| Duke/Singapore scientists find new way to classify gastric cancers
October 1, 2009 at 10:05 pm
|
| |
| International Rett Syndrome Foundation awards $2M for cutting-edge Rett syndrome research
October 1, 2009 at 5:47 pm
|
| |
| Retinal rescue: Cells derived from human embryonic stem cells reverse retinal degeneration
October 1, 2009 at 1:46 pm
|
| |
| It's in the bank: Human cord blood reprogrammed into embryonic-like stem cells
October 1, 2009 at 1:46 pm
|
| |
| Sangamo BioSciences Announces Research Collaboration With UCLA in Human Stem Cells Selected to Receive Clinical Research Award
October 1, 2009 at 7:45 am
|
| |
| Translating stem cell therapy to the clinic: déjà vu all over again.
October 1, 2009 at 7:24 am
|
| | Translating stem cell therapy to the clinic: déjà vu all over again. Mol Ther. 2009 Oct;17(10):1659-60 Authors: Crystal RG PMID: 19789557 [PubMed - in process] |
| The inherent differentiation program of short term hematopoietic repopulating cells changes during human ontogeny.
October 1, 2009 at 7:24 am
|
| | The inherent differentiation program of short term hematopoietic repopulating cells changes during human ontogeny. Stem Cells Dev. 2009 Sep 29; Authors: Tacke M, Ball CR, Schmidt M, Klingenberg S, Maurer B, Fessler S, Eaves C, von Kalle C, Glimm H Human umbilical cord blood (CB) could be an attractive source of hematopoietic repopulating cells for clinical stem cell therapy because of its accessibility and low propensity for unwanted immune reaction against the host. However, cord blood recipients suffer from severely delayed and often chronically deficient platelet recovery of unknown cause. Here we show that human short term repopulating cells (STRC), which predominantly carry early hematopoietic reconstitution after transplantation, display an intrinsically fixed differentiation program in vivo which changes during ontogeny. Compared to adult sources of hematopoietic cells, cord blood myeloid-restricted STRC-M showed a markedly reduced megakaryocytic and erythroid cell output in the quantitative xenotransplantation of human short-term hematopoiesis in NOD/SCID-ss2m<sup>-/-</sup> mice. This output in vivo was not altered by pre-treating cord blood cells before transplantation with growth factors that effectively stimulate megakaryocytopoiesis in vitro. Moreover, injecting mice with granulocyte colony-stimulating factor did not affect the differentiation of human STRC. These findings demonstrate that the differentiation capacity of human short term repopulating cells is developmentally regulated by mechanisms inaccessible to currently available hematopoietic growth factors, and explain why thrombopoiesis is deficient in clinical cord blood transplantation. PMID: 19788397 [PubMed - as supplied by publisher] |
| Effects of basic fibroblast growth factor on the development of the stem cell properties of human dental pulp cells.
October 1, 2009 at 6:53 am
|
| | Effects of basic fibroblast growth factor on the development of the stem cell properties of human dental pulp cells. Arch Histol Cytol. 2009 Mar;72(1):51-64 Authors: Morito A, Kida Y, Suzuki K, Inoue K, Kuroda N, Gomi K, Arai T, Sato T We isolated adherent fibroblastic cells after collagenase and dispase treatment of human dental pulp. When human dental pulp cells (hDPCs) were cultured in the presence of basic fibroblast growth factor (bFGF), the ratio of hDPCs in the S-phase was significantly higher in comparison with incubation without bFGF. The ratio of hDPCs expressing STRO-1 as a marker of stem cell populations increased approximately eightfold in the presence of bFGF as opposed to that in the absence of bFGF. We demonstrated the characterization and distinctiveness of the hDPCs and showed that, when cultured with the medium containing serum and bFGF, they were highly proliferative and capable of differentiating in vitro into osteoblasts, chondrocytes, and adipocytes. Furthermore, the in vitro differentiation was confirmed at both the protein and gene expression levels. Transplantation of hDPCs -- expanded ex vivo in the presence of bFGF into immunocompromised mice -- revealed the formation of bone, cartilage, and adipose tissue. The donor hDPC-derived cells were labeled in the bone tissues located near the PLGA in the subcutaneous tissues of recipient mice using a human-specific Alu probe. When cultured with a serum-free medium containing bFGF, the hDPCs strongly expressed STRO-1 immunoreactive products and sustained self-renewal, and thus were almost identical in differentiation potential and proliferation activity to hDPCs cultured with the medium containing serum and bFGF. The present results suggest that the hDPCs cultured in the presence of bFGF irrespective of the presence or absence of the bovine serum are rich in mesenchymal stem cells or progenitor cells and useful for cell-based therapies to treat dental diseases. PMID: 19789412 [PubMed - in process] |
| FUNCTIONAL DIFFERENCES BETWEEN MESENCHYMAL STEM CELL POPULATIONS ARE REFLECTED BY THEIR TRANSCRIPTOME.
