| |  | | | | | WE'RE MAKING IMPROVEMENTS! Feed My Inbox will be undergoing maintenance on Saturday January 8th. No emails will be sent from 8am-11am CST. We appreciate your patience and are so sorry for any inconvenience this may cause. View related blog post for further details. | | | | | | | | | | | | |  | |  | | | | | TE-RegenMed-StemCell feed | | | | | | | | | | | | | | | | | | | Transplantation of Adipose Tissue-Derived Stem Cells for Treatment of Focal Cerebral Ischemia. Curr Neurovasc Res. 2011 Jan 5; Authors: Yang YC, Liu BS, Shen CC, Lin CH, Chiao MT, Cheng HC The neurological functional disabilities caused by cerebral infarction significantly deteriorate life quality and increase the medical and socio-economic costs. Although some molecular agents show potential in acting against the pathological mechanisms in animal studies, none has been proven effective for cerebral ischemia treatment in human patients. New treatment strategy needs to be developed. Stem cell therapy is promising for neural regeneration and thus become one of the current trends. More evidence has shown stem cells, such as embryonic stem cells (ESCs), skeletal muscle satellite cells and mesenchymal stem cells, to be useful in tissue repair and regeneration. However all these stem cells mentioned above have limitations. Adipose tissue-derived stem cells (ADSCs) are an alternative autologous stem cell source for the characters as abundant, easy to obtain, immunological and ethic problem free. So far, this treatment strategy has been rarely adopted on ischemic brain injury. In this study, we investigated the transplantation effects of rat ADSCs for the treatment of cerebral ischemia in rats. ADSCs were isolated from rat adipose tissue and then induced to initiate neural differentiation. Following neural induction, ADSCs developed neural morphology and displayed molecular expression of Nestin, MAP2 and GFAP. We evaluate the neurobehavioral function, infarct volume and cell properties as apoptosis, survival, migration, proliferation, differentiation and immunogenicity. Treatment with i-ADSCs (induction from ADSCs) results in better functional recovery and more reduction in hemispheric atrophy then without i-ADSCs in other groups. Our study demonstrates that i-ADSCs therapy is promising in stroke treatment and finally leads to an efficacious therapeutic modalities for much better outcome in clinical patients. PMID: 21208165 [PubMed - as supplied by publisher] | | | | | | | | | | | | | | | | | | | | | | | | | Late transplantation of allogeneic bone marrow stromal cells improves neurologic deficits subsequent to intracerebral hemorrhage. Cytotherapy. 2011 Jan 5; Authors: Otero L, Zurita M, Bonilla C, Aguayo C, Vela A, Rico MA, Vaquero J Abstract Background aims. Stem cell therapy seems to be a promising therapeutic tool for treating central nervous system (CNS) injuries. Bone marrow stromal cell (BMSC) transplantation influences functional outcome subsequent to intracerebral hemorrhage (ICH), and enhances endogenous neurogenesis in acute condition studies. We investigated whether late administration of BMSC improves functional deficits subsequent to ICH. Methods. Experimental ICH was induced by stereotactic injection of 0.5 IU collagenase type IV in the striatum of adult female Wistar rats, and 2 months later intralesional administration of 5 × 10(6) allogeneic BMSC from male donors rats in saline (n = 10), or saline only (n = 10), was performed. In the following 6 months, functional outcome was evaluated in each animal by rotarod, modified neurologic severity score (mNSS) and video-tracking box (VTB) tests. To study the behavior of BMSC after transplantation, in situ hybridization studies were performed, with double labeling of the chromosome Y-linked SrY-gene, and neuronal nuclei (NeuN) protein or gliofibrillary acidic protein (GFAP). Results. The assessment test revealed significant improvements in functional outcome for the BMSC-treated animals after 2 months of follow-up. Histologic results showed that functional outcome was associated with strong reactivation of endogenous neurogenesis. Furthermore, intralesional BMSC not only integrated in the injured tissue but also showed phenotypic expression of GFAP and NeuN. Conclusions. Late intracerebral transplantation of allogeneic BMSC induces functional recovery after ICH. The possibility of using this type of cell therapy to reverse the consequences of hemorrhagic stroke in humans should be considered. PMID: 21208021 [PubMed - as supplied by publisher] | | | | | | | | | | | | | | | | | | | | | | | | | Transplantation of Adipose Tissue-Derived Stem Cells for Treatment of Focal Cerebral Ischemia. Curr Neurovasc Res. 2011 Jan 5; Authors: