|  |  |  | | | | | TE-RegenMed-StemCell feed | | | | | | | | | | | | | | | | | | | Concise review: human adipose-derived stem cells: separating promise from clinical need. Stem Cells. 2011 Mar;29(3):404-11 Authors: Locke M, Feisst V, Dunbar PR Human adipose-derived stem cells (ASCs) have become an increasing interest to both stem cell biologists and clinicians because of their potential to differentiate into adipogenic, osteogenic, chondrogenic, and other mesenchymal lineages, as well as other clinically useful properties attributed to them, such as stimulation of angiogenesis and suppression of inflammation. ASCs have already been used in a number of clinical trials, and some successful outcomes have been reported, especially in tissue reconstruction. However, a critical review of the literature reveals considerable uncertainty about the true clinical potential of human ASC. First, the surgical needs that ASC might answer remain relatively few, given the current difficulties in scaling up ASC-based tissue engineering to a clinically useful volume. Second, the differentiation of ASC into cell lineages apart from adipocytes has not been conclusively demonstrated in many studies due to the use of rather simplistic approaches to the confirmation of differentiation, such as the use of nonspecific histological dyes, or a small number of molecular markers of uncertain significance. Third, the ASC prepared from human lipoaspirate for different studies differ in purity and molecular phenotype, with many studies using cell preparations that are likely to contain heterogeneous populations of cells, making it uncertain whether ASC themselves are responsible for effects observed. Hence, while one clinical application already looks convincing, the full clinical potential of ASC awaits much deeper investigation of their fundamental biology. STEM CELLS 2011,29:404-411. PMID: 21425404 [PubMed - in process] | | | | | | | | | | | | | | | | | | | | | | | | | [A two-step protocol for induction of rat adipose tissue-derived stem cells into neuron-like cells.] Nan Fang Yi Ke Da Xue Xue Bao. 2011 Mar 20;31(3):512-517 Authors: Chen PP, Zhang LH, Dong WR, Liu JM, Zhang Y, Qiao WG, Chen YH, Zhao S, Guo JS OBJECTIVE: To investigate the differentiation potential of rat adipose tissue-derived cells (ADSCs) into neuron-like cells in vitro using a two-step induction protocol. METHODS: ADSCs isolated from the epididymal fat pads in male SD rats by means of differential attachment were cultured in vitro and subjected to adipogenic induction. After flow cytometric identification of the cell surface antigens CD106, CD11b, CD45, CD49d, CD90 and CD29, the third-passage ADSCs were induced to transdifferentiate into neural stem cell (NSC)-like cells in DMEM/F12 medium containing 10 ng/ml basic fibroblast growth factor (bFGF), 20 ng/ml epidermal growth factor (EGF) and 2% B27. The resultant NSC-like cells were then induced to differentiate into neuron-like cells in the neurobasal medium containing 10 ng/ml brain-derived neurotrophic factor (BDNF), 10 ng/ml glial cell line-derived neurotrophic factor (GDNF) and 1 µmol/L retinoic acid (RA). Immunocytochemistry was employed to identify the expression of the cell surface markers nestin, MAP2 and NeuN. RESULTS: The isolated ADSCs were positive for CD90 and CD29, and oil red O staining of the induced adipose-like cells yielded positive results. The third-passage ADSCs induced for 7 days aggregated as floating cell spheres positive for NSC surface antigen nestin. Further induction in neurobasal medium for 4 h resulted in adhesion of the cell spheres and the formation of cell processes extending from some peripheral cells, suggesting a morphological resemblance to neurons. Most of the cells showed positivity for MAP2 and NeuN. CONCLUSION: ADSCs can be induced to differentiate into neuron-like cells in vitro under appropriate conditions. PMID: 21421495 [PubMed - as supplied by publisher] | | | | | | | | | | | | | | | | | | | | | | | | | Complete pulp regeneration after pulpectomy by transplantation of CD105<sup>+</sup> stem cells with SDF-1. Tissue Eng Part A. 2011 Mar 18; Authors: Iohara K, Imabayashi K, Ishizaka R, Watanabe A, Nabekura J, Ito M, Matsushita K, Nakamura H, Nakashima M Loss of pulp due to caries and pulpitis leads to loss of teeth and reduced quality of life. Thus there is an unmet need for regeneration of pulp. A promising approach is stem cell therapy. Autologous pulp stem/progenitor (CD105<sup>+</sup>) cells were transplanted into a root canal with stromal cell-derived factor (SDF)-1 following pulpectomy in mature teeth with complete apical closure in dogs. The root canal was successfully filled with regenerated pulp including nerves and vasculature by day 14, followed by new dentin formation along the dentinal wall. The newly regenerated tissue was significantly larger in the transplantation of pulp CD105<sup>+</sup>cells with SDF-1 compared with those of adipose CD105<sup>+</sup>cells with SDF-1 or unfractionated total pulp cells with SDF-1. The pulp CD105<sup>+</sup>cells highly expressed angiogenic/neurotrophic factors compared to other cells, and localized in the vicinity of newly formed capillaries after transplantation, demonstrating its potent trophic effects on neovascularization. Two dimensional electrophoretic analyses and real-time RT-PCR analyses demonstrated that the qualitative and quantitative protein and mRNA expression patterns of the regenerated pulp were similar to those of normal pulp. Thus, this novel stem cell therapy is the first demonstration of complete pulp regeneration, implying novel treatment to preserve and save teeth. PMID: 21417716 [PubMed - as supplied by publisher] | | | | | | | | | | | | | | | | | | | | | | | | | [Directional differentiation of adipose-derived stem cell]. Sheng Li Ke Xue Jin Zhan. 2010 Oct;41(5):341-6 Authors: Xiang XX, Zhao J, Li Y, Zhang WZ Adipose-derived stem cells (ADSCs) are mesenchymal stem cells (MSCs) derived from adipose tissue, which have the ability to self-renew and differentiate into many types of tissues. Here we summarize the recent advances in the research of ADSCs, introduce the methods of ADSCs isolation and culture, and discusse the factors regulating the adipo-differentiation and osteo-differentiation of ADSCs. The present review will yield novel insight relevant to the therapeutic intervention of obesity and osteo-tissue engineering. PMID: 21416923 [PubMed - in process] | | | | | | | | | | | | | | | | | | | | | | | | | Therapeutic lymphangiogenesis using stem cell and VEGF-C hydrogel. Biomaterials. 2011 Mar 19; Authors: Hwang JH, Kim IG, Lee JY, Piao S, Lee DS, Lee TS, Ra JC, Lee JY Lymphedema is a manifestation of lymphatic system insufficiency. It arises from primary lymphatic dysplasia or secondary obliteration after lymph node dissection or irradiation. Although improvement of swelling can be achieved by comprehensive non-operative therapy, treatment of this condition requires lifelong care and good compliance. Recently molecular-based treatments using VEGF-C have been investigated by several researchers. We designed the present study to determine whether the therapeutic efficacy of implanted human adipose-derived stem cells (hADSCs) could be improved by applying a gelatin hydrogel containing VEGF-C (VEGF-C hydrogel) to the site of tissue injury in a lymphedema mouse model. Four weeks after the operation, we evaluated edema and determined lymphatic vessel density at various post-operative time points. Mice treated with hADSCs and VEGF-C hydrogel showed a significantly decreased dermal edema depth compared to the groups of mice that received hADSCs only or VEGF-C hydrogel only. Immunohistochemical analysis also revealed that the hADSC/VEGF-C hydrogel group showed significantly greater lymphatic vessel regeneration than all the other groups. hADSCs were detected in the implantation sites of all mice in the hADSC/VEGF-C group, and exhibited a lymphatic endothelial differentiation phenotype as determined by co-staining PKH-labeled hADSCs for the lymphatic marker LYVE-1. Our results suggest that co-administration of hADSCs and VEGF-C hydrogel has a substantial positive effect on lymphangiogenesis. PMID: 21421266 [PubMed - as supplied by publisher] | | | | | | | | | | | | | | | | | | | | | | | | | Non-viral Delivery of Inductive and Suppressive Genes to Adipose-Derived Stem Cells for Osteogenic Differentiation. Pharm Res. 2011 Mar 19; Authors: Ramasubramanian A, Shiigi S, Lee GK, Yang F PURPOSE: To assess the effects of co-delivering osteoinductive DNA and/or small interfering RNA in directing the osteogenic differentiation of human adipose-derived stem cells (hADSCs) using a combinatorial, non-viral gene delivery approach. METHODS: hADSCs were transfected using combinations of the following genes: BMP2, siGNAS and siNoggin using poly(β-amino esters) or lipid-like molecules. A total of 15 groups were evaluated by varying DNA doses, timing of treatment, and combinations of signals. All groups were cultured in osteogenic medium for up to 37 days, and outcomes were measured using gene expression, biochemical assays, and histology. RESULTS: Biomaterials-mediated gene delivery led to a dose-dependent up-regulation of BMP2 and significant gene silencing of GNAS and Noggin in hADSCs. BMP2 alone slightly up-regulates osteogenic marker expression in hADSCs. In contrast, co-delivery of BMP2 and siGNAS or siNoggin significantly accelerates the hADSC differentiation towards osteogenic differentiation, with marked increase in bone marker expression and mineralization. CONCLUSIONS: We report a combinatorial platform for identifying synergistic interactions among multiple genetic signals associated with osteogenic differentiation of hADSCs. Our results suggest that inductive or suppressive genetic switches interact in a complex manner, and highlight the promise of combinatorial approaches towards rapidly identifying optimal signals for promoting desired stem cell differentiation. PMID: 21424160 [PubMed - as supplied by publisher] | | | | | | | | | | | | | | | | | | | | | | | | | Controlled release of cell-permeable gene complex from poly(L-lactide) scaffold for enhanced stem cell tissue engineering. J Control Release. 