|  |  |  | | | | | TE-RegenMed-StemCell feed | | | | | | | | | | | | | | | | | | | The influence of fibrous elastomer structure and porosity on matrix organization. PLoS One. 2010;5(12):e15717 Authors: Ifkovits JL, Wu K, Mauck RL, Burdick JA Fibrous scaffolds are finding wide use in the field of tissue engineering, as they can be designed to mimic many native tissue properties and structures (e.g., cardiac tissue, meniscus). The influence of fiber alignment and scaffold architecture on cellular interactions and matrix organization was the focus of this study. Three scaffolds were fabricated from the photocrosslinkable elastomer poly(glycerol sebacate) (PGS), with changes in fiber alignment (non-aligned (NA) versus aligned (AL)) and the introduction of a PEO sacrificial polymer population to the AL scaffold (composite (CO)). PEO removal led to an increase in scaffold porosity and maintenance of scaffold anisotropy, as evident through visualization, mechanical testing, and mass loss studies. Hydrated scaffolds possessed moduli that ranged between ∼3-240 kPa, failing within the range of properties (<300 kPa) appropriate for soft tissue engineering. CO scaffolds were completely degraded as early as 16 days, whereas NA and AL scaffolds had ∼90% mass loss after 21 days when monitored in vitro. Neonatal cardiomyocytes, used as a representative cell type, that were seeded onto the scaffolds maintained their viability and aligned along the surface of the AL and CO fibers. When implanted subcutaneously in rats, a model that is commonly used to investigate in vivo tissue responses to biomaterials, CO scaffolds were completely integrated at 2 weeks, whereas ∼13% and ∼16% of the NA and AL scaffolds, respectively remained acellular. However, all scaffolds were completely populated with cells at 4 weeks post-implantation. Polarized light microscopy was used to evaluate the collagen elaboration and orientation within the scaffold. An increase in the amount of collagen was observed for CO scaffolds and enhanced alignment of the nascent collagen was observed for AL and CO scaffolds compared to NA scaffolds. Thus, these results indicate that the scaffold architecture and porosity are important considerations in controlling tissue formation. PMID: 21203510 [PubMed - in process] | | | | | | | | | | | | | | | | | | | | | | | | | Adipose-Derived Stem Cells for Wound Healing Applications. Ann Plast Surg. 2010 Dec 30; Authors: Cherubino M, Rubin JP, Miljkovic N, Kelmendi-Doko A, Marra KG Nonhealing wounds remain a significant challenge for plastic surgeons. More than 600,000 people suffer from venous ulcers and 1.5 to 3 million people are being treated for pressure sores every year in the United States. The use of tissue engineering techniques such as stem-cell therapy and gene therapy to improve wound healing is a promising strategy. Adipose tissue represents a source of cells that may be able to enhance wound healing. Adipose-derived stem cells (ASCs) are adult stem cells that are easily harvested and of great interest for plastic surgeons. Specifically, ASCs secrete angiogenic growth factors that can induce tissue regeneration. This review describes innovative research strategies using ASCs therapies for treatment of chronic, nonhealing wounds. PMID: 21200308 [PubMed - as supplied by publisher] | | | | | | | | | | | | | | | | | | | | | | | | | Behaviour of mesenchymal stem cells, fibroblasts and osteoblasts on smooth surfaces. Acta Biomater. 2010 Dec 31; Authors: Lavenus S, Pilet P, Guicheux J, Weiss P, Louarn G, Layrolle P Understanding of the interactions between cells and surfaces is essential in the field of tissue engineering and biomaterials. This study aimed to compare the adhesion, proliferation and differentiation of human mesenchymal stem cells (hMSC), osteoblast cell-line (MC3T3-E1) and gingival fibroblasts (HGF-1) on tissue culture polystyrene (TCPS), glass and titanium (Ti). The average surface roughness was 5, 0.2 and 40 10(-3) μm for TCPS, Glass and Ti, respectively. Immunocytochemistry and image analysis made it possible to quantify the number and morphology of adherent cells as well as the density of the focal points. Regardless of the substrate, both hMSC and osteoblastic cells were mainly branch-shaped. HGF-1 exhibited a significantly higher number of focal points on Ti than on TCPS and glass. Alizarin red quantification indicated that both hMSC and osteoblastic cells were more differentiated on TCPS than on Ti and glass. The surface properties of substrates, such as roughness, wettability and chemical composition, modulated the behaviour of the cells. Early events, such as cell adhesion, may influence the differentiation of hMSC and consequently tissue healing around implanted biomaterials. PMID: 21199693 [PubMed - as supplied by publisher] | | | | | | | | | | | | | | | | | | | | | | | | | Endothelial Progenitor Cells are integrated in newly formed capillaries and alter adjacent fibrovascular tissue after subcutaneous implantation in a fibrin matrix. J Cell Mol Med. 2010 Dec 28; Authors: Bleiziffer O, Hammon M, Naschberger E, Lipnik K, Arkudas A, Rath S, Pryymachuk G, Beier JP, Stürzl M, Horch RE, Kneser U Vascularisation of bioartificial matrices is crucial for successful tissue engineering. Endothelial progenitor cells (EPC) have shown vascularisation potential in ischemic conditions and may also support blood vessel formation in tissue-engineered matrices. The aim of our study was to investigate the impact of a well-characterized murine embryonal EPC line (T17b-EPC) on vascularisation and fibrovascular granulation tissue formation after suspension in a fibrine matrix followed by subcutaneous implantation in a separation chamber in rats. EPC were fluorescently labelled in vitro prior to implantation. After 3, 7 or 14 days, animals were sacrificed followed by explantation and histological analysis of the constructs. Before the end of the experiment, BS-I lectin was intravenously injected to mark the vascular ingrowth into the implanted constructs. The transplanted cells were histologically detected at all time points and located almost exclusively within the fibrin matrix at day 3 but the number of cells in the clot continuously decreased over day 7 to day 14. Conversely, cells were detected within the newly formed granulation tissue in increasing numbers from day 3 over day 7 to day 14. Transplanted cells were also found in the intermuscular septa. Cell viability was confirmed by use of an EPC clone expressing β-galactosidase. Fluorescence microscopy demonstrated integration of the transplanted cells in newly formed blood vessels within the fibrovascular granulation tissue adjacent to the fibrin clot. Presence of cells in the fibrin clot lead to thicker granulation tissue and an increased blood vessel diameter compared to cell-free controls. Organ standard controls showed presence of the transplanted cells in spleens at day 14 after transplantation. In summary, EPC exhibited biological activity after subcutaneous implantation in a fibrin matrix by migration from the fibrin clot into the granulation tissue and along intermuscular septae, undergoing differentiation into mature endothelial cells and integration into newly formed blood vessels and altering fibrovascular granulation tissue development. EPC may hold promise to modulate blood vessel formation in bioartificial matrices. PMID: 21199325 [PubMed - as supplied by publisher] | | | | | | | | | | | | | | | | | | | | | | | | | Early spontaneous immortalization and loss of plasticity of rabbit bone marrow mesenchymal stem cells. Cell Prolif. 