Yang YC, Liu BS, Shen CC, Lin CH, Chiao MT, Cheng HC The neurological functional disabilities caused by cerebral infarction significantly deteriorate life quality and increase the medical and socio-economic costs. Although some molecular agents show potential in acting against the pathological mechanisms in animal studies, none has been proven effective for cerebral ischemia treatment in human patients. New treatment strategy needs to be developed. Stem cell therapy is promising for neural regeneration and thus become one of the current trends. More evidence has shown stem cells, such as embryonic stem cells (ESCs), skeletal muscle satellite cells and mesenchymal stem cells, to be useful in tissue repair and regeneration. However all these stem cells mentioned above have limitations. Adipose tissue-derived stem cells (ADSCs) are an alternative autologous stem cell source for the characters as abundant, easy to obtain, immunological and ethic problem free. So far, this treatment strategy has been rarely adopted on ischemic brain injury. In this study, we investigated the transplantation effects of rat ADSCs for the treatment of cerebral ischemia in rats. ADSCs were isolated from rat adipose tissue and then induced to initiate neural differentiation. Following neural induction, ADSCs developed neural morphology and displayed molecular expression of Nestin, MAP2 and GFAP. We evaluate the neurobehavioral function, infarct volume and cell properties as apoptosis, survival, migration, proliferation, differentiation and immunogenicity. Treatment with i-ADSCs (induction from ADSCs) results in better functional recovery and more reduction in hemispheric atrophy then without i-ADSCs in other groups. Our study demonstrates that i-ADSCs therapy is promising in stroke treatment and finally leads to an efficacious therapeutic modalities for much better outcome in clinical patients. PMID: 21208165 [PubMed - as supplied by publisher] | | | | | | | | | | | | | | | | | | | | | | | | | Tissue distribution of mesenchymal stem cell marker Stro-1. Stem Cells Dev. 2011 Jan 5; Authors: Lin G, Liu G, Banie L, Wang G, Ning H, Lue TF, Lin CS Stro-1 is the best-known mesenchymal stem cell (MSC) marker. However, despite its bone marrow origin, its localization in bone marrow has never been demonstrated. By immunofluorescence (IF) staining, we show here that approximately 0.74% of nucleated bone morrow cells expressed Stro-1. We also found that approximately 8.7% of CD34-expressing cells expressed Stro-1, and more than 20% of Stro-1-expressing cells did not express CD34. In adipose tissue Stro-1 expression was identified in the endothelium of arterioles and capillaries. Stro-1 was also localized in the endothelium of some but not all adipose tissue veins. Endothelial expression of Stro-1 was also identified in blood vessels in penis and in leg muscles, but not in other tested tissues. In these "other" tissues, Stro-1 was scantly expressed near but not in blood vessels. These variable and endothelial expression patterns of Stro-1 point to a need to re-examine published data that relied on Stro-1 as an MSC marker. PMID: 21208041 [PubMed - as supplied by publisher] | | | | | | | | | | | | | | | | | | | | | | | | | The effects of bioactive akermanite on physiochemical, drug-delivery, and biological properties of poly(lactide-co-glycolide) beads. J Biomed Mater Res B Appl Biomater. 2011 Feb;96(2):360-8 Authors: Liu G, Wu C, Fan W, Miao X, Sin DC, Crawford R, Xiao Y Poly(lactide-co-glycolide) (PLGA) beads have been widely studied as a potential drug/protein carrier. The main shortcomings of PLGA beads are that they lack bioactivity and controllable drug-delivery ability, and their acidic degradation by-products can lead to pH decrease in the vicinity of the implants. Akermanite (AK) (Ca(2) MgSi(2) O(7) ) is a novel bioactive ceramic which has shown excellent bioactivity and degradation in vivo. This study aimed to incorporate AK to PLGA beads to improve the physiochemical, drug-delivery, and biological properties of PLGA beads. The microstructure of beads was characterized by SEM. The effect of AK incorporating into PLGA beads on the mechanical strength, apatite-formation ability, the loading and release of BSA, and the proliferation, and differentiation of bone marrow stromal cells (BMSCs) was investigated. The results showed that the incorporation of AK into PLGA beads altered the anisotropic microporous structure into homogenous one and improved their compressive strength and apatite-formation ability in simulated body fluids (SBF). AK neutralized the acidic products from PLGA beads, leading to stable pH value of 7.4 in biological environment. AK led to a sustainable and controllable