October 1, 2009 at 6:53 am
|
| | FUNCTIONAL DIFFERENCES BETWEEN MESENCHYMAL STEM CELL POPULATIONS ARE REFLECTED BY THEIR TRANSCRIPTOME. Stem Cells Dev. 2009 Sep 29; Authors: Jansen BJ, Gilissen C, Roelofs H, Schaap-Oziemlak A, Veltman J, Raymakers RA, Jansen J, Kögler G, Figdor CG, Torensma R, Adema GJ Stem cells are widely studied to enable their use in tissue repair. However, differences in function and differentiation potential exist between distinct stem cell populations. Whether those differences are due to donor variation, cell culture or intrinsic properties remains elusive. Therefore, we compared three cell lines isolated from three different niches using the Affymetrix Exon Array platform: the cord blood-derived neonatal unrestricted somatic stem cell (USSC), adult bone marrow-derived mesenchymal stem cells (BM-MSC) and adult adipose tissue-derived stem cells (AdAS). While donor variation was minimal, large differences between stem cells of different origin were detected. BM-MSC and AdAS, outwardly similar, are more closely related to each other than to USSC. Interestingly, USSC expressed genes involved in the cell cycle and in neurogenesis, consistent with their reported neuronal differentiation capacity. The BM-MSC signature indicates that they are primed towards developmental processes of tissues and organs derived from the mesoderm and endoderm. Remarkably, AdAS appear to be highly enriched in immune-related genes. Together, the data suggest that the different mesenchymal stem cell types have distinct gene expression profiles, reflecting their origin and differentiation potential. Furthermore, these differences indicate a demand for effective differentiation protocols tailored to each stem cell type. PMID: 19788395 [PubMed - as supplied by publisher] |
| Equine adipose-tissue derived mesenchymal stem cells and platelet concentrates: their association in vitro and in vivo.
October 1, 2009 at 6:53 am
|
| | Equine adipose-tissue derived mesenchymal stem cells and platelet concentrates: their association in vitro and in vivo. Vet Res Commun. 2008 Sep;32 Suppl 1:S51-5 Authors: Del Bue M, Riccò S, Ramoni R, Conti V, Gnudi G, Grolli S Equine mesenchymal stem cells (MSC) are of particular interest both for basic research and for the therapeutic approach to musculoskeletal diseases in the horse. Their multilineage differentiation potential gives them the capability to contribute to the repair of tendon, ligament and bone damage. MSCs are also considered a promising therapeutic aid in allogeneic cell transplantation, since they show low immunogenicity and immunomodulating functions.Adipose tissue-derived adult equine stem cells (AdMSC) can be isolated, expanded in vitro and then inoculated into the damaged tissue, eventually in the presence of a biological scaffold. Here we report our preliminary experience with adipose-derived mesenchymal stem cells in allogeneic cell-therapy of tendonitis in the horse. MSCs, derived from visceral adipose tissue, were grown in the presence of autologous platelet lysate and characterized for their differentiation and growth potential. Expanded AdMSC were inoculated into the damaged tendon after their dispersion in activated platelet-rich plasma (PRP), a biological scaffold that plays an important role in maintaining cells in defect sites and contributes to tissue healing. Fourteen out of sixteen treated horses showed a functional recovery and were able to return to their normal activity. PMID: 18683070 [PubMed - indexed for MEDLINE] |
| [Possibilities and limits in tissue engineering of the anterior cruciate ligament.]
