| Induction of chondrogenesis from human embryonic stem cells without embryoid body formation by bone morphogenetic protein 7 and transforming growth factor beta1.
December 2, 2009 at 7:32 am
|
| | Induction of chondrogenesis from human embryonic stem cells without embryoid body formation by bone morphogenetic protein 7 and transforming growth factor beta1. Arthritis Rheum. 2009 Nov 30;60(12):3686-3692 Authors: Nakagawa T, Lee SY, Reddi AH OBJECTIVE: Human embryonic stem cells (ESCs) provide an unlimited supply of pluripotent cells for articular cartilage tissue engineering and regenerative medicine applications. Articular cartilage is an avascular tissue with precise polarity and organization comprising 3 distinct functional zones: surface, middle, and deep. To date, attempts at differentiating human ESCs into articular chondrocytes have been unsuccessful. The majority of studies have focused on chondrogenic (but not specifically articular cartilage) differentiation. Furthermore, previous investigations of induction of chondrogenesis by human ESCs required embryoid body formation; however, embryoid body formation often results in heterogeneous differentiation. The present study was undertaken to determine the in vitro chondrogenic potential of bone morphogenetic protein 7 (BMP-7) and transforming growth factor beta1 (TGFbeta1)-induced human ESC differentiation toward the articular cartilage phenotype. METHODS: Dissociated single human ESCs were cultured and passaged on a gelatin-coated flask. The human ESCs were cultured as an aggregate in a pellet culture system for 14 days in basal chondrogenic medium (CM), CM with TGFbeta1, CM with BMP-7, or CM with both TGFbeta1 and BMP-7. RESULTS: The size and wet weight of the cartilage pellets and glycosaminoglycan levels increased, with the smallest, intermediate, and greatest increases, respectively, observed with CM plus TGFbeta1 treatment, CM plus BMP-7 treatment, and CM plus TGFbeta1 and BMP-7 treatment (compared with CM treatment alone). The largest size and highest weight of the pellet was in the group in which TGFbeta1 and BMP-7 were added to the medium. However, expression of the genes for cartilage-specific aggrecan and type II collagen II, as assessed by determination of messenger RNA levels, was highest in the BMP-7-treated group. Superficial zone protein (SZP)/lubricin, a marker of the superficial zone articular chondrocyte, was not detectable under identical culture conditions. CONCLUSION: These results demonstrate an efficient and reproducible model system of human ESC-induced chondrogenesis, using a novel direct plating method in which intervening embryoid body formation does not occur. Further work is needed for optimization of conditions to obtain the articular cartilage phenotype that includes the superficial zone marker as demonstrated by SZP/lubricin synthesis. PMID: 19950276 [PubMed - as supplied by publisher] |
| Bone marrow mesenchymal stem cells.
December 2, 2009 at 7:32 am
|
| | Bone marrow mesenchymal stem cells. J Cell Biochem. 2009 Nov 30; Authors: Ohishi M, Schipani E Following the identification of bone marrow multipotent cells that could adhere to plastic and differentiate along numerous mesenchymal lineages in vitro, a considerable effort has been invested in characterizing and expanding these cells, which are now called "mesenchymal stem cells" (MSCs), in vitro. Over the years, numerous lines of evidence have been provided in support of their plasticity, their extraordinary immunomodulatory properties, their potential use for tissue engineering purposes, as well as their ability to be recruited to sites of injury, where they might contribute a "natural in vivo system for tissue repair." Moreover, some studies have attempted the characterization of their cell-surface specific antigens and of their anatomical location in vivo. Lastly, it has been shown that similar cells could be also isolated from organs other than the bone marrow. Despite this impressive body of investigations, numerous questions related to the developmental origin of these cells, their proposed pluripotency, and their role in bone modeling and remodeling and tissue repair in vivo are still largely unanswered. In addition, both a systematic phenotypic in vivo characterization of the MSC population and the development of a reproducible and faithful in vivo assay that would test the ability of MSCs to self-renew, proliferate, and differentiate in vivo are just beginning. This brief review summarizes the current knowledge in the field of study of MSCs and the outstanding questions. J. Cell. Biochem. (c) 2009 Wiley-Liss, Inc. PMID: 19950205 [PubMed - as supplied by publisher] |
| [Embryonic stem cells - a scientific by-product of the assisted reproduction technology?]
