galactosylceramidase deficiency, demyelination and a myelin-independent axonopathy contributes to the severe neuropathology. Beyond axonopathy, we show that in Twitcher mice, a model of KD, a decreased number of axons both in the PNS and in the CNS, and of neurons in dorsal root ganglia (DRG), occurred before the onset of demyelination. Despite the early axonal loss, and although in vitro Twitcher neurites degenerated over time, Twitcher DRG neurons displayed an initial neurite overgrowth and, following sciatic nerve injury, Twitcher axons were regeneration-competent, at a time point where axonopathy was already ongoing. Psychosine, the toxic substrate that accumulates in KD, induced lipid raft clustering. At the mechanistic level, TrkA recruitment to lipid rafts was dysregulated in Twitcher neurons, and defective activation of the ERK1/2 and AKT pathways was identified. Besides defective recruitment of signaling molecules to lipid rafts, the early steps of endocytosis and the transport of endocytic and synaptic vesicles were impaired in Twitcher DRG neurons. Defects in axonal transport, specifically in the retrograde component, correlated with decreased levels of dynein, abnormal levels of post-translational tubulin modifications and decreased microtubule stability. The identification of the axonal defects that precede demyelination in KD, together with the finding that Twitcher axons are regeneration-competent when axonopathy is already installed, opens new windows of action to effectively correct the neuropathology that characterizes this disorder.
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http://dx.doi.org/10.1016/j.nbd.2014.02.012DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4307018PMC
June 2014

Primary bone marrow mesenchymal stromal cells rescue the axonal phenotype of Twitcher mice.

Cell Transplant 2014 Feb 27;23(2):239-52. Epub 2013 Jun 27.

Nerve Regeneration Group, Instituto de Biologia Molecular e Celular (IBMC), Porto, Portugal.

Krabbe's disease (KD) is a demyelinating disorder caused by the deficiency of lysosomal galactocerebrosidase (GALC), affecting both the central (CNS) and the peripheral nervous system (PNS). A current therapy, hematopoietic stem cell transplantation (HSCT), is ineffective at correcting the PNS pathology. We have previously shown that systemic delivery of immortalized bone marrow-derived murine mesenchymal stromal cells (BM-MSCs) diminishes the neuropathology of transplanted Twitcher mice, a murine model of KD. In this study, to move one step closer to clinical application, the effectiveness of a systematic delivery of primary BM-MSCs to promote recovery of the Twitcher PNS was assessed. Primary BM-MSCs grafted to the Twitcher sciatic nerve led to increased GALC activity that was not correlated to decreased psychosine (the toxic GALC substrate) accumulation. Nevertheless, BM-MSC transplantation rescued the axonal phenotype of Twitcher mice in the sciatic nerve, with an increased density of both myelinated and unmyelinated axons in transplanted animals. Whereas no increase in myelination was observed, upon transplantation an increased proliferation of Schwann cell precursors occurred. Supporting these findings, in vitro, BM-MSCs promoted neurite outgrowth of Twitcher sensory neurons and proliferation of Twitcher Schwann cells. Moreover, BM-MSCs expressed nerve growth factor (NGF) and brain-derived neurotrophic factor (BDNF) and promoted increased BDNF synthesis by neighboring Schwann cells. Besides their action in neurons and glia, BM-MSCs led to macrophage activation in Twitcher sciatic nerves. In summary, primary BM-MSCs diminish the neuropathology of Twitcher sciatic nerves by coordinately affecting neurons, glia, and macrophages.
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http://dx.doi.org/10.3727/096368913X669752DOI Listing
February 2014

Expression of stem cell markers: OCT4, KIT, ITGA6, and ITGB1 in the male germinal epithelium.

Syst Biol Reprod Med 2013 Oct 13;59(5):233-43. Epub 2013 Jun 13.

Department of Microscopy, Laboratory of Cell Biology, Biomedical Research Multidisciplinary Unit (UMIB), Institute of Biomedical Sciences Abel Salazar (ICBAS) , University of Porto.