October 1, 2009 at 6:38 am
|
| | [Possibilities and limits in tissue engineering of the anterior cruciate ligament.] Orthopade. 2009 Oct 1; Authors: Ignatius A, Dürselen L Although current concepts of cruciate ligament reconstruction using tendon transplants provide midterm knee joint stabilization, a single-bundle or double-bundle tendon cannot adequately restore the complex three-dimensional structure of the anterior cruciate ligament. Therefore, researchers are attempting to develop alternatives using tissue engineering technology. The basic principle includes seeding of suitable cells on a resorbable carrier construct, in vitro biological and mechanical stimulation to generate a ligament-like extracellular matrix, and subsequent implantation as a cruciate ligament bioprosthesis. Several natural and synthetic materials have proven to be suitable as cell carriers; however, most of these exhibit inadequate tensile strength as well as minor fatigue properties, making an additional load carrier necessary. In principle, research has shown that tissue engineering technology is capable of generating a construct with a ligament-like extracellular matrix. However, the step from basic research to clinical application has not yet been taken. PMID: 19789854 [PubMed - as supplied by publisher] |
| A Novel Route in Bone Tissue Engineering: Magnetic Biomimetic Scaffolds.
October 1, 2009 at 6:38 am
|
| | A Novel Route in Bone Tissue Engineering: Magnetic Biomimetic Scaffolds. Acta Biomater. 2009 Sep 26; Authors: Bock N, Riminucci A, Dionigi C, Russo A, Tampieri A, Landi E, Goranov VA, Marcacci M, Dediu V In the past years, the interest in tissue engineering and its solutions have considerably increased. In particular, scaffolds have become fundamental tools in bone graft substitution and are used in combination with a variety of bio-agents. A long standing problem however, in the use of these conventional scaffolds, lies in the impossibility of re-loading the scaffold with the bio-agents after implantation. This work introduces the magnetic scaffold as a conceptually new solution. The magnetic scaffold is able via magnetic driving to attract and take up in vivo growth factors, stem cells or other bio-agents bound to magnetic particles. We succeeded to develop a simple and inexpensive technique able to transform standard commercial scaffolds made of hydroxyapatite and collagen in magnetic scaffolds. This innovative process involves dip-coating of the scaffolds in aqueous ferrofluids containing iron oxide nanoparticles coated with various biopolymers. After dip-coating, the nanoparticles are integrated into the structure of the scaffolds providing the latter with magnetization values as high as 15 emu/g at 10 kOe. This values are suitable to generate magnetic gradients enabling magnetic guiding in the vicinity and inside the scaffold. The magnetic scaffolds do not suffer from any structural damage during the process maintaining their specific porosity and shape. Moreover, they do not release magnetic particles under a constant flow of simulated body fluids over a period of eight days. Finally, preliminary studies indicate the ability of the magnetic scaffolds to support adhesion and proliferation of human bone marrow stem cells in vitro. Hence this new type of scaffold is a valuable candidate for tissue engineering applications featuring a novel magnetic guiding option. PMID: 19788946 [PubMed - as supplied by publisher] |
| Chitosan/ polyester - based scaffolds for cartilage tissue engineering: assessment of extracellular matrix formation.