2011 Mar 17; Authors: Jung MR, Shim IK, Kim ES, Park YJ, Yang YI, Lee SK, Lee SJ The use of tissue engineering to deliver genes to stem cells has been impeded by low transfection efficiency of the inserted gene and poor retention at the target site. Herein, we describe the use of non-viral gene transfer by cell-permeable peptide (CPP) to increase the transfection efficiency. The combination of this technique with the use of a controlled release concept using a poly (L-lactide) scaffold allowed for prolonged uptake in stem cells. High transfection efficiency was obtained using a human-derived arginine-rich peptide denoted as Hph-1 (YARVRRRGPRR). The formation of complex between pDNA and Hph-1 was monitored using gel retardation tests to measure size and zeta potential. Complex formation was further assessed using a DNase I protection assay. A sustained gene delivery system was developed using a fibrous 3-D scaffold coated with pDNA/Hph-1 complexes. Transfection efficiency and the mean fluorescence intensity of human adipose-derived stem cells (hASCs) on the sustained delivery scaffold were compared to those of cells transfected via bolus delivery. Plasmid DNA completely bound Hph-1 at a negative-to-positive (N/P) charge ratio of 10. After complex formation, Hph-1 appeared to effectively protect pDNA against DNase I attack and exhibited cytotoxicity markedly lower than that of the pDNA/PEI complex. Plasmid DNA/Hph-1 complexes were released from the scaffolds over 14days and were successfully transfected hASCs seeded on the scaffolds. Flow cytometry revealed that the transfection efficiency in hASCs treated with pDNA/Hph-1 complex was approximately 5-fold higher than that in cells transfected using Lipofectamine. The sustained delivery system showed a significantly higher transfection efficiency and remained able to transfect cells for a longer period of time than bolus delivery. These results suggest that cell-scaffold-based tissue regeneration can be further improved by transduction concept using CPP and controlled release using polymeric scaffold. PMID: 21420455 [PubMed - as supplied by publisher] | | | | | | | | | | | | | | | | | | | | | | | | | Stem cells in drug discovery, regenerative medicine and cancer. Genome Med. 2011 Mar 14;3(3):15 Authors: Rountree CB ABSTRACT: A report on the Stem Cells World Congress held in San Diego, USA, 24-25 January 2011. PMID: 21418554 [PubMed - as supplied by publisher] | | | | | | | | | | | | | | | | | | | | | | | | | Regulation of the Matrix Microenvironment for Stem Cell Engineering and Regenerative Medicine. Ann Biomed Eng. 2011 Mar 22; Authors: Huang NF, Li S The extracellular matrix (ECM) microenvironment consists of structural and functional molecules. The ECM relays both biochemical and biophysical cues to and from the cells to modulate cell behavior and function. The biophysical cues can be engineered and applied to cells by means of spatial patterning, matrix rigidity, and matrix actuation. Tissue engineering strategies that utilize ECMs to direct stem cell organization and lineage specification show tremendous potential. This review describes the technologies for modulating ECM spatial patterning, matrix rigidity, chemical composition, and matrix actuation. The role of ECMs in vascular tissue engineering is then discussed as a model of tissue engineering and regenerative medicine. PMID: 21424849 [PubMed - as supplied by publisher] | | | | | | | | | | | | | | | | | | | | | | | | | NANOS3 function in human germ cell development. Hum Mol Genet. 2011 Mar 19; Authors: Angeles Julaton VT, Reijo Pera A Human infertility is common and frequently linked to poor germ cell development. Yet, human germ cell development is poorly understood, at least in part due to the inaccessibility of germ cells to study especially during fetal development. Here we explored the function of a highly-conserved family of genes, the NANOS genes, in the differentiation of human germ cells from human embryonic stem cells (hESCs). We observed that NANOS-1, -2 and -3 mRNAs and proteins were expressed in human gonads. We also noted that NANOS3 was expressed in germ cells throughout spermatogenesis and oogenesis and thus, focused further efforts on this family member. NANOS3 expression was highest in human germ cell nuclei where the protein co-localized with chromosomal DNA during mitosis/meiosis. Reduced expression of NANOS3 (via morpholinos or shRNA) resulted in a reduction in germ cell numbers and decreased expression of germ cell-intrinsic genes required for maintenance of pluripotency and meiotic initiation and progression. These data provide the first direct experimental evidence that NANOS3 functions in human germ cell development; indeed, NANOS3 is now one of just two genes that has been directly shown to function in germ cell development across diverse species from flies, worms, frogs, and mice to humans (the other is BOULE, a member of the DAZ gene family). Findings may contribute to our understanding of the basic biology of human germ cell development and may provide clinical insights regarding infertility. PMID: 21421998 [PubMed - as supplied by publisher] | | | | | | | | | | | | | | | | | | | | | | | | | Evaluation of risk factors in the development of stem cell therapy. J Transl Med. 2011 Mar 22;9(1):29 Authors: Herberts CA, Kwa MS, Hermsen HP ABSTRACT: Stem cell therapy holds the promise to treat degenerative diseases, cancer and repair of damaged tissues for which there are currently no or limited therapeutic options. The potential of stem cell therapies has long been recognised and the creation of induced pluripotent stem cells (iPSC) has boosted the stem cell field leading to increasing development and scientific knowledge. Despite the clinical potential of stem cell based medicinal products there are also potential and unanticipated risks. These risks deserve a thorough discussion within the perspective of current scientific knowledge and experience. Evaluation of potential risks should be a prerequisite step before clinical use of stem cell based medicinal products. The risk profile of stem cell based medicinal products depends on many risk factors, which include the type of stem cells, their differentiation status and proliferation capacity, the route of administration, the intended location, in vitro culture and/or other manipulation steps, irreversibility of treatment, need/possibility for concurrent tissue regeneration in case of irreversible tissue loss, and long-term survival of engrafted cells. Together these factors determine the risk profile associated with a stem cell based medicinal product. The identified risks (i.e. risks identified in clinical experience) or potential/theoretical risks (i.e. risks observed in animal studies) include tumour formation, unwanted immune responses and the transmission of adventitious agents. Currently, there is no clinical experience with pluripotent stem cells (i.e. embryonal stem cells and iPSC). Based on their characteristics of unlimited self-renewal and high proliferation rate the risks associated with a product containing these cells (e.g. risk on tumour formation) are considered high, if not perceived to be unacceptable. In contrast, the vast majority of small-sized clinical trials conducted with mesenchymal stem /stromal cells (MSC) in regenerative medicine applications has not reported major health concerns, suggesting that MSC therapies could be relatively safe. However, in some clinical trials serious adverse events have been reported, which emphasizes the need for additional knowledge, particularly with regard to biological mechanisms and long term safety. PMID: 21418664 [PubMed - as supplied by publisher] | | | | | | | | | | | | | | | | | | | | | | | | | Controlled Delivery Systems: From Pharmaceuticals to Cells and Genes. Pharm Res. 2011 Mar 19; Authors: Balmayor ER, Azevedo HS, Reis RL During the last few decades, a fair amount of scientific investigation has focused on developing novel and efficient drug delivery systems. According to different clinical needs, specific biopharmaceutical carriers have been