release of bovine serum albumin (BSA) in PLGA beads. The incorporation of AK into PLGA beads enhanced the proliferation and alkaline phosphatase activity of BMSCs. This study implies that the incorporation of AK into PLGA beads is a promising method to enhance their physiochemical and biological property. AK/PLGA composite beads are a potential bioactive drug-delivery system for bone tissue repair. © 2010 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 2011. PMID: 21210517 [PubMed - in process] | | | | | | | | | | | | | | | | | | | | | | | | | Micro-CT-based bone ceramic scaffolding and its performance after seeding with mesenchymal stem cells for repair of load-bearing bone defect in canine femoral head. J Biomed Mater Res B Appl Biomater. 2011 Feb;96(2):316-25 Authors: Peng J, Wen C, Wang A, Wang Y, Xu W, Zhao B, Zhang L, Lu S, Qin L, Guo Q, Dong L, Tian J Osteonecrosis of the femoral head is a debilitating and painful orthopedic condition characterized by joint collapse. Salvage of the femoral head is highly desirable to preserve the contour and mechanical properties and prevent joint collapse. This study aimed to develop a new tissue-engineering approach for treatment of large bone defect in femoral head, that is, after osteonecrosis. The biphasic calcium phosphate (BCP) ceramic scaffolds were fabricated by a 3D gel-lamination technique based on micro-computed tomography (micro-CT) images of the cancellous bone microarchitecture of femoral heads. After seeding with autologous bone marrow-derived mesenchymal stem cells (BMSCs) in vitro, the cell-scaffold composite was implanted into a bone defect surgically induced in canine femoral head via trapdoor procedure, which was a common procedure for treatment of osteonecrosis. A total of 24 adult dogs were randomly divided into three groups (n = 8 each) for implantation of the BCP scaffold with or without with BMSCs, and also the autologous bone chips for comparisons. All animals were sacrificed at 30 weeks postoperatively and processed for radiological and histological evaluations. The contour of the femoral head was well preserved with implantation of BCP scaffolds with or without BMSCs, whereas joint collapse was found after treatment with autologous bone chips. The osteointegration and new bone formation was significantly greater with BCP scaffold implantation with than without BMSC seeding and showed greater strength and compressive modulus in the repair site. Micro-CT-based bone ceramic scaffolds seeding with BMSC might be a promising way to repair bone defects in the femoral head. © 2010 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 2011. PMID: 21210512 [PubMed - in process] | | | | | | | | | | | | | | | | | | | | | | | | | Presence of pores and hydrogel composition influence tensile properties of scaffolds fabricated from well-defined sphere templates. J Biomed Mater Res B Appl Biomater. 2011 Feb;96(2):294-302 Authors: Lanasa SM, Hoffecker IT, Bryant SJ Sphere templating is an attractive method to produce porous polymeric scaffolds with well-defined and uniform pore structures for applications in tissue engineering. While high porosity is desired to facilitate cell seeding and enhance nutrient transport, the incorporation of pores will impact gross mechanical properties of tissue scaffolds and will likely be dependent on pore size. The goals of this study were to evaluate the effect of pores, pore diameter, and polymer composition on gross mechanical properties of hydrogels prepared from crosslinked poly(ethylene glycol) (PEG) and poly(2-hydroxyethyl methacrylate) (pHEMA). Sphere templates were fabricated from uncrosslinked poly(methyl methacrylate) spheres sieved between 53-63 and 150-180 μm. Incorporating pores into hydrogels significantly decreased the quasi-static modulus and ultimate tensile stress, but increased the ultimate tensile strain. For pHEMA, decreases in gel crosslinking density and increases in pore diameters followed similar trends. Interestingly, the mechanical properties of porous PEG hydrogels were less sensitive to changes in pore diameter for a given polymer composition. Additionally, pore diameter was shown to affect skeletal myoblast adhesion whereby many cells cultured in porous hydrogels with smaller pores were seen spanning across multiple pores, but lined the inside of larger pores. In summary, incorporation of pores and changes in pore diameter significantly affect the gross mechanical properties, but in a manner that is dependent on gel chemistry, structure, and composition. Together, these findings will help to design better hydrogel scaffolds for applications where gross mechanical properties and porosity are critical. © 2010 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 2011. PMID: 21210509 [PubMed - in process] | | | | | | | | | | | | | | | | | | | | | | | | | Decontamination of collagen biomatrices with combined pulsed electric field and nisin treatment. J Biomed Mater Res B Appl Biomater. 