October 1, 2009 at 6:38 am
|
| | Chitosan/ polyester - based scaffolds for cartilage tissue engineering: assessment of extracellular matrix formation. Acta Biomater. 2009 Sep 26; Authors: Silva ML, Crawford A, Mundy JM, Correlo VM, Sol P, Bhattacharya M, Hatton PV, Reis RL, Neves NM Natural-based polymers have been extensively used in scaffolds production for cartilage tissue engineering. The present work aims at evaluating and characterizing extracellular matrix (ECM) formation in two types of chitosan-based scaffolds, using bovine articular chondrocytes (BAC). The influence of these scaffolds porosity, as well as pore size and geometry in cartilagineous tissue formation was studied. The effect of stirred conditions on ECM formation was also assessed. Chitosan-Poly (Butylene Succinate) (PBS) scaffolds where produced by compression moulding and salt leaching, using a blend of 50% of each material. Different porosities and pore sizes structures were obtained. BAC were seeded onto CPBS scaffolds using spinner flasks. After that period, constructs were transferred to the incubator, where half were cultured under stirred conditions, and the other half under static conditions, during 4 weeks. Constructs were characterized by scanning electron microscopy, histology procedures, immunolocalisation of collagen type I and collagen type II and dimethylmethylene blue (DMB) assay for glycosaminoglycans (GAG) quantification. Both materials showed good affinity for cell attachment. Cells colonized the entire scaffolds and were able to produce ECM. Large pores with random geometry improved proteoglycans and collagen type II production. However, that structure has the opposite effect on GAG production. Stirred culture conditions indicate to enhance GAG production, in both types of scaffolds. PMID: 19788942 [PubMed - as supplied by publisher] |
| Inhibition of hepatic stellate cells proliferation by mesenchymal stem cells and the possible mechanisms.
October 1, 2009 at 6:38 am
|
| | Inhibition of hepatic stellate cells proliferation by mesenchymal stem cells and the possible mechanisms. Hepatol Res. 2009 Sep 25; Authors: Wang J, Bian C, Liao L, Zhu Y, Li J, Zeng L, Zhao RC Aim: During fibrosis, hepatic stellate cells (HSCs) undergo a complex activation process characterized by increased proliferation and extracellular matrix deposition. Previous studies have suggested that mesenchymal stem cells (MSCs) may ameliorate fibrogenesis and represent a promising strategy for cell therapy. However, the underlying mechanisms are not fully understood. Methods: Hepatic stellate cells were treated with or without MSCs. Then cell proliferation and cell cycle were analyzed. Production of soluble factors by MSCs and its relation with cell proliferation suppression was evaluated by transwell co-culture and RNA interference. Effects of MSCs on the gene expression of collagen were also evaluated. Results: MSCs induced G(0)/G(1) arrest of HSCs growth partly through secreting soluble factors TGF-beta3 and HGF, which resulted in up-regulation of p21(Cip1) and p27(Kip1) expression and down-regulation of cyclinD1. MSCs inhibited the phosphorylation of extracellular signal-regulated kinase (ERK) 1/2 and reduced gene expression of collagen type I and III. MSCs did not reverse the proliferation and collagen type I gene expression of HSCs provoked by PDGF. Conclusions: The growth inhibition of HSCs induced by MSCs through an arrest in the G(0)/G(1) phase of the cell cycle is partially mediated by secretion of TGF-beta3 and HGF. MSCs inhibit HSCs activation through decreasing phosphorylation of extracellular signal-regulated kinase (ERK) 1/2. These results further support MSCs may be used as a novel therapy for treating fibrotic diseases in human. PMID: 19788697 [PubMed - as supplied by publisher] |
| Evaluation of Methylcellulose and Dimethylsulfoxide as the Cryoprotectants in a Serum Free Freezing Media for Cryopreservation of Adipose Derived Adult Stem Cells.