proposed. Micro- and nanoparticulated systems, membranes and films, gels and even microelectronic chips have been successfully applied in order to deliver biopharmaceuticals via different anatomical routes. The ultimate goal is to deliver the potential drugs to target tissues, where regeneration or therapies (chemotherapy, antibiotics, and analgesics) are needed. Thereby, the bioactive molecule should be protected against environmental degradation. Delivery should be achieved in a dose- and time-correct manner. Drug delivery systems (DDS) have been conceived to provide improvements in drug administration such as ability to enhance the stability, absorption and therapeutic concentration of the molecules in combination with a long-term and controlled release of the drug. Moreover, the adverse effects related with some drugs can be reduced, and patient compliance could be improved. Recent advances in biotechnology, pharmaceutical sciences, molecular biology, polymer chemistry and nanotechnology are now opening up exciting possibilities in the field of DDS. However, it is also recognized that there are several key obstacles to overcome in bringing such approaches into routine clinical use. This review describes the present state-of-the-art DDS, with examples of current clinical applications, and the promises and challenges for the future in this innovative field. PMID: 21424163 [PubMed - as supplied by publisher] | | | | | | | | | | | | | | | | | | | | | | | | | Gene expression profiling in multipotent DFAT cells derived from mature adipocytes. Biochem Biophys Res Commun. 2011 Mar 15; Authors: Ono H, Oki Y, Bono H, Kano K Cellular dedifferentiation signifies the withdrawal of cells from a specific differentiated state to a stem cell-like undifferentiated state. However, the mechanism of dedifferentiation remains obscure. Here we performed comparative transcriptome analyses during dedifferentiation in mature adipocytes (MAs) to identify the transcriptional signatures of multipotent dedifferentiated fat (DFAT) cells derived from MAs. Using microarray systems, we explored similarly expressed as well as significantly differentially expressed genes in MAs during dedifferentiation. This analysis revealed significant changes in gene expression during this process, including a significant reduction in expression of genes for lipid metabolism concomitantly with a significant increase in expression of genes for cell movement, cell migration, tissue developmental processes, cell growth, cell proliferation, cell morphogenesis, altered cell shape, and cell differentiation. Our observations indicate that the transcriptional signatures of DFAT cells derived from MAs are summarized in terms of a significant decrease in functional phenotype-related genes and a parallel increase in cell proliferation, altered cell morphology, and regulation of the differentiation of related genes. A better understanding of the mechanisms involved in dedifferentiation may enable scientists to control and possibly alter the plasticity of the differentiated state, which may lead to benefits not only in stem cell research but also in regenerative medicine. PMID: 21419102 [PubMed - as supplied by publisher] | | | | | | | | | | | | | | | | | | | | | | | | | Endogenous and exogenous stem cells: a role in lung repair and use in airway tissue engineering and transplantation. J Biomed Sci. 2010;17:92 Authors: Chistiakov DA Rapid repair of the denuded alveolar surface after injury is a key to survival. The respiratory tract contains several sources of endogenous adult stem cells residing within the basal layer of the upper airways, within or near pulmonary neuroendocrine cell rests, at the bronchoalveolar junction, and within the alveolar epithelial surface, which contribute to the repair of the airway wall. Bone marrow-derived adult mesenchymal stem cells circulating in blood are also involved in tracheal regeneration. However, an organism is frequently incapable of repairing serious damage and defects of the respiratory tract resulting from acute trauma, lung cancers, and chronic pulmonary and airway diseases. Therefore, replacement of the tracheal tissue should be urgently considered. The shortage of donor trachea remains a major obstacle in tracheal transplantation. However, implementation of tissue engineering and stem cell therapy-based approaches helps to successfully solve this problem. To date, huge progress has been achieved in tracheal bioengineering. Several sources of stem cells have been used for transplantation and airway reconstitution in animal models with experimentally induced tracheal defects. Most tracheal tissue engineering approaches use biodegradable three-dimensional scaffolds, which are important for neotracheal formation by promoting cell attachment, cell redifferentiation, and production of the extracellular matrix. The advances in tracheal bioengineering recently resulted in successful transplantation of the world's first bioengineered trachea. Current trends in tracheal transplantation include the use of autologous cells, development of bioactive cell-free scaffolds capable of supporting activation and differentiation of host stem cells on the site of injury, with a future perspective of using human native sites as micro-niche for potentiation of the human body's site-specific response by sequential adding, boosting, permissive, and recruitment impulses. PMID: 21138559 [PubMed - indexed for MEDLINE] | | | | | | | | | | | | | | | | | | | | | | | | | Mandibular reconstruction using an axially vascularized tissue-engineered construct. Ann Surg Innov Res. 2011 Mar 20;5(1):2 Authors: Eweida AM, Nabawi AS, Marei MK, Khalil MR, Elhammady HA ABSTRACT: BACKGROUND: Current reconstructive techniques for continuity defects of the mandible include the use of free flaps, bone grafts, and alloplastic materials. New methods of regenerative medicine designed to restore tissues depend mainly on the so-called extrinsic neovascularization, where the neovascular bed originates from the periphery of the construct. This method is not applicable for large defects in irradiated fields. METHODS: We are introducing a new animal model for mandibular reconstruction using intrinsic axial vascularization by the Arterio-Venous (AV) loop. In order to test this model, we made cadaveric, mechanical loading, and surgical pilot studies on adult male goats. The cadaveric study aimed at defining the best vascular axis to be used in creating the AV loop in the mandibular region. Mechanical loading studies (3 points bending test) were done to ensure that the mechanical properties of the mandible were significantly affected by the designed defect, and to put a base line for further mechanical testing after bone regeneration. A pilot surgical study was done to ensure smooth operative and post operative procedures. RESULTS: The best vascular axis to reconstruct defects in the posterior half of the mandible is the facial artery (average length 32.5+/-1.9mm, caliber 2.5mm), and facial vein (average length 33.3+/-1.8mm, caliber 2.6mm). Defects in the anterior half require an additional venous graft. The defect was shown to be significantly affecting the mechanical properties of the mandible (P value 0.0204).The animal was able to feed on soft diet from the 3rd postoperative day and returned to normal diet within a week. The mandible did not break during the period of follow up (2 months). CONCLUSIONS: Our model introduces the concept of axial vascularization of mandibular constructs. This model can be used to assess bone regeneration for large bony defects in irradiated fields. This is the first study to introduce the concept of axial vascularization using the AV loop for angiogenesis in the mandibular region. Moreover, this is the first study aiming at axial vascularization of synthetic tissue engineering constructs at the site of the defect without any need for tissue transfer (in contrast to what was done previously in prefabricated flaps). PMID: 21418603 [PubMed - as supplied by publisher] | | | | | | | | | | | | | | | | | | | | | | | | | Mechanisms of fibrosis: the role of the pericyte. Curr Opin Nephrol Hypertens. 