|  |  |  | | | | | TERMSC | | | | | | | | | | | | | | | | | | | Compare the effects of chondrogenesis by culture of human mesenchymal stem cells with various type of the chondroitin sulfate C. J Biosci Bioeng. 2010 Oct 27; Authors: Chen WC, Yao CL, Chu IM, Wei YH Chondroitin sulfate C (CSC) is a kind of glycosaminoglycans (GAGs) with molecular weights of 10,000 to 50,000Da and a high charge density. GAGs are major components in extracellular matrix (ECM), which play important role in the regulation of cell proliferation, migration, and differentiation. In this study, we studied the effects of chondroitin sulfate C (CSC) on the differentiation of human mesenchymal stem cells (MSCs) toward the chondrocyte lineage. The MSCs were either cultured on type II collagen (COL II) scaffolds with high molecular weight CSC addition in the medium (free CSC) or with free oligosaccharide CSC. Special attention was given to the effects of MSCs cultured on CSC cross-linked type II scaffolds (cross-linked CSC). According to the analysis of histology stain, gene expression, and ECM secretion, our results showed that MSCs cultured with free CSC, free oligosaccharides CSC, and on the cross-linked CSC scaffolds all would be induced into chondrocytes. Moreover, free oligosaccharide CSC present in the microenvironment could significantly up-regulate MSC chondrogenesis gene expression and stimulate cartilage ECM accumulation more than free CSC with high molecular weight after 3-week induction. Importantly, cross-linked CSC had the most excellent effects on the MSC chondrogenesis. Thus, we believed that cross-linked CSC in the scaffold would play the similar roles with free oligosaccharide CSC in the medium. Cross-linked CSC would be a potential candidate for cartilage repair in the cell therapy and tissue engineering. PMID: 21035392 [PubMed - as supplied by publisher] | | | | | | | | | | | | | | | | | | | | | | | | | Bone Nodules on Chitosan-Polygalacturonic Acid-Hydroxyapatite Nanocomposite Films Mimic Hierarchy of Natural Bone. Acta Biomater. 2010 Oct 26; Authors: Khanna R, Katti KS, Katti DR The ultimate goal of bone tissue engineering is to develop bony tissues on tissue engineered constructs that mimic the native bone. Nanoscale characterization of in vitro generated bony tissues on engineered scaffolds is essential, for understanding both the physical and mechanical characteristics of the engineered bone. Bone nodule formation, a typical early indicator of bone formation was observed on chitosan-polygalacturonic acid-hydroxyapatite (Chi-PgA-HAP) nanocomposite films without the use of differentiating media. Thus, the Chi-PgA-HAP substrates designed, are osteoinductive, and provide an appropriate microenvironment for cell organization and tissue regeneration. Imaging using atomic force microscopy revealed several levels of hierarchical structures of bone in the bone nodules, consisting of mineralized collagen fibers, fibrils and mineral deposits in extrafibrillar spaces. Nanoscale elastic properties of collagen and mineral crystals were found to be in close agreement with experimental and simulations results on natural bone reported in literature. Fourier transform infrared spectroscopy experiments indicate the presence of collagen and biological apatite in bone nodules exhibiting the characteristics of newly precipitated, immature bone. Collectively, our structural, chemical, and mechanical analyses support the conclusion that synthetic bone nodule mimics the hierarchy of natural bone. PMID: 21034863 [PubMed - as supplied by publisher] | | | | | | | | | | | | | | | | | | | | | | | | | Nanomechanics to drive stem cells in injured tissues: insights from current research and future perspectives. Stem Cells Dev. 2010 Oct 29; Authors: Lionetti V, Cecchini M, Ventura C Stem cells reside within tissue, ensuring its natural ability to repair an injury. They are involved in the natural repair of damaged tissue, which encompasses a complex process requiring the modulation of cell survival, extracellular matrix turnover, angiogenesis as well as reverse remodelling. To date, the real reparative potential of each tissue is underestimated and non-committal. The assessment of the biophysical properties of the extracellular environment is an innovative approach to better understand mechanisms underlying stem cell function, and consequently to develop safe and effective therapeutic strategies replacing the loss of tissue. Recent studies have focused on the role played by biomechanical signals that drive stem cell death, differentiation and paracrinicity in a genetic and/or an epigenetic manner. Mechanical stimuli acting on the shape can influence the biochemistry and gene expression of resident stem cells and, therefore, the magnitude of biological responses that promote the healing of injured tissue. Nanotechnologies have proven to be a revolutionary tool capable of dissecting the cellular mechanosensing apparatus, allowing the intercellular cross-talk to be decoded and enabling the reparative potential of tissue to be enhanced without manipulation of stem cells. This review highlights the most relevant findings of stem cell mechanobiology and presents a fascinating perspective in regenerative medicine. PMID: 21034226 [PubMed - as supplied by publisher] | | | | | | | | | | | | | | | | | | | | | | | | | Nonlinear model for viscoelastic behavior of achilles tendon. J Biomech Eng. 2010 Nov;132(11):111002 Authors: Kahn CJ, Wang X, Rahouadj R Although the mechanical properties of ligament and tendon are well documented in research literature, very few unified mechanical formulations can describe a wide range of different loadings. The aim of this study was to propose a new model, which can describe tendon responses to various solicitations such as cycles of loading, unloading, and reloading or successive relaxations at different strain levels. In this work, experiments with cycles of loading and reloading at increasing strain level and sequences of relaxation were performed on white New Zealand rabbit Achilles tendons. We presented a local formulation of thermodynamic evolution outside equilibrium at a representative element volume scale to describe the tendon's macroscopic behavior based on the notion of relaxed stress. It was shown that the model corresponds quite well to the experimental data. This work concludes with the complexity of tendons' mechanical properties due to various microphysical mechanisms of deformation involved in loading such as the recruitment of collagen fibers, the rearrangement of the microstructure (i.e., collagens type I and III, proteoglycans, and water), and the evolution of relaxed stress linked to these mechanisms. PMID: 21034143 [PubMed - in process] | | | | | | | | | | | | | | | | | | | | | | | | | Modeling material-degradation-induced elastic property of tissue engineering scaffolds. J Biomech Eng. 2010 Nov;132(11):111001 Authors: Bawolin NK, Li MG, Chen XB, Zhang WJ The mechanical properties of tissue engineering scaffolds play a critical role in the success of repairing damaged tissues/organs. Determining the mechanical properties has proven to be a challenging task as these properties are not constant but depend upon time as the scaffold degrades. In this study, the modeling of the time-dependent mechanical properties of a scaffold is performed based on the concept of finite element model updating. This modeling approach contains three steps: (1) development of a finite element model for the effective mechanical properties of the scaffold, (2) parametrizing the finite element model by selecting parameters associated with the scaffold microstructure and/or material properties, which vary with scaffold degradation, and (3) identifying selected parameters as functions of time based on measurements from the tests on the scaffold mechanical properties as they degrade. To validate the developed model, scaffolds were made from the biocompatible polymer polycaprolactone (PCL) mixed with hydroxylapatite (HA) nanoparticles and their mechanical properties were examined in terms of the Young modulus. Based on the bulk degradation exhibited by the PCL/HA scaffold, the molecular weight was selected for model updating. With the identified molecular weight, the finite element model developed was effective for predicting the time-dependent mechanical properties of PCL/HA scaffolds during degradation. PMID: 21034142 [PubMed - in process] | | | | | | | | | | | | | | | | | | | | | | | | | Combined Influence of Substrate Stiffness and Surface Topography on the Antiadhesive Properties of Acr-sP(EO-stat-PO) Hydrogels. Biomacromolecules. 