2011 Feb;44(1):67-74 Authors: Ahmadbeigi N, Shafiee A, Seyedjafari E, Gheisari Y, Vassei M, Amanpour S, Amini S, Bagherizadeh I, Soleimani M Objectives: Bone marrow-derived mesenchymal stem cells (BM-MSC) have been widely used for cell therapy and tissue engineering purposes. However, there are still controversies concerning safety of application of these cells after in vitro expansion. Therefore, we aimed to investigate the characteristics of rabbit BM-MSC during long-term culture. Materials and methods: In this study, we have examined growth kinetics, morphological changes, differentiation potential and chromosomal abnormalities, as well as tumour formation potential of rabbit BM-MSC in long-term culture. Results and conclusion: We found that shortly after isolation, proliferation rate of rabbit BM-MSC decreases until they enter a dormant phase. During this period of quiescence, the cells are large and multinucleate. After some weeks of dormancy we found that several small mononuclear cells originated from each large multinucleate cell. These newly formed cells proliferated rapidly but had inferior differentiation potential. Although they were immortal, they did not have the capability for tumour formation in soft agar assay or in nude mice. This is the first report of spontaneous, non-tumorigenic immortalization of BM-MSC in rabbits. The phenomenon raises more concern for meticulous monitoring and quality control for using rabbit BM-MSC in cell-based therapies and tissue engineering experiments. PMID: 21199011 [PubMed - as supplied by publisher] | | | | | | | | | | | | | | | | | | | | | | | | | Influence of space-filling materials in subantral bone augmentation: blood clot vs. autogenous bone chips vs. bovine hydroxyapatite. Clin Oral Implants Res. 2010 Dec 28; Authors: Lambert F, Léonard A, Drion P, Sourice S, Layrolle P, Rompen E Aim: The first objective of the present study was to compare the short- and long-term 3D volume stability of sub-sinusal bone regeneration in rabbits using different space fillers. The second objective was to assess qualitatively and quantitatively the early bone formation process and long-term behavior of the regenerated bone. Materials and methods: Fifteen rabbits underwent a double sinus lift procedure using: blood clot (Clot), autogenous bone chips (Auto) and bovine hydroxyapatite (BHA). Animals were euthanized at 1 week, 5 weeks and 6 months. Samples were subjected to X-ray microtomography and histology. Variations in the volume of bone augmentations were calculated at different time points. Qualitative analysis was performed using 7 μm sections and quantitative histomorphometric analyses were carried out using scanning electron microscopy. Results: From baseline (100%) to 5 weeks, the augmented volumes declined to 17.3% (Clot), 57.6% (Auto) and 90.6% (BHA). After 6 months, only 19.4% (Clot) and 31.4% (Auto) of initial volumes were found, while it remained more stable in the BHA group (84%). At 1 week, an initial osteogenesis process could be observed in the three groups along the bone walls. At 5 weeks, despite a significant decline in the volume, newly formed bone density was higher with Clot and Auto than with BHA. At 6 months, bone densities were statistically similar in the three groups. However, after 6 months, the surface invaded by newly formed bone (regenerated area) was significantly higher when BHA was used as space filler. In the BHA group, the biomaterial area slightly decreased from 42.7% (1 week) to 40% (5 weeks) and 34.9% (6 months) and the density of the composite regenerated tissue (bone+BHA) reached >50% at 6 months. Conclusions and clinical implications: The three space fillers allowed bone formation to occur. Nevertheless, augmented volumes declined in the Clot and Auto groups, while they remained stable with BHA. A slowly resorbable biomaterial might be suitable in sub-sinusal bone augmentation for preventing the re-expansion process and for augmenting the density of the regenerated tissues. To cite this article: Lambert F, Léonard A, Drion P, Sourice S, Layrolle P, Rompen E. Influence of space-filling materials in subantral bone augmentation: blood clot vs. autogenous bone chips vs. bovine hydroxyapatite. Clin. Oral Impl. Res. xx, 2010; 000-000. PMID: 21198906 [PubMed - as supplied by publisher] | | | | | | | | | | | | | | | | | | | | | | | | | Analysis and three-dimensional visualization of collagen in artificial scaffolds using nonlinear microscopy techniques. J Biomed Opt. 2010 November/December;15(6):066011 Authors: Filová E, Burdíková Z, Rampichová M, Bianchini P, Čapek M, Košt'áková E, Amler E, Kubínová L Extracellularly distributed collagen and chondrocytes seeded in gelatine and poly-ɛ-caprolactone scaffolds are visualized by two-photon excitation microscopy (TPEM) and second-harmonic generation (SHG) imaging in both forward and backward nondescanned modes. Joint application of TPEM and SHG imaging in combination with stereological measurements of collagen enables us not only to take high-resolution 3-D images, but also to quantitatively analyze the collagen volume and a spatial arrangement of cell-collagen-scaffold systems, which was previously impossible. This novel approach represents a powerful tool for the analysis of collagen-containing scaffolds with applications in cartilage tissue engineering. PMID: 21198185 [PubMed - as supplied by publisher] | | | | | | | | | | | | | | | | | | | | | | | | | Tissue engineering--the gateway to regenerative medicine. Chimia (Aarau). 2010;64(11):808-12 Authors: Bono E, Mathes SH, Franscini N, Graf-Hausner U Tissue engineering as an emerging biotechnology sector aims at the in vitro regeneration of diseased tissues and promises to profoundly change medical practice, offering the possibility of regenerating tissues and organs instead of just repairing them (regenerative medicine). Improved healing processes and a higher quality of life are the expected results. This article gives an overview of different technologies for regenerative medicine and presents results of our own current applied research and development. A recent project was successfully closed with the development of a natural biomaterial for soft tissue oral defects. The establishment of an in vitro bioreactor system enabled us to simulate the mechanical and biological environment in a healing wound and to investigate the suitability of different implant materials for the oral tissue regeneration. Moreover, focusing the attention on an alternative method for the intervertebral disc (IVD) regeneration, we established a new tissue engineered approach, based on the three-dimensional (3D) culture of autologous human IVD cells into a polyurethane (PU)-fibrin composite. IVD cells were able to proliferate and, thanks to the 3D conditions, to differentiate expressing the typical native tissue markers. The development of an automated platform was the goal of an additional project, to standardize the cell culture technology, increase the bio-safety and reduce the production costs, moving tissue engineering nearer to clinical application. PMID: 21197846 [PubMed - in process] | | | | | | | | | | | | | | | | | | | | | | | | | Interactions between human osteoblasts and prostate cancer cells in a novel 3D in vitro model. Organogenesis. 2010 Jul;6(3):181-8 Authors: Sieh S, Lubik AA, Clements JA, Nelson CC, Hutmacher DW Cell-cell and cell-matrix interactions play a major role in tumor morphogenesis and cancer metastasis. Therefore, it is crucial to create a model with a biomimetic microenvironment that allows such interactions to fully represent the pathophysiology of a disease for an in vitro study. This is achievable by using three-dimensional (3D) models instead of conventional two-dimensional (2D) cultures with the aid of tissue engineering technology. We are now able to better address the complex intercellular interactions underlying prostate cancer (CaP) bone metastasis through such models. In this study, we assessed the interaction of CaP cells and human osteoblasts (hOBs) within a tissue engineered bone (TEB) construct. Consistent with other in vivo studies, our findings show that intercellular and CaP cell-bone matrix interactions lead to elevated levels of matrix metalloproteinases, steroidogenic enzymes and the CaP biomarker, prostate specific antigen (PSA); all associated with CaP metastasis. Hence, it highlights the physiological relevance of this model. We believe that this model will provide new insights for understanding of the previously poorly understood molecular mechanisms of bone metastasis, which will foster further translational studies, and ultimately offer a potential tool for drug screening. PMID: 21197221 [PubMed - in process] | | | | | | | | | | | | | | | | | | | | | | | | | Injectable in situ forming biodegradable chitosan-hyaluronic acid based hydrogels for adipose tissue regeneration. Organogenesis. 