October 1, 2009 at 6:38 am
|
| | Evaluation of Methylcellulose and Dimethylsulfoxide as the Cryoprotectants in a Serum Free Freezing Media for Cryopreservation of Adipose Derived Adult Stem Cells. Stem Cells Dev. 2009 Sep 29; Authors: Thirumala S, Gimble J, Devireddy R Developing effective techniques for the cryopreservation of human Adipose Derived Adult Stem Cells (ASCs) could increase the usefulness of these cells in tissue engineering and regenerative medicine. To this end we investigated the post-freeze/thaw viability and apoptotic behavior of Passage 1 (P1) adult stem cells (ASCs) in eleven different media: (i) the traditional media containing Dulbecco's Modified Eagle Medium (DMEM) with 80% Fetal Calf Serum (FCS) and 10% dimethyl sulfoxide (DMSO), (ii) DMEM with 80% Human Serum (HS) and 10% DMSO, (iii) DMEM with 1% methyl cellulose (MC) and 10% of either HS or FCS or DMSO and (iv) DMEM with 0, 2, 4, 6, 8 or 10% DMSO. Approximately 1 ml (106 cells/ml) of P1 ASCs were frozen over night in a -80 C freezer and stored in liquid nitrogen for two weeks before being rapidly thawed in a 37 C water bath (1 to 2 minutes of agitation), re-suspended in culture media and seeded in separate wells of a 6-well plate for a 24 h incubation period at 37 C. After 24 h, the thawed samples were analyzed by brightfield microscopy and flow cytometry. The results suggest that the absence of DMSO (and the presence of MC) significantly increases the fraction of apoptotic and/or necrotic ASCs. However, the % of viable cells obtained with 2% DMSO and DMEM was comparable with that obtained in freezing media with 10% DMSO and 80% serum (HS or FCS), i.e. ~84+/-5% and ~83+/-8%, respectively. Adipogenic and osteogenic differentiation behavior of the frozen thawed cells was also assessed using histochemical staining. Our results suggest that post-thaw ASC viability, adipogenic and osteogenic differentiability can be maintained even when they are frozen in the absence of serum but with a minimal concentration of 2% DMSO in DMEM. PMID: 19788372 [PubMed - as supplied by publisher] |
| Equine adipose-tissue derived mesenchymal stem cells and platelet concentrates: their association in vitro and in vivo.
October 1, 2009 at 6:38 am
|
| | Equine adipose-tissue derived mesenchymal stem cells and platelet concentrates: their association in vitro and in vivo. Vet Res Commun. 2008 Sep;32 Suppl 1:S51-5 Authors: Del Bue M, Riccò S, Ramoni R, Conti V, Gnudi G, Grolli S Equine mesenchymal stem cells (MSC) are of particular interest both for basic research and for the therapeutic approach to musculoskeletal diseases in the horse. Their multilineage differentiation potential gives them the capability to contribute to the repair of tendon, ligament and bone damage. MSCs are also considered a promising therapeutic aid in allogeneic cell transplantation, since they show low immunogenicity and immunomodulating functions.Adipose tissue-derived adult equine stem cells (AdMSC) can be isolated, expanded in vitro and then inoculated into the damaged tissue, eventually in the presence of a biological scaffold. Here we report our preliminary experience with adipose-derived mesenchymal stem cells in allogeneic cell-therapy of tendonitis in the horse. MSCs, derived from visceral adipose tissue, were grown in the presence of autologous platelet lysate and characterized for their differentiation and growth potential. Expanded AdMSC were inoculated into the damaged tendon after their dispersion in activated platelet-rich plasma (PRP), a biological scaffold that plays an important role in maintaining cells in defect sites and contributes to tissue healing. Fourteen out of sixteen treated horses showed a functional recovery and were able to return to their normal activity. PMID: 18683070 [PubMed - indexed for MEDLINE] |
| [Research of immunogenity of allogenic keratinocytes]
October 1, 2009 at 6:38 am
|