2010 Oct 29; Authors: Schulte VA, Diez M, Hu Y, Möller M, Lensen MC Biomaterials that prevent nonspecific protein adsorption and cell adhesion are of high relevance for diverse applications in tissue engineering and diagnostics. One of the most widely applied materials for this purpose is Poly(ethylene glycol) (PEG). We have investigated how micrometer line topography and substrate elasticity act upon the antiadhesive properties of PEG-based hydrogels. In our studies we apply bulk hydrogel cross-linked from star-shaped poly(ethylene oxide-stat-propylene oxide) macromonomers. Substrate surfaces were topographically patterned via replica molding. Additionally, the mechanical properties were altered by variations in the cross-linking density. Surface patterns with dimensions in the range of the cells' own size, namely 10 μm wide grooves, induced significant cell adhesion and spreading on the Acr-sP(EO-stat-PO) hydrogels. In contrast, there was only little adhesion to smaller and larger pattern sizes and no adhesion at all on the smooth substrates, regardless the rigidity of the gel. The effect of varied substrate stiffness on cell behavior was only manifest in combination with topography. Softer substrates with line patterns lead to significantly higher cell adhesion and spreading than stiff substrates. We conclude that the physical and mechanical surface characteristics can eliminate the nonadhesive properties of PEG-based hydrogels to a large extent. This has to be taken into account when designing surfaces for biomedical application such as scaffolds for tissue engineering which rely on the inertness of PEG. PMID: 21033738 [PubMed - as supplied by publisher] | | | | | | | | | | | | | | | | | | | | | | | | | [In vitro and in vivo study of chondrogenesis on the hybrid scaffold from fibrin modified PLGA and adipose-derived stem cells]. Xi Bao Yu Fen Zi Mian Yi Xue Za Zhi. 2010 Aug;26(8):758-60 Authors: Wang J, Zhou Q, Deng LF, Hu YY, Wei YY AIM: To investigated the effect of the presence of fibrin in the PLGA scaffold on the differentiation of adipose-derived stem cell (ASCs) into chondrocytes in the chondrogenic media. METHODS: ASCs were prepared by colagenase I digestion of fat from rabbits. The PLGA scaffolds were prepared by LDM technology. The hybrid scaffold was fabricated by a freeze-drying method. Isolated ASCs were cultured in the PLGA without and with fibrin up to 14 days in specific chondrogenic medium. The surface property of the scaffold was observed by SEM. Cell attachment was evaluated, and glycoaminoglycans (GAGs) content was tested by biochemical method. RESULT: When ASCs were seeded within fibrin modified PLGA scaffold in vitro, enhanced cellular attachment and differentiation were observed compared to unmodified PLGA scaffold. The study from articular cartilage defect repaired showed that the group from the autologous ASCs seeded on fibrin-PLGA scaffold had better chondrocyte morphology, tissue integration, continuous subchondral bone, and much thicker newly formed cartilage layer as compared with other groups. CONCLUSION: Such modification of PLGA may ultimately enhance the efficacy of tissue engineered scaffolds for cartilage tissue engineering using ASCs. PMID: 21032949 [PubMed - in process] | | | | | | | | | | | | | | | | | | | | | | | | | Matrix-induced autologous chondrocyte implantation of talus articular defects. Foot Ankle Int. 2010 Sep;31(9):747-53 Authors: Giza E, Sullivan M, Ocel D, Lundeen G, Mitchell ME, Veris L, Walton J BACKGROUND: Osteochondral injury of the talus can be challenging to treat because the damaged articular cartilage has a poor intrinsic reparative capability. Autologous Chondrocyte Implantation has become an effective means for treating persistent cartilage lesions that fail to respond to routine ankle arthroscopy. The purpose of this study was to assess the results of Matrix-induced autologous chondrocyte implantation (MACI) for the treatment of osteochondral defects of the talar dome using a technique which does not require an osteotomy of the tibia or fibula. MATERIALS AND METHODS: A prospective investigation of MACI was performed on ten patients with full-thickness lesions of the talus. The patients had a documented talus lesion on MRI, failure of conservative treatment and arthroscopic debridement/curettage, persistent ankle pain and swelling, the absence of tibiotalar arthritis and a stable ankle. Five males and five females, with an average of 1.7 previous procedures prior to Matrix-induced autologous implantation, were included in this study. All patients were available for followup at 1 and 2 years. Lesions were graded during the harvesting procedure using the Cheng-Ferkel grading system, the Outerbridge classification, and the International Cartilage Repair Society system. Clinical and functional evaluation was done preoperatively, and at 1 and 2 years postoperatively using the AOFAS hindfoot evaluation and the SF-36 Health Survey. RESULTS: Preoperative AOFAS hindfoot scores were 61.2 (range, 42 to 76) which improved 1 year postoperatively to 74.7 (range, 46 to 87) (p < 0.05) and 2 years postoperatively to 73.3 (range, 42 to 90) (p = 0.151). At both 1 and 2 years postoperatively, the results of the SF36 evaluation demonstrated a significant improvement in the Physical Functioning (p = 0.002) and Bodily Pain (p < 0.001) components. Subjectively, all ten patients believed this procedure helped them. CONCLUSION: The results of this study suggest that MACI may be an effective way to treat full-thickness lesions of the talus using harvested chondrocytes from the talus without malleolar osteotomy. We recommend it for patients who do not respond to initial curettage and microfracture. PMID: 20880476 [PubMed - indexed for MEDLINE] | | | | | | | | | | | | | | | | | | | | | | | | | Defective adult oligodendrocyte and Schwann cell development, pigment pattern, and craniofacial morphology in puma mutant zebrafish having an alpha tubulin mutation. Dev Biol. 2010 Oct 15;346(2):296-309 Authors: Larson TA, Gordon TN, Lau HE, Parichy DM The processes of myelination remain incompletely understood but are of profound biomedical importance owing to the several dysmyelinating and demyelinating disorders known in humans. Here, we analyze the zebrafish puma mutant, isolated originally for pigment pattern defects limited to the adult stage. We show that puma mutants also have late-arising defects in Schwann cells of the peripheral nervous system, locomotor abnormalities, and sex-biased defects in adult craniofacial morphology. Using methods of positional cloning, we identify a critical genetic interval harboring two alpha tubulin loci, and we identify a chemically induced missense mutation in one of these, tubulin alpha 8-like 3a (tuba8l3a). We demonstrate tuba8l3a expression in the central nervous system (CNS), leading us to search for defects in the development of oligodendrocytes, the myelinating cells of the CNS. We find gross reductions in CNS myelin and oligodendrocyte numbers in adult puma mutants, and these deficits are apparent already during the larval-to-adult transformation. By contrast, analyses of embryos and early larvae reveal a normal complement of oligodendrocytes that nevertheless fail to localize normal amounts of myelin basic protein (mbp) mRNA in cellular processes, and fail to organize these processes as in the wild-type. This study identifies the puma mutant as a valuable model for studying microtubule-dependent events of myelination, as well as strategies for remyelination in the adult. PMID: 20692250 [PubMed - indexed for MEDLINE] | | | | | | | | | | | | | | | | | | | | | | | | | iPS cells--alternative pluripotent cells to embryo stem cells. Sci China Life Sci. 2010 Jan;53(1):154-6 Authors: Pei X PMID: 20596969 [PubMed - indexed for MEDLINE] | | | | | | | | | | | | | | | | | | | | | | | | | Naturally occurring IgM anti-leukocyte autoantibodies inhibit T-cell activation and chemotaxis. J Clin Immunol. 2010 May;30 Suppl 1:S31-6 Authors: Lobo PI, Schlegal KH, Vengal J, Okusa MD, Pei H INTRODUCTION: Naturally occurring IgM antileukocyte autoantibodies (IgM-ALA) are present from birth and increase during inflammatory processes of diverse etiologies. The clinical observation demonstrating a significant correlation (P < 01) between lack of acute rejections and presence of high levels of IgM-ALA in recipients of kidney allografts prompted us to study if IgM-ALA alters T-cell function and leukocyte chemotaxis. METHODS: In-vitro functional assays were performed using leucocytes isolated from human peripheral blood. In-vivo studies were performed in C57BL6 mice. RESULT: Human studies revealed that IgM-ALA consist of several different IgM, each with specificities for a different leukocyte receptor, e.g., CD3, CD4, CCR5, and CXCR4. We show that IgM inhibits T-cell activation, proliferation, and chemotaxis. Data on in vivo murine models of ischemia-reperfusion injury and cardiac transplantation support our hypothesis. CONCLUSION: The innate anti-inflammatory mechanism of IgM-ALA can be exploited by using purified normal IgM to inhibit inflammatory states or by a vaccine approach to increase in vivo production of IgM-ALA (e.g., prior to a transplant). PMID: 20401525 [PubMed - indexed for MEDLINE] | | | | | | | | | | | | | | | | | | | | | | | | | Wound healing effects of gingival fibroblasts cultured in animal-free medium. Oral Dis. 2010 Jul;16(5):438-44 Authors: Nishi H, Ohta K, Takechi M, Yoneda S, Hiraoka M, Kamata N OBJECTIVE: The purpose of this study was to develop a graft material made of gingival fibroblasts cultured in animal-free medium (HFDM1). METHODS: We examined the effects of human serum (HS) on cell growth and wound healing capability, demonstrated by cytokine production, of gingival fibroblasts cultured in HFDM1. Subsequently, the capability of fibroblasts cultured in HFDM1 with 2% HS to promote the healing of skin defects was evaluated using nude mice. RESULTS: The proliferation of human gingival fibroblasts was increased when HS at a concentration of 0.5-2% was added to HFDM1. Wound healing cytokines, including transforming growth factor-beta, keratinocyte growth factor, hepatocyte growth factor, vascular endothelial growth factor, and IL-6 produced by gingival fibroblasts were increased by adding 2% HS to HFDM1. In addition, gingival fibroblasts cultured