2011 Feb;96(2):287-93 Authors: Griffiths S, Maclean M, Macgregor SJ, Anderson JG, Helen Grant M Pulsed electric field (PEF) treatment has been proposed as a decontamination method for labile matrices used in tissue engineering applications. Through the application of PEF, a non-thermal treatment that causes bacterial inactivation through the irreversible rupture of microbial cell membranes, inactivation is achieved without loss of scaffold structure and function. However, some microorganisms are less susceptible to PEF treatment. This study shows that treatment with PEF and nisin, a food preservative bacteriocin, has a synergistic effect on the inactivation of Staphylococcus epidermidis in collagen gels. Almost complete inactivation of a 10(3) -10(4) CFU/mL S. epidermidis population was achieved when treated with a combination of PEF and 500 IU/mL nisin, with results demonstrating a 3.4 log(10) reduction, compared with 0.66 log(10) reduction with PEF alone. Nisin, at concentrations up to 3000 IU/mL, had no discernable toxicity to mammalian 3T3 cells when added to the culture medium or incorporated into the collagen gels. This combined decontamination method, involving PEF plus nisin, may provide a non-destructive process for inactivation of PEF-resistant bacteria in labile tissue engineering scaffolds. © 2010 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 2011. PMID: 21210508 [PubMed - in process] | | | | | | | | | | | | | | | | | | | | | | | | | Biohybrid nanofiber constructs with anisotropic biomechanical properties. J Biomed Mater Res B Appl Biomater. 2011 Feb;96(2):276-86 Authors: Bonani W, Maniglio D, Motta A, Tan W, Migliaresi C Synthetic implant materials often lack of the anisotropic mechanical properties and cell-interactive surface which are shown by natural tissues. For example, engineered vascular grafts need to be developed to address the mechanical and biological problems associated with the graft materials. This study has demonstrated a double-electrospinning fabrication process to produce a poly(ε-caprolactone)-fibroin multilayer composite which shows well-integrated nanofibrous structure, endothelial-conducive surface and anisotropic mechanical property, suitable as engineered vascular constructs. Electrospinning parameters such as voltage, solution concentration, feed rate, and relative humidity were optimized to obtain defect-free, uniform nanofibers. To mimic the different mechanical properties of natural vessels in the circumferential and longitudinal directions, a rotating cylinder was used as collector, resulting in the production of constructs with anisotropic properties. The combination of the collector shape and the collector rotation allows us to produce a tubular structure with tunable anisotropic mechanical properties. Fourier transform infrared spectroscopy, differential scanning calorimetry, and uniaxial tensile tests were used to characterize the electrospun constructs. Cell cultures with primary endothelial cells demonstrated that cells showed spread morphology and strong adhesion on fibroin richer surfaces. The platform for producing robust multilayer scaffolds with intermixing nanofiber structure, tunable anisotropy ratio, and surface with specific compositions may hold great potential in tissue engineering applications. © 2010 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 2011. PMID: 21210507 [PubMed - in process] | | | | | | | | | | | | | | | | | | | | | | | | | Micro-CT-based bone ceramic scaffolding and its performance after seeding with mesenchymal stem cells for repair of load-bearing bone defect in canine femoral head. J Biomed Mater Res B Appl Biomater. 2011 Jan 5; Authors: Peng J, Wen C, Wang A, Wang Y, Xu W, Zhao B, Zhang L, Lu S, Qin L, Guo Q, Dong L, Tian J Osteonecrosis of the femoral head is a debilitating and painful orthopedic condition characterized by joint collapse. Salvage of the femoral head is highly desirable to preserve the contour and mechanical properties and prevent joint collapse. This study aimed to develop a new tissue-engineering approach for treatment of large bone defect in femoral head, that is, after osteonecrosis. The biphasic calcium phosphate (BCP) ceramic scaffolds were fabricated by a 3D gel-lamination technique based on micro-computed tomography (micro-CT) images of the cancellous bone microarchitecture of femoral heads. After seeding with autologous bone marrow-derived mesenchymal stem cells (BMSCs) in