| | [Research of immunogenity of allogenic keratinocytes] Zhongguo Xiu Fu Chong Jian Wai Ke Za Zhi. 2007 Sep;21(9):999-1002 Authors: Bi J, Wu J, Zhu T OBJECTIVE: To observe the change of the immunogenity of keratinocytes when cultured in vitro. METHODS: Health children foreskins were digested by dispase and trypase. The human keratinocytes were cultured in vitro and passaged in succession until the fifth passage. Different passage keratinobytes signed by SP method to show the percentage of langerhans cells and melanocytes. Every passage keratinocytes were respectively mixed with allogenic lymphocytes which isolated from peripheral blood, and then the proliferation degree of allogenic lymphocytes was tested. RESULTS: Keratinocytes were cultured well in K-SFM medium. When keratinocytes conjugated, every passage cells grew like paving stone. After cryopreservation and then rewarming, the survival exceeded 80%. The percentages of langerhans cells and melanocytes in the primary passage were 5.8% and 8.1% respectively. In the 1st passage they were 2.1% and 2.8% respectively. They were not detected in the second passage. The values of cpm were respectively 482.13 +/- 46.61 (primary passage), 362.50 +/- 35.12 (1st passage), 228.38 +/- 51.46 (2nd passage), 171.86 +/- 34.63 (3rd passage), 143.63 +/- 15.95 (4th passage), and 123.25 +/- 14.39 (5th passage), showing statistically significant differences when compared with control (53.67 +/- 8.61) (P < 0.05). There were statistically significant differences between the primary passage, the 1st passage respectively and the other passages (P < 0.05). There were statistically significant differences between the 4th passage, the 5th passage respectively and the 2nd passage (P < 0.05). There was no statistically significant difference between the 2nd passage and the 3rd passages (P > 0.05). There was not statistically significant difference among the 3rd, the 4th and the 5th passages (P > 0.05). CONCLUSION: Allogenic keratinocytes were cultured in vitro and passaged, and their immunogenity gradually decreased. PMID: 17933240 [PubMed - indexed for MEDLINE] |
| [Induced differentiation of mouse embryonic stem cell into endothelial cell in vitro]
October 1, 2009 at 6:38 am
|
| | [Induced differentiation of mouse embryonic stem cell into endothelial cell in vitro] Zhongguo Xiu Fu Chong Jian Wai Ke Za Zhi. 2007 Sep;21(9):994-8 Authors: Xiong J, Liu Z, Liu X OBJECTIVE: To explore an optional condition to induce mouse embryonic stem cell (ESC) to differentiate into endothelial cells so as to provide seed cells for tissue engineered vascular. METHODS: The embryos from one pregnant 12.5-days mouse was harvested to culture the mouse embryonic fibroblasts (MEF). The ESC was reanimated by common method, and used to cultured into embryoid body (EB) in vitro. The EB which was used to induce into endothelial cells was divided into two groups. The EB was cultured in the EB medium with 3 ng/ml transforming growth factor beta1, 50 ng/ml vascular endothelial cell growth factor and 1 micromol/L potent and selective inhibitor of activin receptor-like kinase receptors in experimental group. The EB was cultured in the EB medium in the control group. After 14 days, RT-PCR and immunohistochemistry were used to detect vWF and CD34, to analyze the morphology and type of the differentiated cells from ESC. RESULTS: The primary MEF had a high proliferation activity. At the 3rd day, the fusion rate of MEF was about 90% with a fusiform shape. The cells was fusiform shape and arranged compactly with fullness of nucleus and 2-3 entoblasts. The 3rd-5th generations EB was polygonal with fullness of cytoplasm and 3-4 entoblasts. ESC could maintain undifferentiated state, and the cells unit looked like bird nest with smooth margin; the cells was small at size and strong refractivity with high rate of nuclein and rapid proliferation. At 3 days of drop-culture, EB can seen grossly and at 3 days of suspension, large and transparent EB formed. EB was spread radiately with an intensive adhesion at the 2nd day. In experimental group, many round cells was differentiated around EB from the 4th day to the 7th day, and form tubular structures from the 10th day to the 14th day. The vWF and CD34 were expressed. In control group, EB could not form tubular structures, and the vWF and CD34 were not expressed. CONCLUSION: ESC can differentiate into endothelial cells under some conditions, and form vessel-like structure under condition culture, which can provide sources of seed cells for tissue engineered vessel. PMID: 17933239 [PubMed - indexed for MEDLINE] |
| Adenovirus virion stability and the viral genome: size matters.
October 1, 2009 at 6:09 am
|
| | Adenovirus virion stability and the viral genome: size matters. Mol Ther. 2009 Oct;17(10):1664-6 Authors: Kennedy MA, Parks RJ PMID: 19789561 [PubMed - in process] |
| Chitosan/ polyester - based scaffolds for cartilage tissue engineering: assessment of extracellular matrix formation.