2010 Jul;6(3):173-80 Authors: Tan H, Rubin JP, Marra KG An injectable, biodegradable and glucose-responsive hydrogel derived from natural polysaccharide derivatives was synthesized to deliver adipogenic factor of insulin in vitro for adipose tissue engineering. The biodegradable hydrogel based N-succinyl-chitosan (SCS) and aldehyde hyaluronic acid (AHA) with covalently conjugated glucose oxidase and catalase. The gelation is attributed to the Schiff-base reaction between amino and aldehyde groups of SCS and AHA, respectively. The morphologies and compressive modulus of the freeze-dried hydrogels demonstrated that the incorporated insulin and enzymes results in the formation of a tighter network structure in composite hydrogels. The immobilized enzymes triggered conversion of glucose reduces the pH value of the microenvironment, and results in hydrolysis and increasing swelling of the network basing on Schiff-base cross-linking. The pH inside the hydrogel, kept in PBS solution at pH 7.4 and 37°C, linearly dropped from 7.40 to 7.17 during 4 h of initial period, then slowly increased to 7.36 after 24 h. Correspondingly, the swelling ratio increased from 20.8 to 28.6 at 37°C in PBS with 500 mg/dL glucose. In PBS buffer with 500 mg/dL glucose, about 10.8% of insulin was released from the hydrogel after 8 h of incubation while upon observation. The results demonstrated that the adipogenic factor of insulin would be released from this biodegradable hydrogel device into the local microenvironment in a controlled fashion by the swelling of hydrogel network. These preliminary studies indicate that the biodegradable and glucose-responsive hydrogel may have potential uses in adipose tissue engineering applications. PMID: 21197220 [PubMed - in process] | | | | | | | | | | | | | | | | | | | | | | | | | Advances in musculoskeletal tissue engineering: Moving towards therapy. Organogenesis. 2010 Jul;6(3):167-72 Authors: Rossi CA, Pozzobon M, De Coppi P Skeletal muscle can self-repair, but is unable to restore significant tissue loss, as consequence of trauma, congenital defects, tumor ablation or denervation. Intramuscular injection of autologous or allogenic derived myogenic cells (namely satellite cells and myoblasts) did not lead to efficient regeneration because of poor cell retention and survival, as well as immunorejection. In the last decade, tissue engineering looked at overcoming these problems by investigating alternative treatment options, i.e., the suspension of myogenic precursors in temporary matrix, formed by biodegradable and biocompatible materials. This approach allows to engineer custom architectured preconditioned implants, and locally deliver paracrine factors.This article reviews current and potential strategies for the repair of damaged muscle and suggests some innovative approaches for the translation to the clinical setting. PMID: 21197219 [PubMed - in process] | | | | | | | | | | | | | | | | | | | | | | | | | Development, characterization and clinical use of a biodegradable composite scaffold for bone engineering in oro-maxillo-facial surgery. Organogenesis. 2010 Jul;6(3):161-6 Authors: Davies JE, Matta R, Mendes VC, Perri de Carvalho PS We have developed a biodegradable composite scaffold for bone tissue engineering applications with a pore size and interconnecting macroporosity similar to those of human trabecular bone. The scaffold is fabricated by a process of particle leaching and phase inversion from poly(lactideco-glycolide) (PLGA) and two calcium phosphate (CaP) phases both of which are resorbable by osteoclasts; the first a particulate within the polymer structure and the second a thin ubiquitous coating. The 3-5 μm thick osteoconductive surface CaP abrogates the putative foreign body giant cell response to the underlying polymer, while the internal CaP phase provides dimensional stability in an otherwise highly compliant structure. The scaffold may be used as a biomaterial alone, as a carrier for cells or a three-phase drug delivery device. Due to the highly interconnected macroporosity ranging from 81% to 91%, with macropores of 0.8∼1.8 mm, and an ability to wick up blood, the scaffold acts as both a clot-retention device and an osteoconductive support for host bone growth. As a cell delivery vehicle, the scaffold can be first seeded with human mesenchymal cells which can then contribute to bone formation in orthotopic implantation sites, as we show in immune-compromised animal hosts. We have also employed this scaffold in both lithomorph and particulate forms in human patients to maintain alveolar bone height following tooth extraction, and augment alveolar bone height through standard sinus lift approaches. We provide a clinical case report of both of these applications; and we show that the scaffold served to regenerate sufficient bone tissue in the wound site to provide a sound foundation for dental implant placement. At the time of writing, such implants have been in occlusal function for periods of up to 3 years in sites regenerated through the use of the scaffold. PMID: 21197218 [PubMed - in process] | | | | | | | | | | | | | | | | | | | | | | | | | Strategies for organ level tissue engineering. Organogenesis. 2010 Jul;6(3):151-7 Authors: Rustad KC, Sorkin M, Levi B, Longaker MT, Gurtner GC The field of tissue engineering has made considerable strides since it was first described in the late 1980s. The advent and subsequent boom in stem cell biology, emergence of novel technologies for biomaterial development and further understanding of developmental biology have contributed to this accelerated progress. However, continued efforts to translate tissue-engineering strategies into clinical therapies have been hampered by the problems associated with scaling up laboratory methods to produce large, complex tissues. The significant challenges faced by tissue engineers include the production of an intact vasculature within a tissue-engineered construct and recapitulation of the size and complexity of a whole organ. Here we review the basic components necessary for bioengineering organs-biomaterials, cells and bioactive molecules-and discuss various approaches for augmenting these principles to achieve organ level tissue engineering. Ultimately, the successful translation of tissue-engineered constructs into everyday clinical practice will depend upon the ability of the tissue engineer to "scale up" every aspect of the research and development process. PMID: 21197216 [PubMed - in process] | | | | | | | | | | | | | | | | | | | | | | | | | Tissue engineering of bone: an ectopic rat model. Front Biosci (Schol Ed). 2011;3:61-8 Authors: Binderman I, Yaffe A, Zohar R, Benayahu D, Bahar H Tissue engineering is attempting to recreate the complexity of living tissues. In order to test a variety of scaffolds or cells that are constantly being developed, we describe here a model where tissue engineering of bone in a non-osseous environment at subcutaneous thoracic site of DA rats generates. In this model, cell - matix interactions can mimic the normal cascade of bone development into a well organized ossicle like structure including newly formed bone marrow, during 3-4 weeks. Histogenesis of cartilage, bone and bone marrow is closely related to changes in molecular expression of essential early transcriptional regulators of osteoblast differentiation. We tested different organic, anorganic and polymeric scaffolds and their interaction with mesenchymal stem cells present in fresh bone marrow. In another series of experiments we tested mesenchymal populations separated from cultures of calvaria and periosteum for their ability to form bone in the same rat model. It is concluded that this in vivo model is very potent in studying cell-scaffold interactions affecting the temporal and spatial tissue engineering of bone. PMID: 21196357 [PubMed - in process] | | | | | | | | | | | | | | | | | | | | | | | | | Advancements and challenges in dental pulp and dentin tissue regeneration. Front Biosci (Elite Ed). 2011;3:788-800 Authors: Huang GT Hard tissue is difficult to repair especially dental structures. Tooth enamel is incapable of self-repairing whereas dentin and cementum can regenerate with limited capacity. Enamel and dentin are commonly under the attack by caries. Extensive forms of caries destroy enamel and dentin and can lead to dental pulp infection. Entire pulp amputation followed by the pulp space disinfection and filling with an artificial rubber-like material is employed to treat the infection -- commonly known as root canal or endodontic therapy. Regeneration of dentin relies on having vital pulps; however, regeneration of pulp tissue has been difficult as the tissue is encased in dentin without collateral blood supply except from the root apical end. With the advent of modern tissue engineering concept and the discovery of dental stem cells, regeneration of pulp and dentin has been tested. This article will review the recent endeavor on pulp and dentin tissue engineering and regeneration. The prospective outcomes of current advancements and challenges in this line of research are discussed. PMID: 21196351 [PubMed - in process] | | | | | | | | | | | | | | | | | | | | | | | | | Alternatives to heart transplantation: integration of biology with surgery. Front Biosci (Elite Ed). 