in HFDM1 with 2% HS improved wound healing of mouse skin defects as well as those cultured in Dulbecco's modified Eagle's medium with 10% fetal calf serum. CONCLUSION: Gingival fibroblasts cultured in HFDM1 with 2% HS may be useful as a graft material for reconstruction. PMID: 20233319 [PubMed - indexed for MEDLINE] | | | | | | | | | | | | | | | | | | | | | | | | | Adult equine bone marrow stromal cells produce a cartilage-like ECM mechanically superior to animal-matched adult chondrocytes. Matrix Biol. 2010 Jun;29(5):427-38 Authors: Kopesky PW, Lee HY, Vanderploeg EJ, Kisiday JD, Frisbie DD, Plaas AH, Ortiz C, Grodzinsky AJ Our objective was to evaluate the age-dependent mechanical phenotype of bone marrow stromal cell- (BMSC-) and chondrocyte-produced cartilage-like neo-tissue and to elucidate the matrix-associated mechanisms which generate this phenotype. Cells from both immature (2-4 month-old foals) and skeletally-mature (2-5 year-old adults) mixed-breed horses were isolated from animal-matched bone marrow and cartilage tissue, encapsulated in self-assembling-peptide hydrogels, and cultured with and without TGF-beta1 supplementation. BMSCs and chondrocytes from both donor ages were encapsulated with high viability. BMSCs from both ages produced neo-tissue with higher mechanical stiffness than that produced by either young or adult chondrocytes. Young, but not adult, chondrocytes proliferated in response to TGF-beta1 while BMSCs from both age groups proliferated with TGF-beta1. Young chondrocytes stimulated by TGF-beta1 accumulated ECM with 10-fold higher sulfated-glycosaminoglycan content than adult chondrocytes and 2-3-fold higher than BMSCs of either age. The opposite trend was observed for hydroxyproline content, with BMSCs accumulating 2-3-fold more than chondrocytes, independent of age. Size-exclusion chromatography of extracted proteoglycans showed that an aggrecan-like peak was the predominant sulfated proteoglycan for all cell types. Direct measurement of aggrecan core protein length and chondroitin sulfate chain length by single molecule atomic force microscopy imaging revealed that, independent of age, BMSCs produced longer core protein and longer chondroitin sulfate chains, and fewer short core protein molecules than chondrocytes, suggesting that the BMSC-produced aggrecan has a phenotype more characteristic of young tissue than chondrocyte-produced aggrecan. Aggrecan ultrastructure, ECM composition, and cellular proliferation combine to suggest a mechanism by which BMSCs produce a superior cartilage-like neo-tissue than either young or adult chondrocytes. PMID: 20153827 [PubMed - indexed for MEDLINE] | | | | | | | | | | | | | | | | | | | | | | | | | Absorption-based assays for the analysis of osteogenic and chondrogenic yield. Methods Mol Biol. 2011;690:255-72 Authors: Davis LA, Dienelt A, Nieden NI The typical characteristics of cartilage and bone tissue are their unique extracellular matrices on which our body relies for structural support. In the respective tissue, the cells that create these matrices are the chondrocyte and the osteoblast. During in vitro differentiation from an embryonic or any other stem cell, specific cell types must be unequivocally identifiable to be able to draw the conclusion that a specific cell type has indeed been generated. Here, gene expression profiling can be helpful, but examining functional properties of cells is a lot more conclusive. As proteoglycans are found in and are part of the function of cartilage tissue, their detection and quantification becomes an important diagnostic tool in tissue engineering. Likewise, in bone regeneration therapy and in research, alkaline phosphatase is a known marker to detect the degree of development and function of differentiating osteoblasts. Calcification of the maturing osteoblast is the last stage in its development, and thus, the quantification of deposited calcium can aid in determining how many cells in a given culture have successfully matured into fully functioning osteoblasts. This chapter describes methods ideal for testing of proteoglycan content, alkaline phosphatase activity, and calcium deposit during in vitro chondro- and osteogenesis. PMID: 21042998 [PubMed - in process] | | | | | | | | | | | | | | | | | | | | | | | | | Differentiation of mouse embryonic stem cells in self-assembling Peptide scaffolds. Methods Mol Biol. 2011;690:217-37 Authors: Marí-Buyé N, Semino CE Here, we describe the capacity of mouse embryonic stem cells (mESCs) to differentiate into osteoblast-like cells in a three-dimensional (3D) self-assembling peptide scaffold, a synthetic nanofiber biomaterial with future applications in regenerative medicine. We have previously demonstrated that classical tissue cultures (two-dimensional) as well as 3D-systems promoted differentiation of mESCs into cells with an osteoblast-like phenotype expressing osteopontin (OPN) and collagen type I (Col I), as well as high alkaline phosphatase (Alk Phos) activity and calcium phosphate mineralization. Interestingly, in 3D self-assembling peptide scaffold cultures, the frequency of appearance of embryonic stem-cell-like colonies was substantially enhanced, suggesting that this particular 3D microenvironment promoted the generation of a stem-cell-like niche that allows the maintenance of a small pool of undifferentiated cells. We propose that the 3D system provides a unique microenvironment permissive to promote differentiation of mESCs into osteoblast-like cells while maintaining its regenerative capacity. PMID: 21042996 [PubMed - in process] | | | | | | | | | | | | | | | | | | | | | | | | | Manipulations of MicroRNA in Human Pluripotent Stem Cells and Their Derivatives. Methods Mol Biol. 2011;690:107-20 Authors: Rushing SN, Herren AW, Lieu DK, Li RA Human embryonic stem cells (hESCs) and induced pluripotent stem cells (iPSCs) reprogrammed from somatic cells can self-renew while maintaining their pluripotency to differentiate into virtually all cell types. In addition to their potential for regenerative medicine, hESCs and iPSCs can also serve as excellent in vitro models for the study of human organogenesis and disease models, as well as drug toxicity screening. MicroRNAs (miRNAs) are nonencoding RNAs of ∼22 nucleotides that function as negative transcriptional regulators via degradation or inhibition by RNA interference (RNAi). MiRNAs play essential roles in developmental pathways. This chapter provides a description of how miRNAs can be introduced into hESCs/iPSCs or their derivatives for experiments via lentivirus-mediated gene transfer. PMID: 21042988 [PubMed - in process] | | | | | | | | | | | | | | | | | | | | | | | | | Using cadherin expression to assess spontaneous differentiation of embryonic stem cells. Methods Mol Biol. 2011;690:81-94 Authors: Spencer H, Keramari M, Ward CM Embryonic stem cells (ESCs) are pluripotent cells derived from preimplantation embryos and can be maintained in an undifferentiated state over prolonged periods in vitro. In addition, ESCs can be induced to differentiate into cells representative of the three primary germ layers. As such, ESCs are a useful system for studying early developmental events in vitro and have the potential to provide a ubiquitous supply of somatic cells for use in regenerative medicine. However, significant differences in the expression pattern of various cell surface markers between murine and human ESCs, e.g. the SSEA series, necessitate the use of separate markers for determining the undifferentiated state of these cells. We have recently shown that an E- to N-cadherin switch occurs during spontaneous differentiation of both murine and human ESCs. Here we describe the use of E-cadherin and N-cadherin proteins and transcript expression for assessing the proportion of undifferentiated and spontaneously differentiated cells within ESC populations. In summary, loss of cell surface E-cadherin and/or gain of N-cadherin protein expression provides a useful nondestructive assay for the determination of the proportion of spontaneously differentiated cells within an ESC population. In addition, presence of N-cadherin transcripts in an ESC population is indicative of spontaneous differentiation of a proportion of the cells. PMID: 21042986 [PubMed - in process] | | | | | | | | | | | | | | | | | | | | | | | | | 3D Structuring of Biocompatible and Biodegradable Polymers Via Stereolithography. Methods Mol Biol. 2011;695:309-21 Authors: Gill AA, Claeyssens F The production of user-defined 3D microstructures from biocompatible and biodegradable materials via free-form fabrication is an important step to create off-the-shelf technologies to be used as tissue engineering scaffolds. One method of achieving this is the microstereolithography of block copolymers, allowing high resolution microstructuring of materials with tuneable physical properties. A versatile protocol for the production and photofunctionalisation of pre-polymers for microstereolithography is presented along with a discussion of the possible microstereolithography set-ups and previous work in the field. PMID: 21042980 [PubMed - in process] | | | | | | | | | | | | | | | | | | | | | | | | | Practical Aspects of OCT Imaging in Tissue Engineering. Methods Mol Biol. 2011;695:261-80 Authors: Matcher SJ Optical coherence tomography (OCT) is a non-destructive, non-invasive imaging modality conceptually similar to ultrasound imaging but uses near-infrared radiation rather than sound. It is attracting