December 2, 2009 at 7:32 am
|
| | [Embryonic stem cells - a scientific by-product of the assisted reproduction technology?] Ther Umsch. 2009 Dec;66(12):839-45 Authors: Sterthaus O, Zhang H, De Geyter C The differentiation potential of embryonic stem (ES) cells seems to be higher when compared to adult stem cells, which mainly differentiate into certain tissue types only. ES cells have the potential to play an important role in regenerative medicine as demonstrated with murine ES cells. However, with human embryonic stem cells (hESC) several obstacles still have to be overcome, when these are to be used in clinical applications. The expansion of hESC, safety issues as well as the immune-tolerance after transplantation are all problems that still have to be solved. Since 2005 the derivation of hESC lines from supernumerous embryos has become permitted in Switzerland, albeit under strictly restrictive guidelines. In 2008 the Basler hESC laboratory was successful in derivating the first hESC line with a normal chromosome complement in Switzerland (CHES2). Now, new applications allow the personalized establishment of immune-tolerant stem cells, which lead to the replacement of therapeutic cloning by induced pluripotent stem cells (iPS). PMID: 19950064 [PubMed - in process] |
| Is stem cell-based therapy going on or out for cardiac disease?
December 2, 2009 at 7:32 am
|
| | Is stem cell-based therapy going on or out for cardiac disease? Korean Circ J. 2009 Mar;39(3):87-92 Authors: Byun KH, Kim SW Acute myocardial infarction and subsequent heart failure are leading causes of death worldwide. Stem cell-based therapies have improved cardiac function in recent clinical trials, but cardiomyocyte regeneration has not been demonstrated in human hearts. Angiogenesis and restoration of cardiac perfusion have been successfully performed using bone marrow derived stem cells and other adult stem cells. Resident cardiac stem cells are known to differentiate into multiple heart cell types, including cardiomyocytes. Furthermore, induced pluripotent stem cells are a focus of research due to the great potential for customized stem cell therapy. PMID: 19949592 [PubMed - in process] |
| Irving Weissman: Working for regenerative medicine.
December 2, 2009 at 7:32 am
|
| | Irving Weissman: Working for regenerative medicine. J Cell Biol. 2009 Nov 2;187(3):316-7 Authors: Lebrasseur N PMID: 19948474 [PubMed - in process] |
| Controlling the in vitro differentiation of embryonic stem cells for myocardial tissue engineering applications.
December 2, 2009 at 7:32 am
|
| | Controlling the in vitro differentiation of embryonic stem cells for myocardial tissue engineering applications. Cell Biol Int. 2009 Sep 15; Authors: Ou DB, Chen R, Liu XT, Guo JJ, Wang HT, Zheng QS We studied the differentiation of embryonic stem cells (ESCs) and developed a novel protocol for generating functional cardiomyocytes (CMs) from ESCs by co-culturing these with live cardiac cells. We then evaluated the structural and functional properties of these ESC-derived CMs (ESCMs). An acellular matrix obtained from rabbit heart tissues was used as a scaffold. Then ESCMs were seeded onto the acellular matrix for preliminary tissue engineering applications. We found that by mimicking the cardiac microenvironment, the percentage of beating embryoid bodies (EBs) was much higher and the homogeneity of EBs were significantly improved over that seen in the control group (p<0.001). ESCMs in EBs acquired almost the same structural and functional properties as typical CMs. After implantation, the cells in the EBs rapidly grew and expanded in the extracellular matrix. These results indicate that the differentiation of ESCs can be controlled in a cardiac mimicking microenvironment and that ESCs can be used as an ideal cell source for large-scale tissue engineering applications for the procurement of cardiac muscle. PMID: 19947942 [PubMed - as supplied by publisher] |
| Characterization of MSCs from human placental decidua basalis in hypoxia and serum deprivation.
December 2, 2009 at 7:32 am
|
| | Characterization of MSCs from human placental decidua basalis in hypoxia and serum deprivation. Cell Biol Int. 2009 Oct 26; Authors: Huang YC, Yang ZM, Jiang NG, Chen XH, Li XQ, Tan MY, Zhou KP, Tang L, Xie HQ, Deng L Recently we reported that human placental decidua basalis is an excellent source of mesenchymal stem cells (PDB-MSCs), meanwhile, PDB-MSCs could survive under hypoxia and serum deprivation. Herein we investigated the proliferation, clonogentic efficiency, phenotypes, metabolic activity and cytokines secretion of PDB-MSCs in hypoxia and serum deprivation. PDB-MSCs were cultured in four groups: normoxia (20%O2) and complete medium (10%FBS+ DMEM-HG), hypoxia and complete medium, normoxia and serum deprivation (0%FBS), and hypoxia and serum deprivation. After 96 hours of culture in above groups, PDB-MSCs maintain the phenotypes stably. Interestingly, hypoxia notably enhanced the proliferation, colony forming potential and lactate/glucose ratio in complete medium, but suppressed the secretion of BMP-2 and bFGF while did not change the quantity of VEGF and bFGF in serum deprivation. Although PDB-MSCs grew slowly and seldom formed a colony unit in hypoxia and serum, they possessed a moderate metabolism. In conclusion, our results indicate that PDB-MSCs appear to be promising seed cells for ischemia related tissue engineering. PMID: 19947920 [PubMed - as supplied by publisher] |
| Review of NANOBIO 2009 - Tissue engineering in India.