2011;3:635-47 Authors: Herreros J, Trainini JC, Chachques JC Chronic heart failure is one of the major health care issues in terms of increasing number of patients, rate of hospitalizations and costs. Heart transplantation is the best established therapy for patients with severe heart failure. However, the number of donors limits the activity to 5000 heart transplants performed annually worldwide. This limitation has generated alternative treatments. The increase of the interest in the reversibility of the heart failure and the application of new biological alternatives has generated therapeutic strategies designed to integrate biology and medical technologies in order to act to the biomechanical, the molecular and the neurohormonal mechanisms of heart failure. These treatments include cellular cardiomyoplasty, tissue engineering, surgical left ventricular restoration as well as passive and active mechanical ventricular assistance as destination therapy, bridge to recovery or bridge to transplantation. The integrated development of these approaches could offer hopeful treatments, although there is still much to be learned regarding the optimal use of these strategies. PMID: 21196341 [PubMed - in process] | | | | | | | | | | | | | | | | | | | | | | | | | Isolation and expansion of adipose-derived stem cells for tissue engineering. Front Biosci (Elite Ed). 2011;3:256-63 Authors: Fink T, Rasmussen JG, Lund P, Pilgaard L, Soballe K, Zachar V For treatment of cardiac failure with bone marrow-derived mesenchymal stem cells, several clinical trials are ongoing. However, more attention is gathering on the use of adipose tissue-derived stem cells (ASCs). This paper describes the optimization of isolation and propagation of ASCs for subsequent clinical use. In the isolation step, several enzymes were compared with respect to yield of nucleated cells and precursor cells. Our results showed, that the interdonor variablility was greater than differences between individual enzymes. For propagation of cells, different types of media, sera and serum replacers were evaluated regarding their ability to support cell growth and preserve differentiation potential. Most of serum replacers proved inferior to fetal calf serum. Among the media tested, modified Eagle's media alpha was superior in promoting cell growth while preserving the ability to differentiate. Also, the effect of cell seeding density and hypoxic culture was evaluated. In this study, we show that it is possible to maximize cell yield regardless of donor individual characteristics by simple manipulations of media composition, cell seeding density and gaseous environment. PMID: 21196306 [PubMed - in process] | | | | | | | | | | | | | | | | | | | | | | | | | Crystalline calcium carbonate and hydrogels as microenvironment for stem cells. Front Biosci. 2011;16:458-71 Authors: Astachov L, Nevo Z, Aviv M, Vago R Stem cell development and fate decisions are dictated by the microenvironment in which the stem cell is embedded. Among the advanced goals of tissue engineering is the creation of a microenvironment that will support the maintenance and differentiation of the stem cell - based on embryonic and adult stem cells as potent, cellular sources - for a variety of clinical applications. This review discusses some of the approaches used to create regulatory and instructive microenvironments for the directed differentiation of mesenchymal stem cells (MSCs) using three-dimensional crystalline calcium carbonate biomaterials of marine origin combined with a hydrated gel based on hyaluronan. PMID: 21196181 [PubMed - in process] | | | | | | | | | | | | | | | | | | | | | | | | | Self-assembled composite matrix in a hierarchical 3D scaffold for bone tissue engineering. Acta Biomater. 2010 Dec 30; Authors: Chen M, Le DQ, Baatrup A, Nygaard JV, Hein S, Bjerre L, Kassem M, Zou X, Bünger C It is of high clinical relevance in bone tissue engineering that scaffolds promote a high seeding efficiency of cells capable of osteogenic differentiation, such as human bone marrow-derived mesenchymal stem cells (hMSC). We evaluated the effects of a novel polycaprolactone (PCL) scaffold on hMSC seeding efficiency, proliferation, distribution, and differentiation. Porous PCL meshes prepared by fused deposition modeling (FDM) were embedded in matrix of hyaluronic acid, methylated collagen, and terpolymer via polyelectrolyte complex coacervation. Scaffolds were cultured statically and dynamically in osteogenic stimulation medium for up to 28 days. Compared to naked PCL scaffolds, embedded scaffolds provided a higher cell seeding efficiency (t-test, p<0.05), a more homogenous cell distribution, and more osteogenically differentiated cells, verified by a more pronounced gene expression of the bone markers alkaline phosphatase, osteocalcin, bone sialoprotein I, and bone sialoprotein II. Dynamic culture resulted in higher DNA amounts (day 14 and day 21) and calcium contents (day 21 and day 28), compared to static culture. Dynamic culture and the embedding synergistically enhanced the calcium deposition of hMSC on day 21 and day 28. This in vitro study provides evidence for the effectiveness of hybrid scaffolds made from natural and synthetic polymers on improving cellular seeding efficiency, proliferation, distribution, and osteogenic differentiation. PMID: 21195810 [PubMed - as supplied by publisher] | | | | | | | | | | | | | | | | | | | | | | | | | A sandwich model for engineering cartilage with acellular cartilage sheets and chondrocytes. Biomaterials. 2010 Dec 29; Authors: Gong YY, Xue JX, Zhang WJ, Zhou GD, Liu W, Cao Y Acellular cartilage can provide a native extracellular matrix for cartilage engineering. However, it is difficult for cells to migrate into acellular cartilage because of its non-porous structure. The aim of this study is to establish a sandwich model for engineering cartilage with acellular cartilage sheets and chondrocytes. Cartilage from adult pig ear was cut into a circular cylinder with a diameter of approximately 6 mm and freeze-sectioned at thicknesses of 10 μm and 30 μm. The sheets were then decellularized and lyophilized. Chondrocytes isolated from newborn pig ear were expanded for 2 passages. The acellular sheets and chondrocytes were then stacked layer-by-layer, in a sandwich model, and cultured in dishes. After 4 weeks of cultivation, the constructs were then either maintained in culture for another 12 weeks or implanted subcutaneously in nude mouse. Histological analysis showed that cells were completely removed from cartilage sheets after decellularization. By re-seeding cells and stacking 20 layers of sheets together, a cylinder-shaped cell sheet was achieved. Cartilage-like tissues formed after 4 weeks of culture. Histological analyses showed the formation of cartilage with a typical lacunar structure. Cartilage formation was more efficient with 10 μm-thick sheets than with 30 μm sheets. Mature cartilage was achieved after 12 weeks of implantation, which was demonstrated by histology and confirmed by Safranin O, Toluidine blue and anti-type II collagen antibody staining. Furthermore, we achieved cartilage with a designed shape by pre-shaping the sheets prior to implantation. These results indicate that the sandwich model could be a useful model for engineering cartilage in vitro and in vivo. PMID: 21194746 [PubMed - as supplied by publisher] | | | | | | | | | | | | | | | | | | | | | | | | | In vivo imaging for stem cell therapy: new developments and future challenges. Eur J Nucl Med Mol Imaging. 