interest throughout the medical community as a tool for ophthalmic scanning (especially of the retina) and potentially for the diagnosis of many other illnesses such as epithelial cancer, connective tissue disorders, and atherosclerosis, as well as for surgical guidance. More recently, it has begun to be explored as a tool for the real-time monitoring of the growth and development of tissue-engineered products. OCT has certain unique advantages over traditional confocal microscopy; in particular, it can image to depths measured in hundreds of microns rather than tens of microns in intact biological tissues and with working distances in excess of 1 cm. Also it possesses label-free contrast for imaging ordered collagen (via birefringence), flow velocity and local shear-rate (via Doppler shifts), and sub-cellular structure (via coherent speckle contrast). The purpose of this short review is to introduce OCT technology and also give guidelines on its practical implementation to the interested researcher. PMID: 21042978 [PubMed - in process] | | | | | | | | | | | | | | | | | | | | | | | | | Organotypic and 3D Reconstructed Cultures of the Human Bladder and Urinary Tract. Methods Mol Biol. 2011;695:197-211 Authors: Varley CL, Southgate J Three-dimensional organotypic cultures of human urinary tract tissue have been established as intact and reconstituted tissues, with the latter generated by combining cultured normal human urothelial (NHU) cells with an appropriate stroma. Organoids may be maintained at an air-liquid interface in static culture for periods of up to 20 weeks, with analysis by immunohistology for expression of urothelial differentiation-associated markers providing a qualitative, but objective assessment criterion. Where reconstructed using bladder cancer cell lines, the resultant organoids recapitulate the invasive characteristics of the originating tumour, but the need to use authenticated cell line stocks is emphasised. The organoid approach represents an important tool for investigating urothelial-stromal cell interactions during homeostasis and disease, and for testing bladder tissue engineering and reconstructive strategies. Potential future developments of the technique are discussed and include genetic manipulation of the urothelial cells to generate disease models and incorporation of biomaterial scaffolds to support artificial stroma development. PMID: 21042974 [PubMed - in process] | | | | | | | | | | | | | | | | | | | | | | | | | Encapsulation of Human Articular Chondrocytes into 3D Hydrogel: Phenotype and Genotype Characterization. Methods Mol Biol. 2011;695:167-81 Authors: Pereira RC, Gentili C, Cancedda R, Azevedo HS, Reis RL This chapter is intended to provide a summary of the current materials used in cell encapsulation technology as well as methods for evaluating the performance of cells encapsulated in a polymeric matrix. In particular, it describes the experimental procedure to prepare a hydrogel matrix based on natural polymers for encapsulating and culturing human articular chondrocytes with the interest in cartilage regeneration. Protocols to evaluate the viability, proliferation, differentiation, and matrix production of embedded cells are also described and include standard protocols such as the MTT and [3H] Thymidine assays, reverse transcription polymerase chain reaction (RT-PCR) technique, histology, and immunohistochemistry analysis. The assessment of cell distribution within the 3D hydrogel construct is also described using APoTome analysis. PMID: 21042972 [PubMed - in process] | | | | | | | | | | | | | | | | | | | | | | | | | Stem Cell and Neuron Co-cultures for the Study of Nerve Regeneration. Methods Mol Biol. 2011;695:115-27 Authors: Kingham PJ, Mantovani C, Terenghi G Many experimental in vivo studies have indicated that Schwann cells are key facilitators of peripheral nerve regeneration but their clinical therapeutic potential may be limited. Recent advances suggest that stem cell therapy could one day be used to treat nerve traumas. We have shown how adult stem cells can be differentiated into a Schwann cell phenotype, characterised by expression of glial cell proteins and promotion of neurite outgrowth. The development of new cell culture models which mimic the in vivo regeneration environment will help us to better understand the functional benefits of these cells. Here, we describe a stepwise approach towards this, moving from traditional two-dimensional non-contact co-cultures to new three-dimensional models utilising fibrin matrices. PMID: 21042969 [PubMed - in process] | | | | | | | | | | | | | | | | | | | | | | | | | Genetic modification of chondrocytes using viral vectors. Methods Mol Biol. 2011;695:99-114 Authors: Coughlan T, Crawford A, Hatton P, Barker M The use of isolated cells to construct engineered tissues provides the opportunity to genetically modify those cells prior to the formation of tissue. This should make it possible to create transgenic human model tissues that can be used to determine gene function as well as to identify or validate potential therapeutic targets. As proof of principle, we have used RNA interference to selectively suppress the expression of aggrecanase genes in human chondrocytes, in an attempt to determine which of these key enzymes have roles in arthritic cartilage destruction. This combination of gene targeting and tissue engineering we are using should be equally applicable to the identification of gene function in other biological systems. PMID: 21042968 [PubMed - in process] | | | | | | | | | | | | | | | | | | | | | | | | | 3D Sample Preparation for Orthopaedic Tissue Engineering Bioreactors. Methods Mol Biol. 2011;695:61-76 Authors: Cartmell SH, Rathbone S, Jones G, Hidalgo-Bastida LA There are several types of bioreactors currently available for the culture of orthopaedic tissue engineered constructs. These vary from the simple to the complex in design and culture. Preparation of samples for bioreactors varies depending on the system being used. This chapter presents data and describes tried and tested methodologies for the preparation of 3D samples for a Rotatory Synthecon Bioreactor (Cellon), a plate shaker, a perfusion system, and a Bose Electroforce Systems Biodynamic Instrument for the in vitro culture of bone and ligament tissue. PMID: 21042966 [PubMed - in process] | | | | | | | | | | | | | | | | | | | | | | | | | Using Immuno-Scanning Electron Microscopy for the Observation of Focal Adhesion-substratum interactions at the Nano- and Microscale in S-Phase Cells. Methods Mol Biol. 2011;695:53-60 Authors: Biggs MJ, Richards RG, Dalby MJ It is becoming clear that the nano/microtopography of a biomaterial in vivo is of first importance in influencing focal adhesion formation and subsequent cellular behaviour. When considering next-generation biomaterials, where the material's ability to elicit a regulated cell response will be key to device success, focal adhesion analysis is an useful indicator of cytocompatibility and can be used to determine functionality. Here, a methodology is described to allow simultaneous high-resolution imaging of focal adhesion sites and the material topography using field emission scanning electron microscopy. Furthermore, through the use of BrdU pulse labelling and immunogold detection, S-phase cells can be selected from a near-synchronised population of cells to remove artefacts due to cell cycle phase. This is a key factor in adhesion quantification as there is natural variation in focal adhesion density as cells progress through the cell cycle, which can skew the quantitative analysis of focal adhesion formation on fabricated biomaterials. PMID: 21042965 [PubMed - in process] | | | | | | | | | | | | | | | | | | | | | | | | | Scaffolds for Tissue Engineering and 3D Cell Culture. Methods Mol Biol. 2011;695:17-39 Authors: Carletti E, Motta A, Migliaresi C In tissue engineering applications or even in 3D cell cultures, the biological cross talk between cells and the scaffold is controlled by the material properties and scaffold characteristics. In order to induce cell adhesion, proliferation, and activation, materials used for the fabrication of scaffolds must possess requirements such as intrinsic biocompatibility and proper chemistry to induce molecular biorecognition from cells. Materials, scaffold mechanical properties and degradation kinetics should be adapted to the specific tissue engineering application to guarantee the required mechanical functions and to accomplish the rate of the new-tissue formation. For scaffolds, pore distribution, exposed surface area, and porosity play a major role, whose amount and distribution influence the penetration and the rate of penetration of cells within the scaffold volume, the architecture of the produced extracellular matrix, and for tissue engineering applications, the final effectiveness of the regenerative process. Depending on the fabrication process, scaffolds with different architecture can be obtained, with random or tailored pore distribution. In the recent years, rapid prototyping computer-controlled techniques have been applied to the fabrication of scaffolds with ordered geometry. This chapter reviews the principal polymeric materials that are used for the fabrication of scaffolds and the scaffold fabrication processes, with examples of properties and selected applications. PMID: 21042963 [PubMed - in process] | | | | | | | | | | | | | | | | | | | | | | | | | Regulatory T-Cell Generation and Kidney Allograft Tolerance Induced by Mesenchymal Stem Cells Associated With Indoleamine 2,3-Dioxygenase Expression. Transplantation. 