vitro, the cell-scaffold composite was implanted into a bone defect surgically induced in canine femoral head via trapdoor procedure, which was a common procedure for treatment of osteonecrosis. A total of 24 adult dogs were randomly divided into three groups (n = 8 each) for implantation of the BCP scaffold with or without with BMSCs, and also the autologous bone chips for comparisons. All animals were sacrificed at 30 weeks postoperatively and processed for radiological and histological evaluations. The contour of the femoral head was well preserved with implantation of BCP scaffolds with or without BMSCs, whereas joint collapse was found after treatment with autologous bone chips. The osteointegration and new bone formation was significantly greater with BCP scaffold implantation with than without BMSC seeding and showed greater strength and compressive modulus in the repair site. Micro-CT-based bone ceramic scaffolds seeding with BMSC might be a promising way to repair bone defects in the femoral head. © 2010 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 2010. PMID: 21210421 [PubMed - as supplied by publisher] | | | | | | | | | | | | | | | | | | | | | | | | | The effects of bioactive akermanite on physiochemical, drug-delivery, and biological properties of poly(lactide-co-glycolide) beads. J Biomed Mater Res B Appl Biomater. 2011 Jan 5; Authors: Liu G, Wu C, Fan W, Miao X, Sin DC, Crawford R, Xiao Y Poly(lactide-co-glycolide) (PLGA) beads have been widely studied as a potential drug/protein carrier. The main shortcomings of PLGA beads are that they lack bioactivity and controllable drug-delivery ability, and their acidic degradation by-products can lead to pH decrease in the vicinity of the implants. Akermanite (AK) (Ca(2)MgSi(2)O(7)) is a novel bioactive ceramic which has shown excellent bioactivity and degradation in vivo. This study aimed to incorporate AK to PLGA beads to improve the physiochemical, drug-delivery, and biological properties of PLGA beads. The microstructure of beads was characterized by SEM. The effect of AK incorporating into PLGA beads on the mechanical strength, apatite-formation ability, the loading and release of BSA, and the proliferation, and differentiation of bone marrow stromal cells (BMSCs) was investigated. The results showed that the incorporation of AK into PLGA beads altered the anisotropic microporous structure into homogenous one and improved their compressive strength and apatite-formation ability in simulated body fluids (SBF). AK neutralized the acidic products from PLGA beads, leading to stable pH value of 7.4 in biological environment. AK led to a sustainable and controllable release of bovine serum albumin (BSA) in PLGA beads. The incorporation of AK into PLGA beads enhanced the proliferation and alkaline phosphatase activity of BMSCs. This study implies that the incorporation of AK into PLGA beads is a promising method to enhance their physiochemical and biological property. AK/PLGA composite beads are a potential bioactive drug-delivery system for bone tissue repair. © 2010 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 2010. PMID: 21210418 [PubMed - as supplied by publisher] | | | | | | | | | | | | | | | | | | | | | | | | | Synthesis and functionalization of superparamagnetic poly-{varepsilon}-caprolactone microparticles for the selective isolation of subpopulations of human adipose-derived stem cells. J R Soc Interface. 2011 Jan 5; Authors: Balmayor ER, Pashkuleva I, Frias AM, Azevedo HS, Reis RL There has been a growing interest in using biofunctionalized magnetic particles for cell isolation. This paper describes the synthesis and characterization of magnetite-polymer (Fe(3)O(4)-poly-ε-caprolactone, magnetite-PCL) microparticles surface functionalized with amino and epoxy groups allowing easy covalent attachment of specific antibodies and subsequent ability to bind target cells. Particles with different sizes (4-135 µm), spherical shape and superparamagnetic behaviour (magnetite content of about 13 wt%) were obtained. The functionalized microparticles presented high protein-binding capacity (coupling efficiency of 47% for epoxy- and 71% for amino-functionalized particles) with a low level of non-specific binding. We have further investigated the influence of initial protein concentration, pH, ionic strength, temperature and incubation time on the capacity of amino-functionalized particles to bind protein molecules. The results showed that maximum protein coupling is rapidly achieved (≤5 h) at pH 5.5 and low ionic strength (0.05 M NaCl). Furthermore, when cultured in direct contact with osteoblast-like cells (Saos-2) or human-derived adipose stem cells (ASCs), the amino-functionalized