2011 Mar 18; Authors: Schrimpf C, Duffield JS PURPOSE OF REVIEW: Until recently kidney pericytes were little known. This review will update readers about key new findings concerning pericyte abundance, function in kidney vascular biology and major role in fibrogenesis. Moreover readers will become familiar with the central role of pericyte-endothelial interactions in peritubular capillary health or rarefaction and the pivotal role these may play in renal ischemia. RECENT FINDINGS: Pericytes are stromal cells that partially cover capillary walls. Pericytes were recently identified as collagen-1α1 producing cells in healthy adult kidney. Kinetic mathematical modeling studies indicated they were the source of scar-forming myofibroblasts. Comprehensive fate mapping of kidney stroma confirmed that pericytes and perivascular fibroblasts, not epithelium, were the major source of myofibroblasts. Blockade of pericyte-endothelial cross-talk in response to renal injury prevents both microvascular rarefaction and interstitial fibrosis. The detachment of pericytes from endothelium under pathological conditions and differentiation into myofibroblasts leads to pericyte deficiency at the microvascular interstitial interface, resulting in unstable microvasculature and thence vessel rarefaction, ultimately leading to nephron ischemia. To develop new therapeutic strategies, a better understanding of not only pericyte detachment and migration from capillaries, but also pericyte-endothelial crosstalk in health and injury is required. SUMMARY: This review summarizes the functional role of pericytes during fibrosis, focusing on myofibroblast origins and pericyte-endothelial cross-talk. PMID: 21422927 [PubMed - as supplied by publisher] | | | | | | | | | | | | | | | | | | | | | | | | | Variation in Mesodermal and Hematopoietic Potential of Adult Skin-derived Induced Pluripotent Stem Cell Lines in Mice. Stem Cell Rev. 2011 Mar 19; Authors: Inoue T, Kulkeaw K, Okayama S, Tani K, Sugiyama D Induced pluripotent stem cells (iPSCs) are a promising tool for regenerative medicine. Use of iPSC lines for future hematotherapy will require examination of their hematopoietic potential. Adult skin fibroblast somatic cells constitute a source of iPSCs that can be accessed clinically without ethical issues. Here, we used different methods to compare mesodermal and hematopoietic potential by embryoid body formation of five iPSC lines established from adult mouse tail-tip fibroblasts (TTFs). We observed variation in proliferation and in expression of genes (Brachyury, Tbx1, Gata1, Klf1, Csf1r) and proteins (Flk1, Ter119 and CD45) among TTF-derived lines. 256H18 iPSCs showed highest proliferation and most efficient differentiation into mesodermal and hematopoietic cells, while expression levels of the pluripotency genes Oct3/4, Sox2, Klf4 and Nanog were lowest among lines analyzed. By contrast, the 212B2 line, transduced with c-Myc, showed lowest proliferation and differentiation potential, although expression levels of Oct3/4, Sox2 and Klf4 were highest. Overall, we find that mesodermal and hematopoietic potential varies among iPSCs from an identical tissue source and that c-Myc expression likely underlies these differences. PMID: 21424235 [PubMed - as supplied by publisher] | | | | | | | | | | | | | | | | | | | | | | | | | Whole-Organ Tissue Engineering: Decellularization and Recellularization of Three-Dimensional Matrix Scaffolds. Annu Rev Biomed Eng. 2010 Jul 21; Authors: Badylak SF, Taylor D, Uygun K The definitive treatment for end stage organ failure is orthotropic transplantation. However, the demand for transplantation far exceeds the number of available donor organs. A promising tissue-engineering/regenerative-medicine approach for functional organ replacement has emerged in recent years. Decellularization of donor organs such as heart, liver, and lung can provide an acellular, naturally occurring three dimensional biologic scaffold material that can then be seeded with selected cell populations. Preliminary studies in animal models have provided encouraging results for the proof of concept. However, significant challenges for three dimensional organ engineering approach remain. This manuscript describes the fundamental concepts of whole-organ engineering, including characterization of the extracellular matrix as a scaffold, methods for decellularization of vascular organs, potential cells to reseed such a scaffold, techniques for the recellularization process and important aspects regarding bioreactor design to support this approach. Critical challenges and future directions are also discussed. Expected final online publication date for the Annual Review of Biomedical Engineering Volume 13 is July 15, 2011. Please see http://www.annualreviews.org/catalog/pubdates.aspx for revised estimates. PMID: 21417722 [PubMed - as supplied by publisher] | | | | | | | | | | | | | | | | | | | | | | | | | Organ printing: from bioprinter to organ biofabrication line. Curr Opin Biotechnol. 2011 Mar 16; Authors: Mironov V, Kasyanov V, Markwald RR Organ printing, or the layer by layer additive robotic biofabrication of functional three-dimensional tissue and organ constructs using self-assembling tissue spheroid building blocks, is a rapidly emerging technology that promises to transform tissue engineering into a commercially successful biomedical industry. It is increasingly obvious that similar well-established industries implement automated robotic systems on the path to commercial translation and economic success. The use of robotic bioprinters alone however is not sufficient for the development of large industrial scale organ biofabrication. The design and development of a fully integrated organ biofabrication line is imperative for the commercial translation of organ printing technology. This paper presents recent progress and challenges in the development of the essential components of an organ biofabrication line. PMID: 21419621 [PubMed - as supplied by publisher] | | | | | | | | | | | | | | | | | | | | | | | | | In vivo study of dendron-like nanoparticles for stem cells "tune-up": From nano to tissues. Nanomedicine. 2011 Mar 16; Authors: Oliveira JM, Sousa RA, Malafaya PB, Silva SS, Kotobuki N, Hirose M, Ohgushi H, Mano JF, Reis RL The control of stem cell differentiation to become osteoblasts in vivo is still regarded as a challenge in stem cell-based and bone tissue engineering strategies. Biodegradable dexamethasone-loaded dendron-like nanoparticles of carboxymethylchitosan/poly(amidoamine) dendrimer have been proposed as intracellular drug delivery systems of bioactive molecules. In the present work, combination of nanotechnology, stem cell engineering and tissue engineering is proposed on pre-programming the fate of rat bone marrow stromal cells (RBMSCs) towards osteoblasts cells and development of new bone tissue, in vivo. This work demonstrated that the developed nanoparticles were able to be taken up by RBMSCs, and exhibited a non-cytotoxic behavior, in vitro. The performance of the developed dendron-like nanoparticles system for the intracellular delivery of dexamethasone was investigated by seeding the engineered RBMSCs onto starch-polycaprolactone scaffolds ex vivo, and implanting subcutaneously in the back of Fischer 344/N rats (Syngeneic), in the absence of the typical osteogenic supplements. Favorable results were observed in vivo, thus suggesting that stem cells "tune-up" strategy can open up a new regenerative strategy for bone tissue engineering. PMID: 21419875 [PubMed - as supplied by publisher] | | | | | | | | | | | | | | | | | | | | | | | | | MDM4 downregulates p53 transcriptional activity and response to stress during differentiation. Cell Cycle. 2011 Apr 1;10(7) Authors: Menendez S, Goh AM, Camus S, Ng KW, Kua N, Badal V, Lane DP Embryonic stem (ES) cells are invaluable for their therapeutic potential as well as for the study of early development. Their clinical use demands an understanding of ES cell differentiation, particularly with respect to cell proliferation and the maintenance of genomic integrity, processes for which the transcription factor p53 is essential. However, although the function of p53 as a tumor suppressor has been extensively studied, its role in ES cell biology has not been clearly elucidated. To study p53 activity and regulation in differentiating ES cells, we used knock-in constructs to create a novel reporter system that provides a direct readout of p53 transcriptional activity. We thereby determine that the p53 pathway is active in ES cells, but that p53 activity and the p53-dependent stress response decrease upon differentiation. Although p53 protein levels and activity are usually primarily controlled by the ubiquitin ligase MDM2, we identify the MDM2 homolog MDM4 as the key modulator of p53 activity in differentiating ES cells. Our results provide a better understanding of ES cell regulation and could help to optimize ES cell differentiation protocols for their use in regenerative medicine. PMID: 21422812 [PubMed - as supplied by publisher] | | | | | | | | | | | | | | | | | | | | | | | | | Towards the maturation and characterization of smooth muscle cells derived from human embryonic stem cells. PLoS One. 2011;6(3):e17771 Authors: Vazão H, Neves RP, Grãos M, Ferreira L In this study we demonstrate that CD34(+) cells derived from human embryonic stem cells (hESCs) have higher smooth muscle cell (SMC) potential than CD34(-) cells. We report that from all inductive signals tested, retinoic acid (RA) and platelet derived growth factor (PDGF(BB)) are the most effective agents in guiding the differentiation of CD34(+) cells into smooth muscle progenitor cells (SMPCs) characterized by the expression of SMC genes and proteins, secretion of SMC-related cytokines, contraction in response to depolarization agents and vasoactive peptides and expression of SMC-related genes in a 3D environment. These cells are also characterized by a low organization of the contractile proteins and the contractility response is mediated by Ca(2+), which involves the activation of Rho A/Rho kinase- and Ca(2+)/calmodulin (CaM)/myosin light chain kinase (MLCK)-dependent