2011 Jan 4; Authors: Lucignani G, Rodriguez-Porcel M PMID: 21203755 [PubMed - as supplied by publisher] | | | | | | | | | | | | | | | | | | | | | | | | | Adipose-Derived Stem Cells for Wound Healing Applications. Ann Plast Surg. 2010 Dec 30; Authors: Cherubino M, Rubin JP, Miljkovic N, Kelmendi-Doko A, Marra KG Nonhealing wounds remain a significant challenge for plastic surgeons. More than 600,000 people suffer from venous ulcers and 1.5 to 3 million people are being treated for pressure sores every year in the United States. The use of tissue engineering techniques such as stem-cell therapy and gene therapy to improve wound healing is a promising strategy. Adipose tissue represents a source of cells that may be able to enhance wound healing. Adipose-derived stem cells (ASCs) are adult stem cells that are easily harvested and of great interest for plastic surgeons. Specifically, ASCs secrete angiogenic growth factors that can induce tissue regeneration. This review describes innovative research strategies using ASCs therapies for treatment of chronic, nonhealing wounds. PMID: 21200308 [PubMed - as supplied by publisher] | | | | | | | | | | | | | | | | | | | | | | | | | Repair mechanisms of bone marrow mesenchymal stem cells in myocardial infarction. J Cell Mol Med. 2010 Dec 28; Authors: Wen Z, Zheng S, Zhou C, Wang J, Wang T The prognosis of patients with myocardial infarction (MI) and resultant chronic heart failure remains extremely poor despite advances in optimal medical therapy and interventional procedures. Animal experiments and clinical trials using adult stem cell therapy following MI have shown a global improvement of myocardial function. Bone marrow-derived mesenchymal stem cells (MSCs) hold promise for cardiac repair following MI, due to their multi-lineage, self-renewal and proliferation potential. In addition, MSCs can be easily isolated, expanded in culture, and have immunoprivileged properties to the host tissue. Experimental studies and clinical trials have revealed that MSCs not only differentiate into cardiomyocytes and vascular cells, but also secrete amounts of growth factors and cytokines which may mediate endogenous regeneration via activation of resident cardiac stem cells and other stem cells, as well as induce neovascularization, anti-inflammation, anti-apoptosis, anti-remodeling and cardiac contractility in a paracrine manner. It has also been postulated that the anti-arrhythmic and cardiac nerve sprouting potential of MSCs may contribute to their beneficial effects in cardiac repair. Most molecular and cellular mechanisms involved in the MSC-based therapy after MI are still unclear at present. This article reviews the potential repair mechanisms of MSCs in the setting of MI. PMID: 21199333 [PubMed - as supplied by publisher] | | | | | | | | | | | | | | | | | | | | | | | | | Current controversies in prenatal diagnosis 1: is stem cell therapy ready for human fetuses? Prenat Diagn. 2011 Jan 3; Authors: Mummery C, Westgren M, Sermon K PMID: 21197677 [PubMed - as supplied by publisher] | | | | | | | | | | | | | | | | | | | | | | | | | Safety and efficacy of bone marrow-derived autologous CD133+ stem cell therapy. Front Biosci (Elite Ed). 2011;3:506-14 Authors: Adler DS, Lazarus H, Nair R, Goldberg JL, Greco NJ, Lassar T, Laughlin MJ, Das H, Pompili VJ The Phase I clinical study was designed to assess the safety and feasibility of a dose escalating intracoronary infusion of autologous bone marrow (BM)-derived CD133+ stem cell therapy to the patients with chronic total occlusion (CTO) and ischemia. Nine patients were received CD133+ cells into epicardial vessels supplying collateral flow to areas of viable ischemic myocardium in the distribution of the CTO. There were no major adverse cardiac events (MACE), revascularization, re-admission to the hospital secondary to angina, or acute myocardial infarction (AMI) for the 24-month period following cellular infusion. In addition, there were no periprocedural infusion-related complications including malignant arrhythmias, loss of normal coronary blood flow or acute neurologic events. Cardiac enzymes were negative in all patients. There was an improvement in the degree of ischemic myocardium, which was accompanied by a trend towards reduction in anginal symptoms. Intracoronary infusion of autologous CD133+ marrow-derived cells is safe and feasible. Cellular therapy with CD133+ cells to reduce anginal symptoms and to improve ischemia in patients with CTO awaits clinical investigation in Phase II/III trials. PMID: 21196330 [PubMed - in process] | | | | | | | | | | | | | | | | | | | | | | | | | Pulmonary Hypertension in COPD: Pathophysiology and Therapeutic Targets. Curr Drug Targets. 2011 Jan 3; Authors: Zakynthinos E, Daniil Z, Papanikolaou G, Makris D The incidence of mild to moderate pulmonary hypertension (PH) is highly prevalent, reaching to 50% in advanced chronic obstructive pulmonary disease (COPD). However, a subpopulation (1-4% in most studies) with grim prognosis despite moderate airflow limitation, present with "out-of-proportion" severe PH, is arbitrarily defined by a mean PH≥40 mmHg, at rest. The sequence of changes that lead to PH in COPD begins at early disease stages by the impairment of endothelial function, which is associated with impaired release of endothelium-derived vasodilating (nitric oxide, prostacyclin) and vasoconstrictive agents (endothelin-1) and imbalance among them. PH in COPD is caused by vasoconstriction and remodelling of pulmonary arteries, which is characterized by the intimal proliferation of poorly differentiated smooth muscle cells and the deposition of elastic and collagen fibres. Hypoxia, inflammation and toxic effects of cigarette smoke, independently or additively interacting, are confirmed factors leading to PH. To date, long-term supplemental oxygen remains the primary treatment in COPD patients with PH. The administration of new vasodilators (prostanoids, endothelin-1 receptor antagonists and phosphodiesterase-5 inhibitors) dedicated to idiopathic pulmonary arterial hypertension in the disproportionate subgroup of patients with "out-of-proportion" PH may be considered in the setting of clinical trials. The use of these drugs in COPD patients with PH<40 mmHg may worsen gas exchange, and to date, has no proven benefit. Future treatments must target more directly pathogenetic mechanisms. Therefore, novel agents have been proposed and are under active investigation, including 5-HT receptor antagonists, Rho-kinase inhibitors, statins and stem cell therapy. PMID: 21194405 [PubMed - as supplied by publisher] | | | | | | | | | | | | | | | | | | | | | | | | | Complete reprogramming to all-iPS mice. Protein Cell. 2010 Jan;1(1):2-3 Authors: Cheng SY PMID: 21203990 [PubMed - in process] | | | | | | | | | | | | | | | | | | | | | | | | | RNAi screen in Drosophila yields a fat catch of Hedgehog. Protein Cell. 2010 Mar;1(3):205-6 Authors: Cheng SY PMID: 21203965 [PubMed - in process] | | | | | | | | | | | | | | | | | | | | | | | | | Cancer stem cells in glioblastoma-molecular signaling and therapeutic targeting. Protein Cell. 2010 Jul;1(7):638-55 Authors: Huang Z, Cheng L, Guryanova OA, Wu Q, Bao S Glioblastomas (GBMs) are highly lethal primary brain tumors. Despite current therapeutic advances in other solid cancers, the treatment of these malignant gliomas remains essentially palliative. GBMs are extremely resistant to conventional radiation and chemotherapies. We and others have demonstrated that a highly tumorigenic subpopulation of cancer cells called GBM stem cells (GSCs) promotes therapeutic resistance. We also found that GSCs stimulate tumor angiogenesis by expressing elevated levels of VEGF and contribute to tumor growth, which has been translated into a useful therapeutic strategy in the treatment of recurrent or progressive GBMs. Furthermore, stem cell-like cancer cells (cancer stem cells) have been shown to promote metastasis. Although GBMs rarely metastasize beyond the central nervous system, these highly infiltrative cancers often invade into normal brain tissues preventing surgical resection, and GSCs display an aggressive invasive phenotype. These studies suggest that targeting GSCs may effectively reduce tumor recurrence and significantly improve GBM treatment. Recent studies indicate that cancer stem cells share core signaling pathways with normal somatic or embryonic stem cells, but also display critical distinctions that provide important clues into useful therapeutic targets. In this review, we summarize the current understanding and advances in glioma stem cell research, and discuss potential targeting strategies for future development of anti-GSC therapies. PMID: 21203936 [PubMed - in process] | | | | | | | | | | | | | | | | | | | | | | | | | Insulin, longevity, and genetic analysis of metabolism. Protein Cell. 2010 Jul;1(7):605-6 Authors: Cheng SY PMID: 21203930 [PubMed - in process] | | | | | | | | | | | | | | | | | | | | | | | | | Adipose-Derived Stem Cells for Wound Healing Applications. Ann Plast Surg. 2010 Dec 30; Authors: Cherubino M, Rubin JP, Miljkovic N, Kelmendi-Doko A, Marra KG Nonhealing wounds remain a significant challenge for plastic surgeons. More than 600,000 people suffer from venous ulcers and 1.5 to 3 million people are being treated for pressure sores every year in the United States. The use of tissue engineering techniques such as stem-cell therapy and gene therapy to improve wound healing is a promising strategy. Adipose tissue represents a source of cells that may be able to enhance wound healing. Adipose-derived stem cells (ASCs) are adult stem cells that are easily harvested and of great interest for plastic surgeons. Specifically, ASCs secrete angiogenic growth factors that can induce tissue regeneration. This review describes innovative research strategies using ASCs therapies for treatment of chronic, nonhealing wounds. PMID: 21200308 [PubMed - as supplied by publisher] | | | | | | | | | | | | | | | | | | | | | | | | | Kidney Transplant from the Same Donor without Maintenance Immunosuppression after Previous Hematopoietic Stem Cell Transplant. Am J Transplant. 