2010 Oct 29; Authors: Ge W, Jiang J, Arp J, Liu W, Garcia B, Wang H BACKGROUND.: The immunoregulatory properties of mesenchymal stem cells (MSCs) have been observed in vitro and in vivo. However, the underlying mechanisms of this immunomodulation remain undefined. Recent research demonstrated that MSCs express the tryptophan-catabolizing enzyme indoleamine 2,3-dioxygenase (IDO), known to suppress T-cell responses. This study was designed to address whether MSCs induce kidney allograft tolerance and whether IDO contributes to the immunoregulatory functions of MSCs in vivo. METHODS.: MSCs (1×10, intravenously) from wild-type (WT-MSCs) or IDO knockout (IDO-MSCs) C57BL/6 mice were injected into BALB/c recipients 24 hr after receiving a life-supporting orthotopic C57BL/6 renal graft. RESULTS.: WT-MSC-treated recipients achieved allograft tolerance with normal histology and undetectable antidonor antibody levels. Tolerant recipients demonstrated increased circulating kynurenine levels and significantly high frequencies of tolerogenic dendritic cells. They also exhibited significantly impaired CD4 T-cell responses consisting of decreased donor-specific proliferative ability and a Th2-dominant cytokine shift. In addition, high frequencies of CD4CD25Foxp3 regulatory T cells (Tregs) were found in recipient spleens and donor grafts, with antibody-induced CD25 cell depletion confirming the critical role of Tregs in the MSC-induced tolerance. Interestingly, renal allograft recipients treated with WT MSCs concomitant with the IDO inhibitor 1-methyl-tryptophan, or those treated with IDO-MSCs alone, were unable to achieve allograft tolerance-revealing that functional IDO was necessary for the immunosuppression observed with WT-MSC treatment. CONCLUSIONS.: IDO secreted by MSCs was responsible, at least in part, for induction of kidney allograft tolerance through generation of Tregs. This study supports the clinical application of MSCs in transplantation. PMID: 21042238 [PubMed - as supplied by publisher] | | | | | | | | | | | | | | | | | | | | | | | | | Mesenchymal Stem Cells Transduced by Stromal Cell-Derived Factor-1α Augment Ischemic Free Flaps Survival. Ann Plast Surg. 2010 Oct 29; Authors: Zhang FG, Yao Y, Feng Y, Hua CG, Tang XF Mesenchymal stem cells (MSCs) have the potential for differentiating into vascular endothelial cells. Stromal cell-derived factor-1α (SDF-1α) plays an important role in neovascularization of ischemic flaps. The authors evaluated the feasibility of applying MSCs transduced by SDF-1α gene to the treatment of early and partial ischemic free flaps survival. MSCs were isolated from Lewis rats and cultured in vitro. Recombinant adenovirus encoding SDF-1α gene (Ad-SDF-1α) was transduced into the MSCs. Lewis rats that underwent epigastric free flaps based on medial and lateral branches of superficial inferior epigastric vessels and femoral vessels were equally randomized into 4 groups, and injected with Ad-SDF-1α-transduced MSCs, MSCs, Ad-SDF-1α, and normal saline, respectively. Gene transduction, flaps survival, neovascularization, and expression level of SDF-1a protein were detected. The results showed that Ad-SDF-1α-transduced MSCs expressed higher SDF-1α both in vitro and in vivo, yielded more survival area, and resulted in higher neovascularization than any other groups. Interestingly, the necrotic sites of all free flaps were in the proximal end rather than in the distal end. In conclusion, Ad-SDF-1α-transduced MSCs can increase neovascularization of early and partial ischemic free flaps and augment the surviving areas. PMID: 21042172 [PubMed - as supplied by publisher] | | | | | | | | | | | | | | | | | | | | | | | | | Tissue engineering (academic press series in biomedical engineering). Plast Reconstr Surg. 2010 Nov;126(5):1784 Authors: Brown SA PMID: 21042141 [PubMed - in process] | | | | | | | | | | | | | | | | | | | | | | | | | The basic science of vascular biology: implications for the practicing surgeon. Plast Reconstr Surg. 2010 Nov;126(5):1528-38 Authors: Glotzbach JP, Levi B, Wong VW, Longaker MT, Gurtner GC SUMMARY:: A thorough understanding of vascular biology will assist the reconstructive surgeon in both operative planning and development of novel surgical approaches to treat chronic wounds and tissue loss, and to optimize regenerative strategies for tissue reconstruction. In this review, several fundamental concepts of the basic science of vascular biology are discussed, with specific emphasis on the clinical implications most relevant to the reconstructive surgeon. Topics include the vascular physiology of tissue flaps and grafts, the principles of neovascularization including angiogenesis and vasculogenesis, and the basic concepts of bioengineering of vascularized tissue constructs for use in reconstruction. As basic science research increases our collective understanding of vascular physiology-specifically, in the areas of neovascularization and tissue engineering-reconstructive surgeons will be able to improve treatment of the sequelae of ischemic injuries, tissue loss, and chronic wounds. PMID: 21042110 [PubMed - in process] | | | | | | | | | | | | | | | | | | | | | | | | | Local anesthetics have a major impact on viability of preadipocytes and their differentiation into adipocytes. Plast Reconstr Surg. 2010 Nov;126(5):1500-5 Authors: Keck M, Zeyda M, Gollinger K, Burjak S, Kamolz LP, Frey M, Stulnig TM BACKGROUND:: Autologous fat transplantation is a well-established technique in surgery. Moreover, the use of preadipocytes in soft-tissue engineering is currently being intensely investigated. Current efforts focus on identifying maneuvers that may minimize resorption and provide predictable late results. The aim of this study was to investigate the influence of different local anesthetics frequently used in clinical practice on the viability of preadipocytes and their ability to differentiate into adipocytes. METHODS:: Human preadipocytes were isolated from subcutaneous adipose tissue of 15 patients and treated with bupivacaine, mepivacaine, ropivacaine, articaine/epinephrine, and lidocaine for 30 minutes. Viability was determined directly after treatment and during the ensuing cultivation. Differentiation of preadipocytes was determined by expression of the adipocyte marker adiponectin. RESULTS:: Although the immediate effects of mepivacaine and ropivacaine were only moderate, treatment with articaine/epinephrine and lidocaine strongly impaired preadipocyte viability. Cells normally attached to the culture dishes and proliferated irrespective of the previous treatment. During long-term cultivation, articaine/epinephrine-treated cell viability decreased markedly, whereas other local anesthetics had no impact. Despite normal phenotypic appearance of cells treated with bupivacaine, mepivacaine, ropivacaine, and lidocaine, all local anesthetics markedly impaired adipocyte differentiation as determined by adiponectin expression. CONCLUSIONS:: The authors' results show that there is a marked influence of local anesthetics not only on the quantity but also on the quality of viable preadipocytes as determined by their ability to differentiate into mature adipocytes. Therefore, these results should be considered in the context of autologous fat transfer and soft-tissue engineering. PMID: 21042106 [PubMed - in process] | | | | | | | | | | | | | | | | | | | | | | | | | Editorial: Are men rats? Dendritic cells in autoimmune glomerulonephritis. J Leukoc Biol. 2010 Nov;88(5):831-5 Authors: Sung SS, Bolton WK PMID: 21041514 [PubMed - in process] | | | | | | | | | | | | | | | | | | | | | | | | | Wnt11 promotes cardiomyocyte development by caspase-mediated suppression of canonical Wnt signals. Mol Cell Biol. 2010 Nov 1; Authors: Abdul-Ghani M, Dufort D, Stiles R, De Repentigny Y, Kothary R, Megeney LA Specification and early patterning of the vertebrate heart is dependent on both canonical and non-canonical wingless (Wnt) signal pathways. However, the impact of each Wnt pathway on the later stages of myocardial development and differentiation remains controversial. Here, we report that the components of each Wnt signal conduit are expressed in the developing and post-natal heart, yet canonical/β-catenin activity is restricted to non-myocardial regions. Subsequently, we observed that a non-canonical Wnt (Wnt11) enhanced myocyte differentiation, while preventing stabilization of the β-catenin protein, suggesting active repression of canonical Wnt signals. Wnt11 stimulation was synonymous with activation of a caspase 3 signal cascade, while inhibition of caspase activity led to accumulation of β-catenin and a dramatic reduction in myocyte differentiation. Taken together, these results suggest that non-canonical Wnt signals promote myocyte maturation through caspase mediated inhibition of β-catenin activity. PMID: 21041481 [PubMed - as supplied by publisher] | | | | | | | | | | | | | | | | | | | | | | | | | Epigenetic control of retrotransposon expression in human embryonic stem cells. Mol Cell Biol. 2010 Nov 1; Authors: Macia A, Muñoz-Lopez M, Cortes JL, Hastings RK, Morell S, Lucena-Aguilar G, Marchal JA, Badge RM, Garcia-Perez JL Long Interspersed Element-1s (LINE-1s or L1s) are a family of non-LTR retrotransposons that predominate in the human genome. Active LINE-1 elements encode proteins required for their