pathways. We further show that SMPCs obtained from the differentiation of CD34(+) cells with RA, but not with PDGF(BB,) can be maturated in medium supplemented with endothelin-1 showing at the end individualized contractile filaments. Overall the hESC-derived SMCs presented in this work might be an unlimited source of SMCs for tissue engineering and regenerative medicine. PMID: 21423769 [PubMed - in process] | | | | | | | | | | | | | | | | | | | | | | | | | Analysis of intestinal fibrosis in chronic colitis in mice induced by dextran sulfate sodium. Pathol Int. 2011 Apr;61(4):228-238 Authors: Suzuki K, Sun X, Nagata M, Kawase T, Yamaguchi H, Sukumaran V, Kawauchi Y, Kawachi H, Nishino T, Watanabe K, Yoneyama H, Asakura H Fibrogenic mesenchymal cells including fibroblasts and myofibroblasts play a key role in intestinal fibrosis, however, their precise role is largely unknown. To investigate their role in intestinal fibrosis, we analyzed the lesions of chronic colitis in C57BL/6 (B6) mice induced by dextran sulfate sodium (DSS). B6 mice exposed to single cycle administration of DSS for 5 days developed acute colitis that progressed to severe chronic inflammation with dense infiltrates of mononuclear cells, irregular epithelial structure, thickening of colonic wall, and persistent deposits of collagen. Increased mRNA expressions of proinflammatory cytokines are correlated with extensive cellular infiltration, and the mRNA expressions of collagen 1, transforming growth factor (TGF)-β, and matrix metalloproteinases were also enhanced in the colon. In the colon of chronic DSS colitis, fibroblasts (vimentin(+) , α-smooth muscle actin (α-SMA)(-) ) were increased in both mucosal and submucosal layers, while myofibroblasts (vimentin(+) , α-SMA(+) ) were increased in mucosal but not in submucosal layers. Primary mouse subcutaneous fibroblast cultures experiments revealed that exogenously added TGF-β 1 substantially augmented the expressions of both vimentin and α-SMA proteins with increased production of collagen. In conclusion, profibrogenic mesenchymal cells play an important role in the development of intestinal fibrosis in this chronic DSS-induced colitis model. PMID: 21418395 [PubMed - as supplied by publisher] | | | | | | | | | | | | | | | | | | | | | | | | | Smek promotes histone deacetylation to suppress transcription of Wnt target gene brachyury in pluripotent embryonic stem cells. Cell Res. 2011 Mar 22; Authors: Lyu J, Jho EH, Lu W In embryonic stem cells (ESCs), Wnt-responsive development-related genes are silenced to maintain pluripotency and their expression is activated during differentiation. Acetylation of histones by histone acetyltransferases stimulates transcription, whereas deacetylation of histones by HDACs is correlated with transcriptional repression. Although Wnt-mediated gene transcription has been intimately linked to the acetylation or deacetylation of histones, how Wnt signaling regulates this type of histone modification is poorly understood. Here, we report that Smek, a regulatory subunit of protein phosphatase 4 (PP4) complex, plays an important role in histone deacetylation and silencing of the Wnt-responsive gene, brachyury, in ESCs. Smek mediates recruitment of PP4c and HDAC1 to the Tcf/Lef binding site of the brachyury promoter and inhibits brachyury expression in ESCs. Activation of Wnt signaling during differentiation causes disruption of the Smek/PP4c/HDAC1 complex, resulting in an increase in histones H3 and H4 acetylation at the brachyury gene locus. These results suggest that the Smek-containing PP4 complex represses transcription of Wnt-responsive development-related genes through histone deacetylation, and that this complex is essential for ESC pluripotency maintenance.Cell Research advance online publication 22 March 2011; doi:10.1038/cr.2011.47. PMID: 21423269 [PubMed - as supplied by publisher] | | | | | | | | | | | | | | | | | | | | | | | | | Viable cryopreserving tissue-engineered cell-biomaterial for cell banking therapy in an effective cryoprotectant. Tissue Eng Part C Methods. 2011 Mar 18; Authors: Umemura E, Yamada Y, Nakamura S, Ito K, Hara K, Ueda M The application of cell-biomaterial systems in tissue engineering and regenerative medicine is an important challenge in biomedicine, which preserves not only cells, but also tissue-engineered constructs. In this study, the constructs and cryoprotectant parameters were optimized, and it was evaluated whether the characteristics of dental pulp stem cells (DPSCs), which have high proliferation ability as stem cells, were maintained during encapsulation and cryopreservation. The optimal cell-biomaterial gel constructs with the gelation rate of 2% alginate: 100 mM CaCO3: 200 mM glucono-δ-lactone (GDL) = 4: 1: 1 and suitable cryoprotectants (CPAs) used for cryopreservation were Dulbecco's Modified Eagle's Medium (DMEM) supplemented with 10% ethylene glycol (EG), 1.0 M sucrose and 0.00075 M polyvinylpyrrolidone (PVP). Optimality was confirmed by cell viability (trypan blue, live/dead analysis), the proliferation of DPSCs, and the microstructure using scanning electron microscopy (SEM) in the constructs, and surface epitope by flow cytometry analysis (FACS) before and after cryopreservation. There were no visible differences in the structure. In conclusion, this study indicates that the optimal cell-biomaterial gel constructs and the cryoprotectant are promising biomaterials. The defined encapsulation/thawing system offers an excellent option for cell-banking therapy to be developed with ready-to-use viable biomaterials and patient-specific products as drug delivery systems. PMID: 21417717 [PubMed - as supplied by publisher] | | | | | | | | | | | | | | | | | | | | | | | | | Mitochondrial function controls proliferation and early differentiation potential of embryonic stem cells. Stem Cells. 2011 Mar;29(3):486-95 Authors: Mandal S, Lindgren AG, Srivastava AS, Clark AT, Banerjee U Pluripotent stem cells hold significant promise in regenerative medicine due to their unlimited capacity for self-renewal and potential to differentiate into any cell type of the body. In this study, we demonstrate that proper mitochondrial function is essential for proliferation of undifferentiated ESCs. Attenuating mitochondrial function under self-renewing conditions makes these cells more glycolytic-dependent, and it is associated with an increase in the mRNA reserves of Nanog, Oct4, and Sox2. In contrast, attenuating mitochondrial function during the first 7 days of differentiation results in normal repression of Oct4, Nanog, and Sox2. However, differentiation potential is compromised as revealed by abnormal transcription of multiple Hox genes. Furthermore, under differentiating conditions in which mitochondrial function is attenuated, tumorigenic cells continue to persist. Our results, therefore establish the importance of normal mitochondrial function in ESC proliferation, regulating differentiation, and preventing the emergence of tumorigenic cells during the process of differentiation. STEM CELLS 2011;486-495. PMID: 21425411 [PubMed - in process] | | | | | | | | | | | | | | | | | | | | | | | | | Regulation of the Matrix Microenvironment for Stem Cell Engineering and Regenerative Medicine. Ann Biomed Eng. 2011 Mar 22; Authors: Huang NF, Li S The extracellular matrix (ECM) microenvironment consists of structural and functional molecules. The ECM relays both biochemical and biophysical cues to and from the cells to modulate cell behavior and function. The biophysical cues can be engineered and applied to cells by means of spatial patterning, matrix rigidity, and matrix actuation. Tissue engineering strategies that utilize ECMs to direct stem cell organization and lineage specification show tremendous potential. This review describes the technologies for modulating ECM spatial patterning, matrix rigidity, chemical composition, and matrix actuation. The role of ECMs in vascular tissue engineering is then discussed as a model of tissue engineering and regenerative medicine. PMID: 21424849 [PubMed - as supplied by publisher] | | | | | | | | | | | | | | | | | | | | | | | | | Vascular tissue engineering: Towards the next generation vascular grafts. Adv Drug Deliv Rev. 2011 Mar 18; Authors: Naito Y, Shinoka T, Duncan D, Hibino N, Solomon D, Cleary M, Rathore A, Fein C, Church S, Breuer C The application of tissue engineering technology to cardiovascular surgery hold great promise for improving outcomes in patients with cardiovascular diseases. Currently used synthetic vascular grafts have several limitations including thrombogenicity, increased risk of infection, and lack of growth potential. We have completed the first clinical trial evaluating the feasibility of using tissue engineered vascular grafts (TEVG) created by seeding autologous bone marrow-derived mononuclear cells (BM-MNC) onto biodegradable tubular scaffolds. Despite an excellent safety profile, data from the clinical trial suggest that the primary graft related complication of the TEVG is stenosis, affecting approximately 16% of grafts within the first seven years after implantation. Continued investigation into the cellular and molecular mechanism underlying vascular neotissue formation will improve our basic understanding and provide insights that will enable the rationale design of second generation TEVG. PMID: 21421015 [PubMed - as supplied by publisher] | | | | | | | | | | | | | | | | | | | | | | | | | Bioactive glass in tissue engineering. Acta Biomater. 