Efforts have been made for the isolation and characterization of human stem spermatogonia (SG) which would be of major interest for fertility preservation in oncologic patients. We evaluated the expression of mammalian SG stem cell markers, KIT, OCT4, integrin alpha 6 (ITGA6), and integrin beta 1 (ITGB1) as possible indicators for the isolation of those cells in humans. Two different types of SG were individually isolated by micromanipulation from testicular biopsies of men with conserved spermatogenesis. Expression of mRNA showed the absence of KIT and ITGB1 markers in SG. By immunocytochemistry (IC), protein expression for KIT and integrins revealed two types of SG populations, negative (type-1) and positive (type-2). By immunohistochemistry (IH), protein expression for KIT and ITGB1 also revealed two kinds of SG populations, negative (SG A-dark) and positive (SG A-pale). Results suggest that in humans it may be possible to obtain pure populations of stem SG by using negative KIT((-))/ITGB1((-)) sorting.
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http://dx.doi.org/10.3109/19396368.2013.804964DOI Listing
October 2013

Advances and pitfalls of cell therapy in metabolic leukodystrophies.

Cell Transplant 2013 21;22(2):189-204. Epub 2012 Sep 21.

Nerve Regeneration Group, IBMC-Instituto de Biologia Molecular e Celular, 4150-180 Porto, Portugal.

Leukodystrophies are a group of disorders characterized by myelin dysfunction, either at the level of myelin formation or maintenance, that affect the central nervous system (CNS) and also in some cases, to a lesser extent, the peripheral nervous system (PNS). Although these genetic-based disorders are generally rare, all together they have a significant impact in the society, with an estimated overall incidence of 1 in 7,663 live births. Currently, there is no cure for leukodystrophies, and the development of effective treatments remains challenging. Not only leukodystrophies generally progress very fast, but also most are multifocal needing the simultaneous targeting at multiple sites. Moreover, as the CNS is affected, the blood-brain barrier (BBB) limits the efficacy of treatment. Recently, interest on cell therapy has increased, and the leukodystrophies for which metabolic correction is needed have become first-choice candidates for cell-based clinical trials. In this review, we present and discuss the available cell transplantation therapies in metabolic leukodystrophies including fucosidosis, X-linked adrenoleukodystrophy, metachromatic leukodystrophy, Canavan disease, and Krabbe's disease. We will discuss the latest advances of cell therapy and its pitfalls in this group of disorders, taking into account, among others, the limitations imposed by reduced cell migration in multifocal conditions, the need to achieve corrective enzyme threshold levels, and the growing awareness that not only myelin but also the associated axonopathy needs to be targeted in some leukodystrophies.
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http://dx.doi.org/10.3727/096368912X656117DOI Listing
January 2014

Systemic delivery of bone marrow-derived mesenchymal stromal cells diminishes neuropathology in a mouse model of Krabbe's disease.

Stem Cells 2011 Nov;29(11):1738-51

Nerve Regeneration Group, IBMC-Instituto de Biologia Molecular e Celular,Universidade do Porto, Porto, Portugal.

In Krabbe's disease, a demyelinating disorder, add-on strategies targeting the peripheral nervous system (PNS) are needed, as it is not corrected by bone-marrow (BM) transplantation. To circumvent this limitation of BM transplantation, we assessed whether i.v. delivery of immortalized EGFP(+) BM-derived murine mesenchymal stromal cells (BM-MSC(TERT-EGFP) ) targets the PNS of a Krabbe's disease model, the Twitcher mouse. In vitro, BM-MSC(TERT-EGFP) retained the phenotype of primary BM-MSC and did not originate tumors upon transplantation in nude mice. In vivo, undifferentiated EGFP(+) cells grafted the Twitcher sciatic nerve where an increase in Schwann cell precursors and axonal number was detected. The same effect was observed on BM-MSC(TERT-EGFP) i.v. delivery following sciatic nerve crush, a model of axonal regeneration. Reiterating the in vivo findings, in a coculture system, BM-MSC(TERT-EGFP) induced the proliferation of Twitcher-derived Schwann cells and the neurite outgrowth of both Twitcher-derived neurons and wild-type neurons grown in the presence of psychosine, the toxic substrate that accumulates in Krabbe's disease. In vitro, this neuritogenic effect was blocked by K252a, an antagonist of Trk receptors, and by antibody blockage of brain derived neurotrophic factor, a neurotrophin secreted by BM-MSC(TERT-EGFP) and induced in neighboring Schwann cells. In vivo, BM-MSC(TERT-EGFP) surmounted the effect of K252a, indicating their ability to act through a neurotrophin-independent mechanism. In summary, i.v. delivery of BM-MSC(TERT-EGFP) exerts a multilevel effect targeting neurons and Schwann cells, coordinately diminishing neuropathology. Therefore, to specifically target the PNS, MSC should be considered an add-on option to BM transplantation in Krabbe's disease and in other disorders where peripheral axonal loss occurs.
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http://dx.doi.org/10.1002/stem.724DOI Listing
November 2011