2011 Jan;11(1):156-162 Authors: Fangmann J, Kathrin Al-Ali H, Sack U, Kamprad M, Tautenhahn HM, Faber S, Hauss J, Niederwieser D, Lindner T, Bachmann A In January 2005, an 18-year-old male patient with acute myeloid leukemia (AML) received a haploidentical hematopoietic stem cell transplantation (HSCT) from his father. He developed hemolytic uremic syndrome and end-stage renal disease (ESRD) requiring hemodialysis on day 357 after HSCT. On day 1020 after HSCT, a living kidney donation from the stem cell donor was carried out. The creatinine before kidney transplantation (KT) was ≈450 μmol/L, 268 μmol/L on day 2 after KT, 88 μM on day 38 and 89 μmol/L on day 960 (day 1980 after HSCT). Immunosuppression was gradually discontinued: cortisone on day 28, tacrolimus on day 32 and MMF on day 100 after KT (day 1120 after HSCT). As of June 2010, 66 months after HSCT and 32 months after KT, the patient has had neither rejection episodes nor clinical manifestations of transplantation-related complications. The patient reached 100% hematopoietic donor chimerism prekidney transplant and retained this state postkidney transplant. This unique case is the first report of a successful kidney transplant without immunosuppression after HSCT from the same haploidentical donor. PMID: 21199355 [PubMed - as supplied by publisher] | | | | | | | | | | | | | | | | | | | | | | | | | Plasma biomarker discovery and validation for colorectal cancer by quantitative shotgun mass spectrometry and protein microarray. Cancer Sci. 2010 Dec 3; Authors: Murakoshi Y, Honda K, Sasazuki S, Ono M, Negishi A, Matsubara J, Sakuma T, Kuwabara H, Nakamori S, Sata N, Nagai H, Ioka T, Okusaka T, Kosuge T, Shimahara M, Yasunami Y, Ino Y, Tsuchida A, Aoki T, Tsugane S, Yamada T The development of a new plasma biomarker for early detection would be necessary to improve the overall outcome of colorectal cancer. Here we report the identification and validation of the ninth component of complement (C9) as a novel plasma biomarker for colorectal cancer by cutting-edge proteomic technologies. Plasma proteins were enzymatically digested into a large array of peptides, and the relative quantity of a total of 94 803 peptide peaks was compared between 31 colorectal cancer patients and 59 age/sex-matched healthy controls using 2D image-converted analysis of liquid chromatography and mass spectrometry. The selected biomarker candidates were validated in 345 subjects (115 colorectal cancer patients and 230 age/sex-matched healthy controls) using high-density reverse-phase protein microarrays. Plasma levels of Apo AI and C9 in colorectal cancer patients significantly differed from healthy controls with P values of 7.94 × 10(-4) and 1.43 × 10(-12) (Student's t-test), respectively. In particular, C9 was elevated in patients with colorectal cancer, including those with stage-I and -II diseases (P = 3.01 × 10(-3) and P = 1.13 × 10(-5) , respectively). Although the significance of the present study must be validated in an independent clinical study, the increment of plasma C9 may be applicable to the early detection of colorectal cancer. (Cancer Sci, doi: 10.1111/j.1349-7006.2010.01818.x, 2010). PMID: 21199170 [PubMed - as supplied by publisher] | | | | | | | | | | | | | | | | | | | | | | | | | In vitro mesenchymal stem cell differentiation after mechanical stimulation. Cell Prolif. 2011 Feb;44(1):99-108 Authors: Sarraf CE, Otto WR, Eastwood M Objectives: Mesenchymal stem cells (MSC) are multipotent cells capable of differentiating into adipocytic, chondrocytic and osteocytic lineages on suitable stimulation. We have hypothesized that mechanical loading may influence MSC differentiation and alter their phenotype accordingly. Materials and methods: Mouse bone marrow-derived MSC were established in vitro by differential adherence to plastic culture plates and grown in low glucose medium with 10% foetal calf serum and growth factors. Cells grew out and were subcultured up to 20 times. Differentiation protocols were followed for several cell lineages. Clones with trilineage potential were seeded in type I collagen gels and incubated in a tensioning force bioreactor and real-time cell-derived forces were recorded. Gels were fixed and sectioned for light and electron microscopy. Results: Cell monolayers of parent and cloned mouse bone marrow-derived MSC differentiated into adipocytes, osteocytes and chondrocytes, but not into cardiomyocytes, myotubes or neuronal cells. When cast into type I collagen gels and placed in tensioning bioreactors, MSC differentiated into fibroblast-like cells typical of tissue stroma, and upregulated α-smooth muscle actin, but rarely upregulated desmin. Electron microscopy showed collagen and elastin fibre synthesis into the matrix. Conclusions: These experiments confirmed that MSC cell fate choice depends on minute, cell-derived forces. Applied force could assist in commercial manufacture of cultured bio-engineered prostheses for regenerative medicine as it mimics tissue stresses and constitutes a good model for development of tissue substitutes. PMID: 21199014 [PubMed - in process] | | | | | | | | | | | | | | | | | | | | | | | | | Adipose-derived stem cells for clinical applications: a review. Cell Prolif. 2011 Feb;44(1):86-98 Authors: Wilson A, Butler PE, Seifalian AM The use of stem cells derived from adipose tissue as an autologous and self-replenishing source for a variety of differentiated cell phenotypes, provides a great deal of promise for reconstructive surgery. In this article, we review available literature encompassing methods of extraction of pluripotent adipose stem cells (ASCs) from lipoaspirate locations, their storage, options for culture, growth and differentiation, cryopreservation and its effect on stem cell survival and proliferation, and new technologies involving biomaterials and scaffolds. We will conclude by assessing potential avenues for developing this incredibly promising field. PMID: 21199013 [PubMed - in process] | | | | | | | | | | | | | | | | | | | | | | | | | Fibrin acts as biomimetic niche inducing both differentiation and stem cell marker expression of early human endothelial progenitor cells. Cell Prolif. 