October 1, 2009 at 6:09 am
|
| | Chitosan/ polyester - based scaffolds for cartilage tissue engineering: assessment of extracellular matrix formation. Acta Biomater. 2009 Sep 26; Authors: Silva ML, Crawford A, Mundy JM, Correlo VM, Sol P, Bhattacharya M, Hatton PV, Reis RL, Neves NM Natural-based polymers have been extensively used in scaffolds production for cartilage tissue engineering. The present work aims at evaluating and characterizing extracellular matrix (ECM) formation in two types of chitosan-based scaffolds, using bovine articular chondrocytes (BAC). The influence of these scaffolds porosity, as well as pore size and geometry in cartilagineous tissue formation was studied. The effect of stirred conditions on ECM formation was also assessed. Chitosan-Poly (Butylene Succinate) (PBS) scaffolds where produced by compression moulding and salt leaching, using a blend of 50% of each material. Different porosities and pore sizes structures were obtained. BAC were seeded onto CPBS scaffolds using spinner flasks. After that period, constructs were transferred to the incubator, where half were cultured under stirred conditions, and the other half under static conditions, during 4 weeks. Constructs were characterized by scanning electron microscopy, histology procedures, immunolocalisation of collagen type I and collagen type II and dimethylmethylene blue (DMB) assay for glycosaminoglycans (GAG) quantification. Both materials showed good affinity for cell attachment. Cells colonized the entire scaffolds and were able to produce ECM. Large pores with random geometry improved proteoglycans and collagen type II production. However, that structure has the opposite effect on GAG production. Stirred culture conditions indicate to enhance GAG production, in both types of scaffolds. PMID: 19788942 [PubMed - as supplied by publisher] |
| Evaluation of Methylcellulose and Dimethylsulfoxide as the Cryoprotectants in a Serum Free Freezing Media for Cryopreservation of Adipose Derived Adult Stem Cells.
October 1, 2009 at 6:09 am
|
| | Evaluation of Methylcellulose and Dimethylsulfoxide as the Cryoprotectants in a Serum Free Freezing Media for Cryopreservation of Adipose Derived Adult Stem Cells. Stem Cells Dev. 2009 Sep 29; Authors: Thirumala S, Gimble J, Devireddy R Developing effective techniques for the cryopreservation of human Adipose Derived Adult Stem Cells (ASCs) could increase the usefulness of these cells in tissue engineering and regenerative medicine. To this end we investigated the post-freeze/thaw viability and apoptotic behavior of Passage 1 (P1) adult stem cells (ASCs) in eleven different media: (i) the traditional media containing Dulbecco's Modified Eagle Medium (DMEM) with 80% Fetal Calf Serum (FCS) and 10% dimethyl sulfoxide (DMSO), (ii) DMEM with 80% Human Serum (HS) and 10% DMSO, (iii) DMEM with 1% methyl cellulose (MC) and 10% of either HS or FCS or DMSO and (iv) DMEM with 0, 2, 4, 6, 8 or 10% DMSO. Approximately 1 ml (106 cells/ml) of P1 ASCs were frozen over night in a -80 C freezer and stored in liquid nitrogen for two weeks before being rapidly thawed in a 37 C water bath (1 to 2 minutes of agitation), re-suspended in culture media and seeded in separate wells of a 6-well plate for a 24 h incubation period at 37 C. After 24 h, the thawed samples were analyzed by brightfield microscopy and flow cytometry. The results suggest that the absence of DMSO (and the presence of MC) significantly increases the fraction of apoptotic and/or necrotic ASCs. However, the % of viable cells obtained with 2% DMSO and DMEM was comparable with that obtained in freezing media with 10% DMSO and 80% serum (HS or FCS), i.e. ~84+/-5% and ~83+/-8%, respectively. Adipogenic and osteogenic differentiation behavior of the frozen thawed cells was also assessed using histochemical staining. Our results suggest that post-thaw ASC viability, adipogenic and osteogenic differentiability can be maintained even when they are frozen in the absence of serum but with a minimal concentration of 2% DMSO in DMEM. PMID: 19788372 [PubMed - as supplied by publisher] |
|
No comments:
Post a Comment