2011 Mar 18; Authors: Rahaman MN, Day DE, Sonny Bal B, Fu Q, Jung SB, Bonewald LF, Tomsia AP This review focuses on recent advances in the development and use of bioactive glass for tissue engineering applications. Despite its inherent brittleness, bioactive glass has several appealing characteristics as a scaffold material for bone tissue engineering. New bioactive glasses based on borate and borosilicate compositions have shown the ability to enhance new bone formation when compared to silicate bioactive glass. Borate-based bioactive glasses also have controllable degradation rates, so the degradation of the bioactive glass implant can be more closely matched to the rate of new bone formation. Bioactive glasses can be doped with trace quantities of elements such as Cu, Zn, and Sr which are known to be beneficial for healthy bone growth. In addition to the new bioactive glasses, recent advances in biomaterials processing have resulted in the creation of scaffold architectures with a range of mechanical properties suitable for the substitution of loaded as well as non-loaded bone. While bioactive glass has been extensively investigated for bone repair, there has been relatively little research on the application of bioactive glass to the repair of soft tissues. However, recent work has shown the ability of bioactive glass to promote angiogenesis, which is critical to numerous applications in tissue regeneration, such as neovascularization for bone regeneration and the healing of soft tissue wounds. Bioactive glass has also been shown to enhance neocartilage formation during in vitro culture of chondrocyte-seeded hydrogels, and to serve as a subchondral substrate for tissue-engineered osteochondral constructs. Methods used to manipulate the structure and performance of bioactive glass in these tissue engineering applications are analyzed. PMID: 21421084 [PubMed - as supplied by publisher] | | | | | | | | | | | | | | | | | | | | | | | | | Assembly and Degradation of Low-Fouling Click-Functionalized Poly(ethylene glycol)-Based Multilayer Films and Capsules. Small. 2011 Mar 21; Authors: Leung MK, Such GK, Johnston AP, Biswas DP, Zhu Z, Yan Y, Lutz JF, Caruso F Nano-/micrometer-scaled films and capsules made of low-fouling materials such as poly(ethylene glycol) (PEG) are of interest for drug delivery and tissue engineering applications. Herein, the assembly and degradation of low-fouling, alkyne-functionalized PEG (PEG(Alk) ) multilayer films and capsules, which are prepared by combining layer-by-layer (LbL) assembly and click chemistry, are reported. A nonlinear, temperature-responsive PEG(Alk) is synthesized, and is then used to form hydrogen-bonded multilayers with poly(methacrylic acid) (PMA) at pH 5. The thermoresponsive behavior of PEG(Alk) is exploited to tailor film buildup by adjusting the assembly conditions. Using alkyne-azide click chemistry, PEG(Alk) /PMA multilayers are crosslinked with a bisazide linker that contains a disulfide bond, rendering these films and capsules redox-responsive. At pH 7, by disrupting the hydrogen bonding between the polymers, PEG(Alk) LbL films and PEG(Alk) -based capsules are obtained. These films exhibit specific deconstruction properties under simulated intracellular reducing conditions, but remain stable at physiological pH, suggesting potential applications in controlled drug release. The low-fouling properties of the PEG films are confirmed by incubation with human serum and a blood clot. Additionally, these capsules showed negligible toxicity to human cells. PMID: 21425467 [PubMed - as supplied by publisher] | | | | | | | | | | | | | | | | | | | | | | | | | Cell behavior on protein matrices containing laminin α1 peptide AG73. Biomaterials. 2011 Mar 18; Authors: Yamada Y, Katagiri F, Hozumi K, Kikkawa Y, Nomizu M Collagen has been widely used for tissue engineering. Here, we applied bioactive laminin-derived peptides as an additive for collagen, laminin-111, and fibronectin matrices resulting in peptide/collagen, peptide/laminin-111, and peptide/fibronectin matrices. Several syndecan-binding peptides, including AG73 (RKRLQVQLSIRT), enhanced the cell attachment activity of collagen matrices. AG73 synergistically enhanced not only cell attachment but also cell spreading on collagen matrices. AG73 also enhanced integrin-binding to the collagen matrices, including organization of actin stress fibers and promotion of Tyr397-focal adhesion kinase (FAK) phosphorylation. Additionally, AG73 enhanced neurite outgrowth on collagen matrices. These results suggest that the integrin-mediated biological activity of collagen matrices is synergistically enhanced by the syndecan-mediated cellular function of AG73. Further, cell attachment and spreading activity of laminin-111 and fibronectin matrices was also synergistically enhanced by AG73. The syndecan-binding peptides are useful to enhance the integrin-mediated biological activities of extracellular matrix (ECM) proteins, such as collagen, laminin-111, and fibronectin. The peptide/matrix mixed method is a new concept for biomaterial fabrication and has the potential for wide use in cell and tissue engineering. PMID: 21420730 [PubMed - as supplied by publisher] | | | | | | | | | | | | | | | | | | | | | | | | | The combined bone forming capacity of human periosteal derived cells and calcium phosphates. Biomaterials. 2011 Mar 19; Authors: Roberts SJ, Geris L, Kerckhofs G, Desmet E, Schrooten J, Luyten FP Current knowledge suggests that the periosteum, a fibrous tissue which covers the surface of all bones, contains a population of progenitor cells which mediate the repair of bone defects. In an effort to optimise the utilisation of this source of cells for bone engineering, herein we describe the rational selection of calcium phosphate (CaP) containing materials, based on biomaterial properties, and evaluation of their combined bone forming capacity. Five different commercially available orthopaedic 3D matrices composed of CaP particles in an open collagen network (NuOss™, CopiOs™, Bio-Oss(®), Collagraft™ and Vitoss(®)) were evaluated in vitro and in vivo with human periosteal derived cells (hPDCs). It was found that the cell-material combinations behaved quite differently in vivo, despite apparent in vitro similarities in gene expression profiles. Bone formation was highest within the NuOss™/hPDC implant at 13.03%, which also contained the highest incidence of bone marrow formation. The bone formed in this implant was chimeric with approximately 65% originating from implanted cells. Upon analysis of human specific gene expression, although it was found that predominantly osteogenic differentiation was observed within NuOss™/hPDC implants, a lesser induction of chondrogenic genes was also observed. The formation of a cartilage intermediate was confirmed by histology. Additionally the NuOss™/hPDC implant integrated into the mouse environment with apparent active scaffold resorption. This study demonstrates the importance of matching a cell support/biological matrix with a cell type and subsequently has outlined parameters which can be used for the rational selection of biomaterials for bone engineering. PMID: 21421268 [PubMed - as supplied by publisher] | | | | | | | | | | | | | | | | | | | | | | | | | [Tissue engineering of heart valves.] Chirurg. 2011 Mar 20; Authors: Akhyari P, Minol P, Assmann A, Barth M, Kamiya H, Lichtenberg A With the introduction of heart valve prostheses cardiac valvular disease has become much more accessible to therapeutic options. However, currently available prostheses display significant limitations, such as limited long-term durability (biological prostheses) and a long-term necessity for anticoagulation therapy. Hence, alternative prosthesis types have been extensively explored in recent years particularly aiming at the development of vital and regenerative prostheses by means of tissue engineering. In the scientific field, different competing concepts have been introduced, including biological or synthetic scaffolds which can be further enhanced by cellular or extracellular components to promote further in vivo development of the prosthesis after implantation. Nowadays, decellularized donor heart valves are among the most advanced prosthesis types experiencing growing clinical attention and widespread use. PMID: 21424291 [PubMed - as supplied by publisher] | | | | | | | | | | | | | | | | | | | | | | | | | [Biological characteristics of human umbilical cord-derived mesenchymal stem cells and their differentiation into chondrogenic and osteogenic cells.] Zhonghua Yi Xue Za Zhi. 2011 Feb;91(5):317-321 Authors: Zhao QH, Zhu JX, Wang L, Dong SH, Xia T, Tian JW OBJECTIVE: To investigate the isolation and expansion of mesenchymal stem cells (MSCS) from human umibilical cord Wharton's jelly and their biological