2011 Feb;44(1):33-48 Authors: Barsotti MC, Magera A, Armani C, Chiellini F, Felice F, Dinucci D, Piras AM, Minnocci A, Solaro R, Soldani G, Balbarini A, Di Stefano R Objectives: Transplantation of endothelial progenitor cells (EPCs) is a promising approach for revascularization of tissue. We have used a natural and biocompatible biopolymer, fibrin, to induce cell population growth, differentiation and functional activity of EPCs. Materials and methods: Peripheral blood mononuclear cells were cultured for 1 week to obtain early EPCs. Fibrin was characterized for stiffness and capability to sustain cell population expansion at different fibrinogen-thrombin ratios. Viability, differentiation and angiogenic properties of EPCs were evaluated and compared to those of EPCs grown on fibronectin. Results: Fibrin had a nanometric fibrous structure forming a porous network. Fibrinogen concentration significantly influenced fibrin stiffness and cell growth: 9 mg/ml fibrinogen and 25 U/ml thrombin was the best ratio for enhanced cell viability. Moreover, cell viability was significantly higher on fibrin compared to being on fibronectin. Even though no significant difference was observed in expression of endothelial markers, culture on fibrin elicited marked induction of stem cell markers OCT 3/4 and NANOG. In vitro angiogenesis assay on Matrigel showed that EPCs grown on fibrin retain angiogenetic capability as EPCs grown on fibronectin, but significantly better release of cytokines involved in cell recruitment was produced by EPC grown on fibrin. Conclusion: Fibrin is a suitable matrix for EPC growth, differentiation and angiogenesis capability, suggesting that fibrin gel may be very useful for regenerative medicine. PMID: 21199008 [PubMed - in process] | | | | | | | | | | | | | | | | | | | | | | | | | Expression of Pluripotency Genes in Buffalo (Bubalus bubalis) Amniotic Fluid Cells. Reprod Domest Anim. 2010 Dec 30; Authors: Yadav P, Mann A, Singh V, Yashveer S, Sharma R, Singh I Recent findings suggest that mammalian amniotic fluid (AF) is a source of multipotent stem cells (SCs), which can be used in regenerative medicine and assisted reproduction. We report the isolation, culture and characterization of amniotic fluid-derived cells from pregnant water buffalo uterus. These undifferentiated AF cells expanded without feeder layer over a period of 100 days up to passages 20 and the expression of alkaline phosphatase (AP), Oct-4, Nanog and Sox-2, GAPDH and β-actin could be detected by RT-PCR. The cells exhibited uniform morphology and normal chromosome number. The up-regulation or down-regulation of transcription factors of each gene varied with passage number. We conclude that putative bubaline AF cells can be cultured and maintained in vitro for a prolonged period and offer a potential source of multipotent cells for applications including assisted reproduction in buffalo. PMID: 21198969 [PubMed - as supplied by publisher] | | | | | | | | | | | | | | | | | | | | | | | | | Dendritic trafficking of BDNF mRNA: regulation by translin-dependent and -independent mechanisms. J Neurochem. 2010 Dec 27; Authors: Wu Y, Williamson R, Li Z, Vicario A, Xu J, Kasai M, Chern Y, Tongiorgi E, Baraban J Dendritic trafficking and translation of BDNF transcripts play a key role in mediating synaptic plasticity. Recently, we demonstrated that siRNA-mediated knockdown of translin, an RNA binding protein, impairs KCl-induced dendritic trafficking of BDNF mRNA in cultured hippocampal neurons. We have now assessed whether translin deletion impairs dendritic trafficking of BDNF mRNA in hippocampal neurons in vivo. We have found that translin and its partner protein, trax, undergo dendritic translocation in response to treatment with pilocarpine, a pro-convulsant muscarinic agonist that increases dendritic trafficking of BDNF mRNA in hippocampal neurons. In translin knockout mice, the basal level of dendritic BDNF mRNA is decreased in CA1 pyramidal neurons. However, translin deletion does not block pilocarpine's ability to increase dendritic trafficking of BDNF mRNA indicating that the requirement for translin in this process varies with the stimulus employed to drive it. Consistent with this inference, we found that dendritic trafficking of BDNF mRNA induced by bath application of recombinant BDNF in cultured hippocampal neurons, is not blocked by siRNA-mediated knockdown of translin. Taken together, these in vivo and in vitro findings indicate that dendritic trafficking of BDNF mRNA can be mediated by both translin-dependent and -independent mechanisms. PMID: 21198640 [PubMed - as supplied by publisher] | | | | | | | | | | | | | | | | | | | | | | | | | Human mesenchymal stromal cells preserve their stem features better when cultured in the Dulbecco's modified Eagle medium. Cytotherapy. 2011 Jan 3; Authors: Pieri L, Urbani S, Mazzanti B, Pozzo SD, Santosuosso M, Saccardi R, Bosi A, Faussone-Pellegrini MS, Vannucchi MG Abstract Background aims. The human mesenchymal stromal cell (hMSC), a type of adult stem cell with a fibroblast-like appearance, has the potential to differentiate along the mesenchymal lineage and also along other cell lineages. These abilities make hMSC a promising candidate for use in regenerative medicine. As the hMSC represents a very rare population in vivo, in vitro expansion is necessary for any clinical use. hMSC characterization is commonly carried out through the expression of specific markers and by the capability of differentiating toward at least adipo-, osteo- and chondrocytic lineages. Commitment processes also result in significant changes in the ultrastructure in order to acquire new functional abilities; however, few studies have dealt with the ultrastructural characteristics of hMSC according to the time of incubation and type of media. Methods. The immunophenotype, functional characteristics and ultrastructural features of bone marrow (BM) hMSC cultured in two different media were investigated. The media chosen were Iscove's modified Dulbecco's medium (IMDM) and the Dulbecco's modified Eagle medium (DMEM). The latter has been recommended recently by two international transplantation and cytotherapy societies, the International Society of Cellular Therapy (ISCT) and European Group for Blood and Bone Marrow Transplantation (EBMT), for hMSC expansion for clinical applications. Results and Conclusions. The present results indicate that culture conditions greatly influence hMSC ultrastructural features, proliferation, growth and differentiation. In particular, our findings demonstrate that DMEM preserves the hMSC stem features better. Furthermore, the results obtained in IMDM suggest that a small size does not always correlate with conditions of cell immaturity and a greater proliferative potential. PMID: 21198336 [PubMed - as supplied by publisher] | | | | | | | | | | | | | | | | | | | | | | | | | Immunohistochemical evaluation of the heat shock response to nonablative fractional resurfacing. J Biomed Opt. 2010 Nov-Dec;15(6):068002 Authors: Hantash BM, Bedi VP, Struck SK, Chan KF Despite the emergence of nonablative fractional resurfacing (NFR) as a new therapeutic modality for skin photoaging, little is known about the molecular events that underlie the heat shock response to different treatment parameters. Human subjects are treated with a scanned 1550-nm fractional laser at pulse energies spanning 6 to 40 mJ and a 140-μm spot size. The heat shock response is assessed immunohistochemically immediately through 7 days posttreatment. At the immediately posttreatment time point, we observe subepidermal clefting in most sections. The basal epidermis and dermal zones of sparing are both found to express HSP47, but not HSP72. By day 1, expression of HSP72 is detected throughout the epidermis, while that of HSP47 remains restricted to the basal layer. Both proteins are detected surrounding the dermal portion of the microscopic treatment zone (MTZ). This pattern of expression persists through day 7 post-NFR, although neither protein is found within the MTZ. Immediately posttreatment, the mean collagen denaturation zone width is 50 μm at 6 mJ, increasing to 202 μm at 40 mJ. The zone of cell death exceeds the denaturation zone by 19 to 55% over this pulse energy range. The two zones converge by day 7 posttreatment. PMID: 21198215 [PubMed - in process] | | | | | | | | | | | | | | | | | | | | | | | | | Adipose-Derived Stem Cells for Wound Healing Applications. Ann Plast Surg. 2010 Dec 30; Authors: Cherubino M, Rubin JP, Miljkovic N, Kelmendi-Doko A, Marra KG Nonhealing wounds remain a significant challenge for plastic surgeons. More than 600,000 people suffer from venous ulcers and 1.5 to 3 million people are being treated for pressure sores every year in the United States. The use of tissue engineering techniques such as stem-cell therapy and gene therapy to improve wound healing is a promising strategy. Adipose tissue represents a source of cells that may be able to enhance wound healing. Adipose-derived stem cells (ASCs) are adult stem cells that are easily harvested and of great interest for plastic surgeons. Specifically, ASCs secrete angiogenic growth factors that can induce tissue regeneration. This review describes innovative research strategies using ASCs therapies for treatment of chronic, nonhealing wounds. PMID: 21200308 [PubMed - as supplied by publisher] | | | | | | | | | | | | | | | | | | | | | | | | | Adipose-derived stem cells for clinical applications: a review. Cell Prolif. 