particles did not affect the proliferation and morphology of the cells. As a proof of principle for the application of magnetic microparticles for cell isolation, CD105 (endoglin) antibody was coupled to the magnetic particle surface to bind subpopulations of human ASCs expressing the CD105 antigen. The isolation of CD105+ ASCs from a heterogeneous cell population was confirmed by flow cytometry analysis. Given the demonstrated potential of functionalized magnetite-PCL microparticles for selective cell isolation, we expect that these particles may be further applied in immuno-magnetic cell separation owing to their versatility and ease of surface modification. PMID: 21208971 [PubMed - as supplied by publisher] | | | | | | | | | | | | | | | | | | | | | | | | | Incorporation of carboxylation multiwalled carbon nanotubes into biodegradable poly(lactic-co-glycolic acid) for bone tissue engineering. Colloids Surf B Biointerfaces. 2010 Dec 15; Authors: Lin C, Wang Y, Lai Y, Yang W, Jiao F, Zhang H, Ye S, Zhang Q Biodegradable poly(lactic-co-glycolic acid) (PLGA)/carboxyl-functionalized multi-walled carbon nanotube (c-MWCNT) nanocomposites were successfully prepared via solvent casting technique. Rat bone marrow-derived mesenchymal stem cells (MSCs) were employed to assess the biocompatibility of the nanocomposites in vitro. Scanning electron microscopy (SEM) observations revealed that c-MWCNTs gave a better dispersion than unmodified MWCNTs in the PLGA matrix. Surface properties were determined by means of static contact angle, X-ray photoelectron spectroscopy (XPS) and atomic force microscopy (AFM) analysis. The presence of c-MWCNTs increased the mechanical properties of the nanocomposites. Seven-week period in vitro degradation test showed the addition of c-MWCNTs accelerated the hydrolytic degradation of PLGA. In addition, SEM proved that the cells could adhere to and spread on films via cytoplasmic processes. Compared with control groups, MSCs cultured onto PLGA/c-MWCNT nanocomposites exhibited better adhesion and viability and also displayed significantly higher production levels of alkaline phosphatase (ALP) over 21 days culture. These results demonstrated that c-MWCNTs modified PLGA films were beneficial for promoting cell growth and inducing MSCs to differentiate into osteoblasts. This work presented here had potential applications in the development of 3-D scaffolds for bone tissue engineering. PMID: 21208787 [PubMed - as supplied by publisher] | | | | | | | | | | | | | | | | | | | | | | | | | Gene Expression Analysis of Mouse Embryonic Stem Cells Following Levitation in an Ultrasound Standing Wave Trap. Ultrasound Med Biol. 2011 Jan 4; Authors: Bazou D, Kearney R, Mansergh F, Bourdon C, Farrar J, Wride M In the present paper, gene expression analysis of mouse embryonic stem (ES) cells levitated in a novel ultrasound standing wave trap (USWT) (Bazou et al. 2005a) at variable acoustic pressures (0.08-0.85 MPa) and times (5-60 min) was performed. Our results showed that levitation of ES cells at the highest employed acoustic pressure for 60 min does not modify gene expression and cells maintain their pluripotency. Embryoid bodies (EBs) also expressed the early and late neural differentiation markers, which were also unaffected by the acoustic field. Our results suggest that the ultrasound trap microenvironment is minimally invasive as the biologic consequences of ES cell replication and EB differentiation proceed without significantly affecting gene expression. The technique holds great promise in safe cell manipulation techniques for a variety of applications including tissue engineering and regenerative medicine. (E-mail: Bazoud@tcd.ie). PMID: 21208732 [PubMed - as supplied by publisher] | | | | | | | | | | | | | | | | | | | | | | | | | Regeneration potential and survival of transplanted undifferentiated adipose tissue-derived stem cells in peripheral nerve conduits. J Plast Reconstr Aesthet Surg. 2010 Dec;63(12):e811-7 Authors: Erba P, Mantovani C, Kalbermatten DF, Pierer G, Terenghi G, Kingham PJ Adipose tissue-derived stem cells (ADSCs) have shown potential for the treatment of nerve injuries. Most previous efforts have aimed at stimulating regeneration by using neural-differentiation protocols, but the potential of undifferentiated ADSCs to enhance axonal growth as well as their ability to transdifferentiate in situ have been poorly investigated. In this study, using a rat sciatic nerve model we show that ADSCs, transplanted in an artificial nerve conduit, stimulate axonal outgrowth from the proximal nerve stump and evoke greater Schwann cell (SC) proliferation/intrusion in the distal stump. To track the fate of the transplanted cells, we used