mobilization. L1-encoded proteins also act in trans to mobilize Short Interspersed Elements (SINEs), such as Alu elements. L1 and Alu insertions have been implicated in many human diseases, and their retrotransposition provides an ongoing source of human genetic diversity. L1/Alu elements are expected to ensure their transmission to subsequent generations by retrotransposing in germ cells or during early embryonic development. Here, we determined that several subfamilies of Alu elements are expressed in undifferentiated Human Embryonic Stem Cells (hESCs), and that most expressed Alus are active elements. We also exploited expression from the L1 antisense promoter to map expressed elements in hESCs. Remarkably, we found that expressed Alu elements are enriched in the youngest subfamily Y, and that expressed L1s are mostly located within genes, suggesting an epigenetic control of retrotransposon expression in hESCs. Together, these data suggest that distinct subsets of active L1/Alu elements are expressed in hESCs, and that the degree of somatic mosaicism attributable to L1 insertions during early development may be higher than previously anticipated. PMID: 21041477 [PubMed - as supplied by publisher] | | | | | | | | | | | | | | | | | | | | | | | | | Epigenetic Mechanisms that Regulate Cell Identity. Cell Stem Cell. 2010 Nov 5;7(5):565-70 Authors: Barrero MJ, Boué S, Izpisúa Belmonte JC Individual cell fate decisions can vary according to changes in gene expression in response to environmental, developmental, or metabolic cues. This plasticity is tightly regulated during embryonic development and mediated by the exquisitely coordinated activation and repression of groups of genes. Genes that become repressed are immersed in a condensed chromatin environment that renders them refractory to stimulation. This mechanism is responsible for both the loss of cell plasticity during differentiation and the preservation of cell identity. Understanding the molecular events involved in the establishment and maintenance of these restrictive domains will benefit the design of strategies for cellular reprogramming, differentiation, and cancer treatment. PMID: 21040898 [PubMed - in process] | | | | | | | | | | | | | | | | | | | | | | | | | Different flavors of pluripotency, molecular mechanisms, and practical implications. Cell Stem Cell. 2010 Nov 5;7(5):559-64 Authors: Buecker C, Geijsen N Pluripotent stem cells (PSCs) have been classified into two distinct states: a primitive, naive LIF-dependent state represented by murine ESCs, and a primed bFGF-dependent state observed in murine and rat epiblast stem cells (EpiSCs). The vast similarities between EpiSCs and human ESCs suggest that, despite their blastocyst origin, human ESCs exist in a primed pluripotent state. Recent findings demonstrate that the naive and primed pluripotent states are interconvertible, even in human cells, and hint that growth factor-mediated Nanog expression may be an important factor regulating the balance between them. PMID: 21040897 [PubMed - in process] | | | | | | | | | | | | | | | | | | | | | | | | | Adipose-derived mesenchymal stem cells protect PC12 cells from glutamate excitotoxicity-induced apoptosis by upregulation of XIAP through PI3-K/Akt activation. Toxicology. 2010 Oct 29; Authors: Lu S, Lu C, Han Q, Li J, Du Z, Liao L, Zhao RC Glutamate excitotoxicity has been implicated as one of the factors contributing to neuronal apoptosis and is involved in many neurodegenerative diseases. Previous studies suggest that mesenchymal stem cells have the ability to protect cultured neurons from excitotoxicity-induced apoptosis, although the underlying mechanisms are not clear. In this study, we evaluated whether adipose mesenchymal stem cells (AMSCs) could protect against glutamate-induced injury in PC12 cells by secreting neurotrophic factors. We found that AMSCs secreted neurotrophic factors including vascular endothelial growth factor (VEGF), hepatocyte growth factor (HGF), brain-derived neurotrophic factor (BDNF) and nerve growth factor (NGF) under both normoxic and hypoxic conditions. AMSC - conditioned medium (AMSC-CM) had a protective effect on excitotoxicity-injured PC12 cells, as indicated by increased cell viability, decreased number of TUNEL-staining positive nuclei and lowered caspase-3 activity. By using neutralizing monoclonal antibodies and specific inhibitors, VEGF, HGF and BDNF were identified as the mediators of AMSC effects and PI3-K/Akt and MAPK pathways were involved. Western blot analysis showed that AMSC-CM can increase the level of p-Akt, up-regulate XIAP and reduce the level of cleaved-caspase-3 in PC12 cells. These results suggest that AMSCs can effectively protect PC12 cells from glutamate excitotoxicity-induced apoptosis and support the hypothesis that AMSCs may be a useful treatment for stroke or neurodegenerative diseases which often involve excitotoxicity. PMID: 21040751 [PubMed - as supplied by publisher] | | | | | | | | | | | | | | | | | | | | | | | | | Embryonic and Embryonic-like Stem Cells in Heart Muscle Engineering. J Mol Cell Cardiol. 2010 Oct 29; Authors: Zimmermann WH Cardiac muscle engineering is evolving rapidly and may ultimately be exploited to (1) model cardiac development, physiology and pathology, (2) identify and validate drug targets, (3) assess drug safety and efficacy, and (4) provide therapeutic substitute myocardium. The ultimate success in any of these envisioned applications depends on the utility of human cells and their assembly into myocardial equivalents with structural and functional properties of mature heart muscle. Embryonic stem cells appear as a promising cell source in this respect, because they can be cultured reliably and differentiated robustly into cardiomyocytes. Despite their unambiguous cardiogenicity, data on advanced maturation and seamless myocardial integration of embryonic stem cell-derived cardiomyocytes in vivo are sparse. Additional concerns relate to the limited control over cardiomyogenic specification and cardiomyocyte maturation in vitro as well as the risk of teratocarcinoma formation and immune rejection of stem cell implants in vivo. Through the invent of embryonic-like stem cells - such as parthenogenetic stem cells, male germline stem cells, and induced pluripotent stem cells - some, but certainly not all of these issues may be addressed, albeit at the expense of additional concerns. This review will discuss the applicability of embryonic and embryonic-like stem cells in myocardial tissue engineering and address issues that require particular attention before the potential of stem cell-based heart muscle engineering may be fully exploited. PMID: 21040727 [PubMed - as supplied by publisher] | | | | | | | | | | | | | | | | | | | | | | | | | Summary of the Recommendations on Sexual Dysfunctions in Men. J Sex Med. 2010 Nov;7(11):3572-3588 Authors: Montorsi F, Adaikan G, Becher E, Giuliano F, Khoury S, Lue TF, Sharlip I, Althof SE, Andersson KE, Brock G, Broderick G, Burnett A, Buvat J, Dean J, Donatucci C, Eardley I, Fugl-Meyer KS, Goldstein I, Hackett G, Hatzichristou D, Hellstrom W, Incrocci L, Jackson G, Kadioglu A, Levine L, Lewis RW, Maggi M, McCabe M, McMahon CG, Montague D, Montorsi P, Mulhall J, Pfaus J, Porst H, Ralph D, Rosen R, Rowland D, Sadeghi-Nejad H, Shabsigh R, Stief C, Vardi Y, Wallen K, Wasserman M Introduction. Sexual health is an integral part of overall health. Sexual dysfunction can have a major impact on quality of life and psychosocial and emotional well-being. Aim. To provide evidence-based, expert-opinion consensus guidelines for clinical management of sexual dysfunction in men. Methods. An international consultation collaborating with major urologic and sexual medicine societies convened in Paris, July 2009. More than 190 multidisciplinary experts from 33 countries were assembled into 25 consultation committees. Committee members established scope and objectives for each chapter. Following an exhaustive review of available data and publications, committees developed evidence-based guidelines in each area. Main Outcome Measures. New algorithms and guidelines for assessment and treatment of sexual dysfunctions were developed based on work of previous consultations and evidence from scientific literature published from 2003 to 2009. The Oxford system of evidence-based review was systematically applied. Expert opinion was based on systematic grading of medical literature, and cultural and ethical considerations. Results. Algorithms, recommendations, and guidelines for sexual dysfunction in men are presented. These guidelines were developed in an evidence-based, patient-centered, multidisciplinary manner. It was felt that all sexual dysfunctions should be evaluated and managed following a uniform strategy, thus the International Consultation of Sexual Medicine (ICSM-5) developed a stepwise diagnostic and treatment algorithm for sexual dysfunction. The main goal of ICSM-5 is to unmask the underlying etiology and/or indicate appropriate treatment options according to men's and women's individual needs (patient-centered medicine) using the best available data from population-based research (evidence-based medicine). Specific evaluation, treatment guidelines, and algorithms were developed for every sexual dysfunction in men, including erectile dysfunction; disorders of libido, orgasm, and ejaculation; Peyronie's disease; and priapism. Conclusions. Sexual dysfunction in men represents a group of common