2011 Feb;44(1):86-98 Authors: Wilson A, Butler PE, Seifalian AM The use of stem cells derived from adipose tissue as an autologous and self-replenishing source for a variety of differentiated cell phenotypes, provides a great deal of promise for reconstructive surgery. In this article, we review available literature encompassing methods of extraction of pluripotent adipose stem cells (ASCs) from lipoaspirate locations, their storage, options for culture, growth and differentiation, cryopreservation and its effect on stem cell survival and proliferation, and new technologies involving biomaterials and scaffolds. We will conclude by assessing potential avenues for developing this incredibly promising field. PMID: 21199013 [PubMed - in process] | | | | | | | | | | | | | | | | | | | | | | | | | Use of animal protein-free products for passaging adherent human adipose-derived stromal/stem cells. Cytotherapy. 2011 Jan 3; Authors: Carvalho PP, Wu X, Yu G, Dietrich M, Dias IR, Gomes ME, Reis RL, Gimble JM Abstract Adherent adipose-derived stromal/stem cells (ASC) have been used in pre-clinical regenerative medical studies applied to a broad range of tissues with an ultimate goal of translating these findings to clinical safety and efficacy testing; however, many protocols passage the cells using porcine-derived trypsin. We have compared porcine trypsin with animal protein-free products from recombinant bacteria (TrypLE Express; Invitrogene) and corn (TrypZean; Sigma) based on cell yield, viability and immunophenotype. ASC harvested with each trypsin product were comparable. PMID: 21198335 [PubMed - as supplied by publisher] | | | | | | | | | | | | | | | | | | | | | | | | | Human cardiomyogenesis and the need for systems biology analysis. Wiley Interdiscip Rev Syst Biol Med. 2010 Dec 31; Authors: Adam Young D, Dequach JA, Christman KL Cardiovascular disease remains the leading cause of death in the Western world and myocardial infarction is one of the primary facets of this disease. The limited natural self-renewal of cardiac muscle following injury and restricted supply of heart transplants has encouraged researchers to investigate other means to stimulate regeneration of damaged myocardium. The plasticity of stem cells toward multiple lineages offers the potential to repair the heart following injury. Embryonic stem cells have been extensively studied for their ability to differentiate into early cardiomyocytes, however, the pathway has only been partially defined and inadequate efficiency limits their clinical applicability. Some studies have shown cardiomyogenesis from adult mesenchymal stem cells, from both bone marrow and adipose tissue, but their differentiation pathway remains poorly detailed and these results remain controversial. Despite promising results using stem cells in animal models of cardiac injury, the driving mechanisms behind their differentiation down a cardiomyogenic pathway have yet to be determined. Currently, there is a paucity of information regarding cardiomyogenesis on the systemic level. Stem cell differentiation results from multiple signaling parameters operating in a tightly regulated spatiotemporal pattern. Investigating this phenomenon from a systems biology perspective could unveil the abstruse mechanisms controlling cardiomyogenesis that would otherwise require extensive in vitro testing. WIREs Syst Biol Med 2011 DOI: 10.1002/wsbm.141For further resources related to this article, please visit the WIREs website. PMID: 21197666 [PubMed - as supplied by publisher] | | | | | | | | | | | | | | | | | | | | | | | | | Adipose tissue as a stem cell source for musculoskeletal regeneration. Front Biosci (Schol Ed). 2011;3:69-81 Authors: Gimble JM, Grayson W, Guilak F, Lopez MJ, Vunjak-Novakovic G Adipose tissue is an abundant, easily accessible, and reproducible cell source for musculo-skeletal regenerative medicine applications. Initial derivation steps yield a heterogeneous population of cells of stromal vascular fraction (SVF) cells. Subsequent adherent selection of the SVF results in a relatively homogeneous population of adipose-derived stromal/stem cells (ASCs) capable of adipogenic, chondrogenic, myogenic, and osteogenic differentiation in vitro on scaffolds in bioreactors and in vivo in pre-clinical animal models. Unlike hematopoietic cells, ASCs do not elicit a robust lymphocyte reaction and instead release immunosuppressive factors, such as prostaglandin E2. These immunomodulatory features suggest that allogeneic and autologous ASCs will engraft successfully for tissue regeneration purposes. The differentiation and expansion potential of ASCs can be modified by growth factors, bio-inductive scaffolds, and bioreactors providing environmental control and biophysical stimulation. Gene therapy approaches using lentiviral transduction can be used to direct differentiation of ASCs to particular lineages. We discuss the utility of ASCs for musculo-skeletal tissue repair and some of the technologies that can be implemented to unlock the full regenerative potential of these highly valuable cells. PMID: 21196358 [PubMed - in process] | | | | | | | | | | | | | | | | | | | | | | | | | Isolation and expansion of adipose-derived stem cells for tissue engineering. Front Biosci (Elite Ed). 2011;3:256-63 Authors: Fink T, Rasmussen JG, Lund P, Pilgaard L, Soballe K, Zachar V For treatment of cardiac failure with bone marrow-derived mesenchymal stem cells, several clinical trials are ongoing. However, more attention is gathering on the use of adipose tissue-derived stem cells (ASCs). This paper describes the optimization of isolation and propagation of ASCs for subsequent clinical use. In the isolation step, several enzymes were compared with respect to yield of nucleated cells and precursor cells. Our results showed, that the interdonor variablility was greater than differences between individual enzymes. For propagation of cells, different types of media, sera and serum replacers were evaluated regarding their ability to support cell growth and preserve differentiation potential. Most of serum replacers proved inferior to fetal calf serum. Among the media tested, modified Eagle's media alpha was superior in promoting cell growth while preserving the ability to differentiate. Also, the effect of cell seeding density and hypoxic culture was evaluated. In this study, we show that it is possible to maximize cell yield regardless of donor individual characteristics by simple manipulations of media composition, cell seeding density and gaseous environment. PMID: 21196306 [PubMed - in process] | | | | | | | | | | | | | | | | | | | | | | | | | Comparison of equine bone marrow-, umbilical cord matrix and amniotic fluid-derived progenitor cells. Vet Res Commun. 2010 Dec 31; Authors: Lovati AB, Corradetti B, Lange Consiglio A, Recordati C, Bonacina E, Bizzaro D, Cremonesi F The aim of the study was to compare in vitro the stemness features of horse progenitor cells derived from bone marrow (BM-MSCs), amniotic fluid (AF-MSCs) and umbilical cord matrix (EUC-MSCs). It has been suggested that there may be a stem cell population within both umbilical cord matrix and amniotic fluid. However, little knowledge exists about the characteristics of these progenitor cells within these sources in the equine species. This study wanted to investigate an alternative and non-invasive stem cell source for the equine tissue engineering and to learn more about the properties of these cells for future cell banking. Bone marrow, umbilical cord and amniotic fluid samples were harvested from different horses. Cells were analyzed for proliferation, immunocytochemical, stem cell gene expression and multilineage plasticity. BM- and AF-MSCs took similar time to reach confluence and showed comparable plating efficiency. All cell lines expressed identical stem cell markers and capability to differentiate towards osteogenic lineage. Almost all cell lines differentiated into the adipogenic lineage as demonstrated by cytochemical staining, even if no adipose gene expression was detectable for AF-MSCs. AF- and EUC-MSCs showed a limited chondrogenic differentiation compared with BM-MSCs as demonstrated by histological and biochemical analyses. These findings suggest that AF-MSCs appeared to be a readily obtainable and highly proliferative cell line from an uninvasive source that may represent a good model system for stem cell biology. More studies are needed to investigate their multilineage potential. EUC-MSCs need to be further investigated regarding their particular behavior in vitro represented by spheroid formation. PMID: 21193959 [PubMed - as supplied by publisher] | | | | | | | | | |  | |  | |  |
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