identities, and explore the possibility of inducing human umbilical cord-derived MSCS to differentiate into chondrogenic and osteogenic cells. METHODS: The hUCMSCs were isolated form human umbilical cord by tissue adherence and digested with collagenaseNB4, dispase II and hyaluronidase. The morphology, proliferation and immunophenotype of the 3rd passage cells were analyzed, and then the chondrogenic and osteogenic differentiation was tested and evaluated by specific staining methods.cells were induced to chondrogenic and osteogenic differentiation in vitro. RESULTS: The isolation of hUCMSCs by digestion with collagenaseNB4, dispase II and hyaluronidase was efficient. After seeded for 24 hours, the adherent cells showed spindle shape and fibroblast cell-like shape and the size of hUCMSCs was homogeneous. Flow cytometry analysis revealed that the hUCMSCs were positive for CD44, CD105, CD90, CD73, but were negative for CD45, CD34, CD14, CD19 and HLA-DR. These cells could be induced to differentiate into chondrogenic and osteogenic cells under proper inducing conditions. The hUCMSCs retained the appearance and phenotype even after being expanded more than 40 passages in vitro. CONCLUSIONS: The human MSCs could be isolated from human umbilical cord Wharton's jelly, and it was easy to propagate these MSCs. An in vitro method for isolation and purification of hUCMSCs from human umbilical cord has been established. The cultured cells were composed of only undifferentiated cells and their biological properties were stable. The hUCMSCs are expected to be a new type of stem cells of tissue engineering. PMID: 21419006 [PubMed - as supplied by publisher] | | | | | | | | | | | | | | | | | | | | | | | | | Controlled Delivery Systems: From Pharmaceuticals to Cells and Genes. Pharm Res. 2011 Mar 19; Authors: Balmayor ER, Azevedo HS, Reis RL During the last few decades, a fair amount of scientific investigation has focused on developing novel and efficient drug delivery systems. According to different clinical needs, specific biopharmaceutical carriers have been proposed. Micro- and nanoparticulated systems, membranes and films, gels and even microelectronic chips have been successfully applied in order to deliver biopharmaceuticals via different anatomical routes. The ultimate goal is to deliver the potential drugs to target tissues, where regeneration or therapies (chemotherapy, antibiotics, and analgesics) are needed. Thereby, the bioactive molecule should be protected against environmental degradation. Delivery should be achieved in a dose- and time-correct manner. Drug delivery systems (DDS) have been conceived to provide improvements in drug administration such as ability to enhance the stability, absorption and therapeutic concentration of the molecules in combination with a long-term and controlled release of the drug. Moreover, the adverse effects related with some drugs can be reduced, and patient compliance could be improved. Recent advances in biotechnology, pharmaceutical sciences, molecular biology, polymer chemistry and nanotechnology are now opening up exciting possibilities in the field of DDS. However, it is also recognized that there are several key obstacles to overcome in bringing such approaches into routine clinical use. This review describes the present state-of-the-art DDS, with examples of current clinical applications, and the promises and challenges for the future in this innovative field. PMID: 21424163 [PubMed - as supplied by publisher] | | | | | | | | | | | | | | | | | | | | | | | | | Flexible polymeric ultrathin film for mesenchymal stem cells differentiation. Acta Biomater. 2011 Mar 18; Authors: Pensabene V, Taccola S, Ricotti L, Ciofani G, Menciassi A, Perut F, Salerno M, Dario P, Baldini N Ultrathin films (also called nanofilms) are 2D polymeric structures with potential application in biology, biotechnology, cosmetics and tissue engineering. Since they can be handled in liquid with common micropipettes or tweezers, they have been proposed as flexible systems for cell adhesion and proliferation. In particular, aiming to design a novel patch for bone or tendon repair and healing, in this work the biocompatibility, adhesion and proliferation activity of Saos-2, MRC-5, human and rat mesenchymal stem cells (MSCs) on poly-lactic acid nanofilms were evaluated. The nanofilms did not impair the cell growth and differentiation in osteoblasts and chondrocytes. Moreover nanofilms adhesion on articulation of rabbit was evidenced in ex vivo conditions. The ease to handle, the flexibility and the biocompatibility of these nanofilms thus represent favorable aspects for their potential employment in minimally invasive surgical procedures as flexible carrier of stem cells or as repairing system able to locally deliver drugs. PMID: 21421086 [PubMed - as supplied by publisher] | | | | | | | | | | | | | | | | | | | | | | | | | Controlled release of cell-permeable gene complex from poly(L-lactide) scaffold for enhanced stem cell tissue engineering. J Control Release. 2011 Mar 17; Authors: Jung MR, Shim IK, Kim ES, Park YJ, Yang YI, Lee SK, Lee SJ The use of tissue engineering to deliver genes to stem cells has been impeded by low transfection efficiency of the inserted gene and poor retention at the target site. Herein, we describe the use of non-viral gene transfer by cell-permeable peptide (CPP) to increase the transfection efficiency. The combination of this technique with the use of a controlled release concept using a poly (L-lactide) scaffold allowed for prolonged uptake in stem cells. High transfection efficiency was obtained using a human-derived arginine-rich peptide denoted as Hph-1 (YARVRRRGPRR). The formation of complex between pDNA and Hph-1 was monitored using gel retardation tests to measure size and zeta potential. Complex formation was further assessed using a DNase I protection assay. A sustained gene delivery system was developed using a fibrous 3-D scaffold coated with pDNA/Hph-1 complexes. Transfection efficiency and the mean fluorescence intensity of human adipose-derived stem cells (hASCs) on the sustained delivery scaffold were compared to those of cells transfected via bolus delivery. Plasmid DNA completely bound Hph-1 at a negative-to-positive (N/P) charge ratio of 10. After complex formation, Hph-1 appeared to effectively protect pDNA against DNase I attack and exhibited cytotoxicity markedly lower than that of the pDNA/PEI complex. Plasmid DNA/Hph-1 complexes were released from the scaffolds over 14days and were successfully transfected hASCs seeded on the scaffolds. Flow cytometry revealed that the transfection efficiency in hASCs treated with pDNA/Hph-1 complex was approximately 5-fold higher than that in cells transfected using Lipofectamine. The sustained delivery system showed a significantly higher transfection efficiency and remained able to transfect cells for a longer period of time than bolus delivery. These results suggest that cell-scaffold-based tissue regeneration can be further improved by transduction concept using CPP and controlled release using polymeric scaffold. PMID: 21420455 [PubMed - as supplied by publisher] | | | | | | | | | | | | | | | | | | | | | | | | | [Tissue engineering in cardiac surgery.] Chirurg. 2011 Mar 18; Authors: Haverich A PMID: 21424285 [PubMed - as supplied by publisher] | | | | | | | | | | | | | | | | | | | | | | | | | [Cell sources for cardiovascular tissue engineering.] Chirurg. 2011 Mar 16; Authors: Klopsch C, Donndorf P, Kaminski A, Ma N, Steinhoff G Numerous studies have confirmed that stem cell therapy has significant potential for the regeneration of congenital and acquired heart diseases. The utilization of embryonic stem cells and induced pluripotent stem cells promises a possible generation and regeneration of all cardiovascular structures. On the one hand fetal and adult stem cells, e.g. endothelial progenitors, mesenchymal, hematopoietic, cardiac stem cells and myoblasts, possess limited potential for multilinear differentiation. On the other hand these cells have high paracrin activity and support with well-confirmed safety the reconstruction and formation of cardiovascular structures. On the visionary track towards an autonomously functioning autologous heart generated by tissue engineering, vascular, valvular and myocardial tissues have already been successfully created. This manuscript describes the possible stem cell sources for cardiovascular tissue engineering and evaluates their potency and safety from a medical and ethical point of view employing the data from systematic reviews (Medline database) and own investigations. PMID: 21424292 [PubMed - as supplied by publisher] | | | | | | | | | | | | | | | | | | | | | | | | | Hydrogen sulfide causes apoptosis in human pulp stem cells. J Endod. 