medical conditions that need to be managed from a multidisciplinary perspective. Montorsi F, Adaikan G, Becher E, Giuliano F, Khoury S, Lue TF, Sharlip I, Althof SE, Andersson K-E, Brock G, Broderick G, Burnett A, Buvat J, Dean J, Donatucci C, Eardley I, Fugl-Meyer KS, Goldstein I, Hackett G, Hatzichristou D, Hellstrom W, Incrocci L, Jackson G, Kadioglu A, Levine L, Lewis RW, Maggi M, McCabe M, McMahon CG, Montague D, Montorsi P, Mulhall J, Pfaus J, Porst H, Ralph D, Rosen R, Rowland D, Sadeghi-Nejad H, Shabsigh R, Stief C, Vardi Y, Wallen K, and Wasserman M. Summary of the recommendations on sexual dysfunctions in men. J Sex Med 2010;7:3572-3588. PMID: 21040491 [PubMed - as supplied by publisher] | | | | | | | | | | | | | | | | | | | | | | | | | In vitro and in vivo properties of distinct populations of amniotic fluid mesenchymal progenitor cells. J Cell Mol Med. 2010 Sep 27; Authors: Roubelakis MG, Bitsika V, Zagoura D, Trohatou O, Pappa KI, Makridakis M, Antsaklis A, Vlahou A, Anagnou NP Human mesenchymal progenitor cells (MPCs) are considered to be of great promise for use in tissue repair and regenerative medicine. MPCs represent multipotent adherent cells, able to give rise to multiple mesenchymal lineages such as osteoblasts, adipocytes or chondrocytes. Recently, we identified and characterized human second trimester amniotic fluid (AF) as a novel source of MPCs. Herein, we found that early colonies of AF-MPCs consisted of two morphologically distinct adherent cell types, termed as spindle-shaped (SS) and round-shaped (RS). A detailed analysis of these two populations showed that SS-AF-MPCs expressed CD90 antigen in a higher level and exhibited a greater proliferation and differentiation potential. To characterize better the molecular identity of these two populations, we have generated a comparative proteomic map of SS-AF-MPCs and RS-AF-MPCs, identifying 25 differentially expressed proteins and 10 proteins uniquely expressed in RS-AF-MPCs. Furthermore, SS-AF-MPCs exhibited significantly higher migration ability on extracellular matrices, such as fibronectin and laminin in vitro, compared to RS-AF-MPCs and thus we further evaluated SS-AF-MPCs for potential use as therapeutic tools in vivo. Therefore, we tested whether GFP-lentiviral transduced SS-AF-MPCs retained their stem cell identity, proliferation and differentiation potential. GFP-SS-AF-MPCs were then successfully delivered into immunosuppressed mice, distributed in different tissues and survived longterm in vivo. In summary, these results demonstrated that AF-MPCs consisted of at least two different MPC populations. Additionally, SS-AF-MPCs, isolated based on their colony morphology and CD90 expression, represented the only MPC population that can be expanded easily in culture and used as an efficient tool for future in vivo therapeutic applications. PMID: 21040455 [PubMed - as supplied by publisher] | | | | | | | | | | | | | | | | | | | | | | | | | Strategies in cardiac tissue engineering. ANZ J Surg. 2010 Oct;80(10):683-93 Authors: Tee R, Lokmic Z, Morrison WA, Dilley RJ In heart failure, post-myocardial infarction and some congenital cardiac anomalies, organ transplantation is the only effective cure. Shortage of organ donors and complications of orthotopic heart transplant remain major challenges to the modern field of transplantation. Tissue engineering using cell-based strategies presents itself as a new way of generating functional myocardium. Engineering functional myocardium de novo requires an abundant source of cells that can form cardiomyocytes. These cells may be used with biocompatible scaffold materials to generate a contractile myocardium. Lastly, to sustain the high metabolism of the construct, a functional vasculature needs to be developed with the forming cardiac tissue. This review provides an update on the progress of stem cell research in the context of cardiac tissue development, types of biomaterials used in cardiac tissue engineering (CTE) and currently employed strategies for vascularization in CTE. In addition, a brief overview of strategies utilized in CTE is provided. PMID: 21040327 [PubMed - in process] | | | | | | | | | | | | | | | | | | | | | | | | | Genistein and daidzein repress adipogenic differentiation of human adipose tissue-derived mesenchymal stem cells via Wnt/β-catenin signalling or lipolysis. Cell Prolif. 2010 Dec;43(6):594-605 Authors: Kim MH, Park JS, Seo MS, Jung JW, Lee YS, Kang KS Objectives: One aspect of the effects of isoflavones against fat deposition might be at least associated with the mechanism by which Wnt/β-catenin signalling inhibits adipocyte differentiation. However, it remains completely unknown as to whether isoflavones might influence Wnt signalling during commitment of pluripotent mesenchymal stem cells (MSCs) to adipose lineages. In the present study, we have investigated the mechanisms underlying effects of genistein and daidzein, the major soy isoflavones, on anti-adipogenic Wnt/β-catenin signalling. Materials and methods: Adipose tissue-derived (AD) MSCs were exposed continuously to genistein and daidzein (0.01-100 μm) during adipogenic differentiation (21 days). An oestrogen antagonist, ICI 182,780, was used to determine whether or not the isoflavones activated Wnt signalling via oestrogen receptors (ERs). Results: Genistein and daidzein suppressed adipogenic differentiation of AD-MSCs in a dose-dependent manner and inhibited expression of adipogenic markers, PPARγ, SREBP-1c and Glut 4, from mid-phase differentiation. Microarrays showed that anti-adipogenic effects of genistein were principally attributable to activation of Wnt signalling via ERs-dependent pathway, such as Erk/JNK signalling and LEF/TCF4 co-activators. These findings were supported by evidence that the effects of genistein were offset by ICI182,780. Unlike genistein, daidzein inhibited adipogenesis through stimulation of lipolysis, with for example, PKA-mediated hormone sensitive lipase. This is consistent with the increase in glycerol released from AD-MSCs. In conclusion, understanding that different sets of mechanisms of the two isoflavones on adipogenesis will help the design of novel strategies to prevent observed current epidemic levels of obesity, using isoflavones. PMID: 21039998 [PubMed - in process] | | | | | | | | | | | | | | | | | | | | | | | | | Crosslink Effect and Albumin Adsorption onto Chitosan/Alginate Multilayered Systems: An in situ QCM-D Study. Macromol Biosci. 2010 Oct 29; Authors: Martins GV, Merino EG, Mano JF, Alves NM The adsorption of HSA onto CHI/ALG multilayer assemblies was assessed in situ using QCM-D. It was found that the behavior of HSA on biomaterials surface can be tuned by adjusting parameters of the polyelectrolyte system such as pH, layer number, crosslinker and polymer terminal layer. Our results confirmed the key role of electrostatic interactions during HSA adsorption, since oppositely charged surfaces were more effective in promoting protein adhesion. QCM-D data revealed that crosslinking (CHI/ALG)(5)CHI films allows HSA to become adsorbed in physiological conditions. Our results suggested that the biological potential of biopolymers and the mild conditions of the LbL technique turn these natural nanoassemblies into a suitable choice to be used as pH-sensitive coatings. PMID: 21038348 [PubMed - as supplied by publisher] | | | | | | | | | | | | | | | | | | | | | | | | | Stem cells and regenerative medicine: potentials and realities for rhinology. Rhinology. 2010 Sep;48(3):259-64 Authors: Vats A, Birchall M It is widely believed that regenerative medicine, including stem cell-based technologies, will revolutionise healthcare in decades to come. Stem-cell treatments are already a reality and tissue engineering is moving deeper and deeper into the clinic. Various forms of stem cell and scaffold are in clinical trials and can be used alone, in combinations or supported by conventional treatments, such as drugs and free tissue transfer. It is likely that rhinology will also feel the winds of change very shortly. We review the present state-of-the art and a view of the future potential for regenerative medicine to influence care of patients with rhinologic disorders. PMID: 21038013 [PubMed - in process] | | | | | | | | | | | | | | | | | | | | | | | | | Cardiac innervation and sudden cardiac death. Curr Cardiol Rev. 2009 Nov;5(4):289-95 Authors: Ieda M, Fukuda K The heart is extensively innervated and its performance is tightly controlled by the nervous system. Cardiac innervation density varies in diseased hearts leading to unbalanced neural activation and lethal arrhythmia. Diabetic sensory neuropathy causes silent myocardial ischemia, characterized by loss of pain perception during myocardial ischemia, which is a major cause of sudden cardiac death in diabetes mellitus (DM). Despite its clinical importance, the mechanisms underlying the control and regulation of cardiac innervation remain poorly understood.We found that cardiac innervation is determined by the balance between neural chemoattractants and chemorepellents within the heart. Nerve growth factor (NGF), a potent chemoattractant, is induced by endothelin-1 upregulation during development and is highly expressed in cardiomyocytes. By comparison, Sema3a, a neural chemorepellent, is highly expressed in the subendocardium of early stage embryos, and is suppressed during development. The balance of expression between NGF and Seme3a leads to epicardial-to-endocardial transmural