December 2, 2009 at 7:32 am
|
| | Review of NANOBIO 2009 - Tissue engineering in India. Tissue Eng Part A. 2009 Nov 30; Authors: Nair S Review of Nanobio conference 2009. PMID: 19947853 [PubMed - as supplied by publisher] |
| Toward cell therapy using placenta-derived cells: Disease mechanisms, cell biology, preclinical studies, and regulatory aspects at the round table.
December 2, 2009 at 7:32 am
|
| | Toward cell therapy using placenta-derived cells: Disease mechanisms, cell biology, preclinical studies, and regulatory aspects at the round table. Stem Cells Dev. 2009 Nov 30; Authors: Parolini O, Alviano F, Bergwerf I, Boraschi D, De Bari C, De Waele P, Dominici M, Evangelista M, Falk W, Hennerbichler S, Hess DA, Lanzoni G, Liu B, Marongiu F, Mc Guckin C, Mohr S, Nolli ML, Ofir R, Ponsaerts P, Romagnoli L, Solomon A, Soncini M, Strom S, Surbek D, Venkatachalam S, Wolbank S, Zeisberger S, Zeitlin A, Zisch A, Borlongan CV Among the many cell types which may prove useful to regenerative medicine, mounting evidence suggests that human term placenta-derived cells will join the list of significant contributors. In making new cell therapy-based strategies a clinical reality, it is fundamental that no a priori claims are made regarding which cell source is preferable for a particular therapeutic application. Rather, ongoing comparisons of the potentiality and characteristics of cells from different sources should be made to promote constant improvement in cell therapies, and such comparisons will likely show that individually-tailored cells can address disease-specific clinical needs. The principle underlying such an approach is resistance to the notion that comprehensive characterization of any cell type has been achieved, neither in terms of phenotype nor risks-to-benefits ratio. Tailoring cell therapy approaches to specific conditions also requires an understanding of basic disease mechanisms and close collaboration between translational researchers and clinicians, to identify current needs and shortcomings in existing treatments. To this end, the international workshop entitled "Placenta-derived stem cells for treatment of inflammatory diseases: moving toward clinical application" was held in Brescia, Italy, in March 2009, and aimed to harness an understanding of basic inflammatory mechanisms inherent in human diseases with updated findings regarding biological and therapeutic properties of human placenta-derived cells, with particular emphasis on their potential for treating inflammatory diseases. Finally, steps required to allow their future clinical application according to regulatory aspects including good manufacturing practice (GMP) were also considered. In September, 2009, the International Placenta Stem Cell Society (IPLASS) was founded to help strengthen the research network in this field. PMID: 19947828 [PubMed - as supplied by publisher] |
| Injectable Biodegradable Thermosensitive Hydrogel Composite for Orthopedic Tissue Engineering. 1. Preparation and Characterization of Nanohydroxyapatite/Poly(ethylene glycol)-Poly(epsilon-caprolactone)-Poly(ethylene glycol) Hydrogel Nanocomposites.
December 2, 2009 at 7:32 am
|
| | Injectable Biodegradable Thermosensitive Hydrogel Composite for Orthopedic Tissue Engineering. 1. Preparation and Characterization of Nanohydroxyapatite/Poly(ethylene glycol)-Poly(epsilon-caprolactone)-Poly(ethylene glycol) Hydrogel Nanocomposites. J Phys Chem B. 2009 Nov 30; Authors: Fu S, Guo G, Gong C, Zeng S, Liang H, Luo F, Zhang X, Zhao X, Wei Y, Qian Z In this study, we synthesized a biodegradable triblock copolymer poly(ethylene glycol)-poly(epsilon-caprolactone)-poly(ethylene glycol) (PEG-PCL-PEG, PECE) by ring-opening copolymerization, and nanohydroxyapatite (n-HA) powder was prepared by a hydrothermal precipitation method. The obtained n-HA was incorporated into the PECE matrix to prepare injectable thermosensitive hydrogel nanocomposites. (1)H NMR, FT-IR, XRD, DSC, and TEM were used to investigate the properties of PECE copolymer and n-HA/PECE nanocomposites. The rheological measurements for n-HA/PECE nanocomposites revealed that the gelation temperature was approximately 36 degrees C. The sol-gel-sol transition behavior and phase transition diagrams were recorded through a test tube inverting method. The results showed that n-HA/PECE nanocomposites still had thermoresponsivity like that of PECE thermosensitive hydrogel. The morphology of the nanocomposites was observed by SEM; the results showed that the nanocomposites had a 3D network structure. In addition, the effects of n-HA contents on the properties of n-HA/PECE nanocomposites are also discussed in the paper. From the results, n-HA/PECE hydrogel is believed to be promising for injectable orthopedic tissue engineering due to its good thermosensitivity and injectability. PMID: 19947637 [PubMed - as supplied by publisher] | | | 
|
No comments:
Post a Comment