2011 Apr;37(4):479-84 Authors: Kobayashi C, Yaegaki K, Calenic B, Ishkitiev N, Imai T, Ii H, Aoyama I, Kobayashi H, Izumi Y, Haapasalo M Untreated dental caries will eventually lead to pulpal inflammation. Although much is known regarding the interaction of microbial antigens and the immunologic defense systems of pulp, many aspects of the pathogenesis of pulpitis are not fully understood. The relationship between human pulp stem cells (HPSCs) and the pathogenesis of pulpitis remains among the poorly understood areas. Many of the invading bacteria are known to produce considerable amounts of hydrogen sulfide (H(2)S), which causes apoptosis in some tissues. The aims of this study were to determine whether H(2)S causes apoptosis in HPSCs and to examine its signaling pathway. PMID: 21419294 [PubMed - in process] | | | | | | | | | | | | | | | | | | | | | | | | | Organ printing: from bioprinter to organ biofabrication line. Curr Opin Biotechnol. 2011 Mar 16; Authors: Mironov V, Kasyanov V, Markwald RR Organ printing, or the layer by layer additive robotic biofabrication of functional three-dimensional tissue and organ constructs using self-assembling tissue spheroid building blocks, is a rapidly emerging technology that promises to transform tissue engineering into a commercially successful biomedical industry. It is increasingly obvious that similar well-established industries implement automated robotic systems on the path to commercial translation and economic success. The use of robotic bioprinters alone however is not sufficient for the development of large industrial scale organ biofabrication. The design and development of a fully integrated organ biofabrication line is imperative for the commercial translation of organ printing technology. This paper presents recent progress and challenges in the development of the essential components of an organ biofabrication line. PMID: 21419621 [PubMed - as supplied by publisher] | | | | | | | | | | | | | | | | | | | | | | | | | Concise review: human adipose-derived stem cells: separating promise from clinical need. Stem Cells. 2011 Mar;29(3):404-11 Authors: Locke M, Feisst V, Dunbar PR Human adipose-derived stem cells (ASCs) have become an increasing interest to both stem cell biologists and clinicians because of their potential to differentiate into adipogenic, osteogenic, chondrogenic, and other mesenchymal lineages, as well as other clinically useful properties attributed to them, such as stimulation of angiogenesis and suppression of inflammation. ASCs have already been used in a number of clinical trials, and some successful outcomes have been reported, especially in tissue reconstruction. However, a critical review of the literature reveals considerable uncertainty about the true clinical potential of human ASC. First, the surgical needs that ASC might answer remain relatively few, given the current difficulties in scaling up ASC-based tissue engineering to a clinically useful volume. Second, the differentiation of ASC into cell lineages apart from adipocytes has not been conclusively demonstrated in many studies due to the use of rather simplistic approaches to the confirmation of differentiation, such as the use of nonspecific histological dyes, or a small number of molecular markers of uncertain significance. Third, the ASC prepared from human lipoaspirate for different studies differ in purity and molecular phenotype, with many studies using cell preparations that are likely to contain heterogeneous populations of cells, making it uncertain whether ASC themselves are responsible for effects observed. Hence, while one clinical application already looks convincing, the full clinical potential of ASC awaits much deeper investigation of their fundamental biology. STEM CELLS 2011,29:404-411. PMID: 21425404 [PubMed - in process] | | | | | | | | | | | | | | | | | | | | | | | | | In vivo study of dendron-like nanoparticles for stem cells "tune-up": From nano to tissues. Nanomedicine. 2011 Mar 16; Authors: Oliveira JM, Sousa RA, Malafaya PB, Silva SS, Kotobuki N, Hirose M, Ohgushi H, Mano JF, Reis RL The control of stem cell differentiation to become osteoblasts in vivo is still regarded as a challenge in stem cell-based and bone tissue engineering strategies. Biodegradable dexamethasone-loaded dendron-like nanoparticles of carboxymethylchitosan/poly(amidoamine) dendrimer have been proposed as intracellular drug delivery systems of bioactive molecules. In the present work, combination of nanotechnology, stem cell engineering and tissue engineering is proposed on pre-programming the fate of rat bone marrow stromal cells (RBMSCs) towards osteoblasts cells and development of new bone tissue, in vivo. This work demonstrated that the developed nanoparticles were able to be taken up by RBMSCs, and exhibited a non-cytotoxic behavior, in vitro. The performance of the developed dendron-like nanoparticles system for the intracellular delivery of dexamethasone was investigated by seeding the engineered RBMSCs onto starch-polycaprolactone scaffolds ex vivo, and implanting subcutaneously in the back of Fischer 344/N rats (Syngeneic), in the absence of the typical osteogenic supplements. Favorable results were observed in vivo, thus suggesting that stem cells "tune-up" strategy can open up a new regenerative strategy for bone tissue engineering. PMID: 21419875 [PubMed - as supplied by publisher] | | | | | | | | | | | | | | | | | | | | | | | | | [Tissue engineering of vascularized myocardial prosthetic tissue : Biological and solid matrices.] Chirurg. 2011 Mar 16; Authors: Schilling T, Cebotari S, Tudorache I, Haverich A Tissue engineering of bioartificial myocardial tissue will become an increasingly important therapeutic approach in the near future but supply of oxygen and nutrients as well as evacuation of metabolic products represent a critical obstacle in tissues with a thickness of 100 µm and above. Viability of seeded cells in the myocardial patch is positively correlated with its function and thus early sufficient vascularization is mandatory. The choice of substrate, structure of matrices, specific cellular seeding and addition of growth factors contribute to this necessary vascularization process.This review article gives an overview of the current state of research on recent myocardial tissue engineering utilizing natural and solid substrates (urinary bladder, gall bladder, small intestine, stomach, peritoneum, omentum, uterus, skeletal muscle, diaphragm and cardiac muscle) with a special focus on the results of vascularization of bioartificial tissue for each approach. PMID: 21424290 [PubMed - as supplied by publisher] | | | | | | | | | | | | | | | | | | | | | | | | | Towards the maturation and characterization of smooth muscle cells derived from human embryonic stem cells. PLoS One. 2011;6(3):e17771 Authors: Vazão H, Neves RP, Grãos M, Ferreira L In this study we demonstrate that CD34(+) cells derived from human embryonic stem cells (hESCs) have higher smooth muscle cell (SMC) potential than CD34(-) cells. We report that from all inductive signals tested, retinoic acid (RA) and platelet derived growth factor (PDGF(BB)) are the most effective agents in guiding the differentiation of CD34(+) cells into smooth muscle progenitor cells (SMPCs) characterized by the expression of SMC genes and proteins, secretion of SMC-related cytokines, contraction in response to depolarization agents and vasoactive peptides and expression of SMC-related genes in a 3D environment. These cells are also characterized by a low organization of the contractile proteins and the contractility response is mediated by Ca(2+), which involves the activation of Rho A/Rho kinase- and Ca(2+)/calmodulin (CaM)/myosin light chain kinase (MLCK)-dependent pathways. We further show that SMPCs obtained from the differentiation of CD34(+) cells with RA, but not with PDGF(BB,) can be maturated in medium supplemented with endothelin-1 showing at the end individualized contractile filaments. Overall the hESC-derived SMCs presented in this work might be an unlimited source of SMCs for tissue engineering and regenerative medicine. PMID: 21423769 [PubMed - in process] | | | | | | | | | | | | | | | | | | | | | | | | | [Progresses of in vitro culture and differentiation in conjunctival epithelial stem cells.] Zhonghua Yan Ke Za Zhi. 2011 Jan;47(1):79-82 Authors: Li WW, Sun XG Conjunctiva epithelial stem cells are bipotent cells giving rise to both conjunctival epithelial cells and goblet cells. They play a central role in ocular surface homeostasis and wound repair, and also have great capacities of self-renewal, proliferation and differentiation. As a result, conjunctival epithelial stem cells are main resources of seed cells for tissue engineering conjunctiva. To review the current research of conjunctival epithelia stem cells such as their features, distribution, ways to identify stem cells, in vitro culture and induced differentiation to goblet cells. PMID: 21418932 [PubMed - as supplied by publisher] | | | | | | | | | | | | | | | | | | | | | | | | Simmering under the surface of California's financial crisis is the possiblity that the state's $3 billion stem cell agency could become a victim, waylaid as state leaders look for more ways to cut state spending.
Lawmakers and others are discussing the likelihood of a continued suspension of sales of state bonds, which are the lifeblood of the $3 billion California stem cell agency. Without | | | | | | | | | |  | |  | |  |
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