sympathetic innervation patterning. We also found that downregulation of cardiac NGF leads to diabetic neuropathy, and that NGF supplementation rescues silent myocardial ischemia in DM. Cardiac innervation patterning is disrupted in Sema3a-deficient and Sema3a-overexpressing mice, leading to sudden death or lethal arrhythmias. The present review focuses on the regulatory mechanisms underlying cardiac innervation and the critical role of these processes in cardiac performance. PMID: 21037846 [PubMed - in process] | | | | | | | | | | | | | | | | | | | | | | | | | Development and implementation of a technical and didactical training program for student tutors in the dissection course. Ann Anat. 2010 Sep 17; Authors: Shiozawa T, Hirt B, Celebi N, Baur F, Weyrich P, Lammerding-Köppel M BACKGROUND: Student tutors have a long tradition in gross anatomy instruction. However, the full potential of the tutors is generally not tapped, since little attention is paid to their technical and didactical training. The aim of this paper is to report a systematic approach to the development, didactic reasoning and implementation of a curriculum for training student tutors in gross anatomy. METHODS: The training program was developed using the six-step approach of Kern's curriculum development model. For needs assessment, the literature research was amended by a survey among the 1st and 2nd year students of the dissection course (n=167) and two independent 90min focus group interviews with the tutors who supervised these students (n=15). Protocols were transcribed and analyzed by margin coding. The training curriculum was setup on the basis of these data. RESULTS: Corresponding to the literature, the students want student tutors with good teaching competence as well as adequate content knowledge and technical competence. Supporting that, the tutors request a training program enhancing their didactic skills as well as their knowledge of content and working using relevant methods. Thus, a combined didactic and professional training program has been developed. Six professional and 11 didactic learning objectives were defined. A 3 weeks training curriculum was implemented, using microteaching and group exercises for didactics and active dissection for technical training. Both parts were interlocked on a contextual and practical level. CONCLUSION: Our focus group analyses revealed that a specific training program for student tutors in the dissection course is necessary. We describe a feasible task-oriented training curriculum combining didactic and professional objectives. PMID: 21036570 [PubMed - as supplied by publisher] | | | | | | | | | | | | | | | | | | | | | | | | | Does a combined technical and didactical training program improve the acceptance of student tutors in the dissection course? A prospective controlled randomized study. Ann Anat. 2010 Oct 29; Authors: Shiozawa T, Hirt B, Celebi N, Werner A, Weyrich P, Lammerding-Koeppel M BACKGROUND: Student tutors in the dissection course are expected to meet high demands on their job. We developed a combined technical and didactical training on the basis of literature review and needs assessment. The three-week training program comprised dissection as well as presentation techniques, group dynamics and activating teaching methods. A randomized, controlled, single-blind study was set up to test whether there is a difference between the tutee's perception of the tutor competences, comparing trained and untrained tutors. METHODS: A total of 10 trained and 10 untrained tutors (control group) were enlisted in the study. The acceptance of the training program was measured with a questionnaire (11 items, 5-point Likert scale) where the tutees rated the competences of the tutors. The tutees were assigned randomly to their tutor and blinded to his/her training. RESULTS: The tutees assessed the trained tutors better in all categories compared to the untrained tutors. A significantly better score (p<0.05) was stated for the categories "conveying basic dissection techniques" (4.31±0.86 vs. 3.89±1.05), "positive group atmosphere" (4.69±0.73 vs. 4.44±0.88), "learning support" (4.24±1.03 vs. 3.79±1.16) and "visualisation" (3.99±1.11 vs. 3.56±1.17). In self-assessment, the trained tutors rated themselves significantly better after the training compared to before in all categories. CONCLUSION: The specific training curriculum for tutors in the dissection course, focusing on the improvement of content knowledge, technical and didactical competencies, is well accepted by the tutees and tutors. PMID: 21036569 [PubMed - as supplied by publisher] | | | | | | | | | | | | | | | | | | | | | | | | | The advantages of hair follicle pluripotent stem cells over embryonic stem cells and induced pluripotent stem cells for regenerative medicine. J Dermatol Sci. 2010 Oct 1; Authors: Amoh Y, Katsuoka K, Hoffman RM Multipotent adult stem cells have many potential therapeutic applications. Our recent findings suggest that hair follicles are a promising source of easily accessible multipotent stem cells. Stem cells in the hair follicle area express the neural stem cell marker nestin, suggesting that hair-follicle stem cells and neural stem cells have common features. Nestin-expressing hair follicle stem cells can form neurons and other cell types, and thus adult hair follicle stem cells could have important therapeutic applications, particularly for neurologic diseases. Transplanted hair follicle stem cells promote the functional recovery of injured peripheral nerve and spinal cord. Recent findings suggest that direct transplantation of hair-follicle stem cells without culture can promote nerve repair, which makes them potentially clinically practical. Human hair follicle stem cells as well as mouse hair follicle stem cells promote nerve repair and can be applied to test the hypothesis that human hair follicle stem cells can provide a readily available source of neurologically therapeutic stem cells. The use of hair follicle stem cells for nerve regeneration overcomes critical problems of embryonic stem cells or induced pluripotent stem cells in that the hair follicle stem cells are multipotent, readily accessible, non-oncogenic, and are not associated with ethical issues. PMID: 21036545 [PubMed - as supplied by publisher] | | | | | | | | | | | | | | | | | | | | | | | | | A simplified procedure to reconstitute hair producing skin. Tissue Eng Part C Methods. 2010 Oct 29; Authors: Lee L, Jiang T, Garner W, Chuong CM One of the major objectives of tissue engineering is to reconstitute skin from stem cells. This requires multi-potent skin stem cells and the ability to guide these cells to form a piece of skin with proper architecture and skin appendages. Based on previous progress, we develop a simplified procedure that can be useful for large-scale screening of factors that can modulate the hair formation ability of candidate cells. Newborn mouse cells are used. Dissociated epidermal and dermal cells in high density suspension are allowed to reconstitute in vitro to generate its own matrix, or seeded into a scaffold-like matrix already used clinically. These cells self-organize and form a reconstituted skin with proper proportions and topological organization of different components. Large numbers of hair follicles form. The cellular and molecular events are characterized, showing a distinct but parallel morphogenetic process compared to those occurring in embryonic development. The formed hair follicles can cycle and regenerate and the reconstituted skin can heal after injury. The skins are in good condition one year after transplant. This procedure enables flexible size and shape of the reconstituted skin, so that clinical applications can be envisioned for the future. PMID: 21034159 [PubMed - as supplied by publisher] | | | | | | | | | | | | | | | | | | | | | | | | | E phage gene transfection enhances sensitivity of lung and colon cancer cells to chemotherapeutic agents. Int J Oncol. 2010 Dec;37(6):1503-14 Authors: Rama AR, Prados J, Melguizo C, Ortiz R, Alvarez PJ, Rodríguez-Serrano F, Hita F, Ramos JL, Burgos M, Aranega A The E gene from ΦX174 encodes a membrane protein with a toxic domain that leads to a decrease in the tumour cell growth rate. With the aim of improving the antitumour effect on lung and colon cancer cells of the currently used chemotherapeutic drugs such as gemcitabine, carboplatin and paclitaxel, and 5-fluorouracil (5FU) plus folinic acid (FA) with irinotecan or oxaliplatine, we investigated a new combined therapy using these drugs associated to the transfection of E gene. Our results showed that E gene was able to decrease proliferation rate in A-549 and T-84 cells by inducing apoptotic the mitochondrial pathway. Significantly greater inhibition of proliferation was obtained using drugs in combination with E gene in comparison to single-agent treatments or controls. E gene combined with paclitaxel had the greatest effect on A-549 cells and combined with 5FU/FA/oxaliplatin on T-84 cells. Antitumour mechanisms of the chemotherapeutic drugs were enhanced by E gene, which itself has direct oncolytic effects inducing A-549 and T-84 apoptosis. Our in vitro results indicate that the combined therapy of E gene and cytotoxic drugs may be of potential therapeutic value as a new strategy for patients with advanced lung and colon cancer. PMID: 21042719 [PubMed - in process] | | | | | | | | | |  | |  | |  |
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