green fluorescent protein (GFP)-labelling and polymerase chain reaction (PCR) for the detection of the sex determining region Y (SRY) gene in the donor male cells. Both methods indicated a lack of significant quantities of viable cells 14 days after transplantation. These results suggest that any regenerative effect of transplanted ADSCs is more likely to be mediated by an initial boost of released growth factors and/or by an indirect effect on endogenous SCs activity. Future studies need to address long-term cell survival in tissue-engineered nerve conduits to improve the neuroregenerative potential of ADSCs. PMID: 20851070 [PubMed - indexed for MEDLINE] | | | | | | | | | | | | | | | | | | | | | | | | | Histological appearance of Strattice tissue matrix used in breast reconstruction. J Plast Reconstr Aesthet Surg. 2010 Dec;63(12):e840-1 Authors: Katerinaki E, Zanetto U, Sterne GD PMID: 20650694 [PubMed - indexed for MEDLINE] | | | | | | | | | | | | | | | | | | | | | | | | | Scaling the heights--challenges in medical materials. Introduction. J R Soc Interface. 2010 Aug 6;7 Suppl 4:S377-8 Authors: Edirisinghe M, Stride E PMID: 20519211 [PubMed - indexed for MEDLINE] | | | | | | | | | | | | | | | | | | | | | | | | | Activation of pluripotency genes in human fibroblast cells by a novel mRNA based approach. PLoS One. 2010;5(12):e14397 Authors: Plews JR, Li J, Jones M, Moore HD, Mason C, Andrews PW, Na J Several methods have been used to induce somatic cells to re-enter the pluripotent state. Viral transduction of reprogramming genes yields higher efficiency but involves random insertions of viral sequences into the human genome. Although induced pluripotent stem (iPS) cells can be obtained with the removable PiggyBac transposon system or an episomal system, both approaches still use DNA constructs so that resulting cell lines need to be thoroughly analyzed to confirm they are free of harmful genetic modification. Thus a method to change cell fate without using DNA will be very useful in regenerative medicine. PMID: 21209933 [PubMed - in process] | | | | | | | | | | | | | | | | | | | | | | | | | Grafted human embryonic progenitors expressing neurogenin-2 stimulate axonal sprouting and improve motor recovery after severe spinal cord injury. PLoS One. 2010;5(12):e15914 Authors: Perrin FE, Boniface G, Serguera C, Lonjon N, Serre A, Prieto M, Mallet J, Privat A Spinal cord injury (SCI) is a widely spread pathology with currently no effective treatment for any symptom. Regenerative medicine through cell transplantation is a very attractive strategy and may be used in different non-exclusive ways to promote functional recovery. We investigated functional and structural outcomes after grafting human embryonic neural progenitors (hENPs) in spinal cord-lesioned rats. PMID: 21209909 [PubMed - in process] | | | | | | | | | | | | | | | | | | | | | | | | | Human Fetal Liver Stromal Cells That Overexpress bFGF Support Growth and Maintenance of Human Embryonic Stem Cells. PLoS One. 2010;5(12):e14457 Authors: Xi J, Wang Y, Zhang P, He L, Nan X, Yue W, Pei X In guiding hES cell technology toward the clinic, one key issue to be addressed is to culture and maintain hES cells much more safely and economically in large scale. In order to avoid using mouse embryonic fibroblasts (MEFs) we isolated human fetal liver stromal cells (hFLSCs) from 14 weeks human fetal liver as new human feeder cells. hFLSCs feeders could maintain hES cells for 15 passages (about 100 days). Basic fibroblast growth factor (bFGF) is known to play an important role in promoting self-renewal of human embryonic stem (hES) cells. So, we established transgenic hFLSCs that stably express bFGF by lentiviral vectors. These transgenic human feeder cells - bFGF-hFLSCs maintained the properties of H9 hES cells without supplementing with any exogenous growth factors. H9 hES cells culturing under these conditions maintained all hES cell features after prolonged culture, including the developmental potential to differentiate into representative tissues of all three embryonic germ layers, unlimited and undifferentiated proliferative ability, and maintenance of normal karyotype. Our results demonstrated that bFGF-hFLSCs feeder cells were central to establishing the signaling network among bFGF, insulin-like growth factor 2 (IGF-2), and transforming growth factor β (TGF-β), thereby providing the framework in which hES cells were instructed to self-renew or to differentiate. We also found that the conditioned medium of bFGF-hFLSCs could maintain the H9 hES cells under feeder-free conditions without supplementing with bFGF. Taken together, bFGF-hFLSCs had great potential as feeders for maintaining pluripotent hES cell lines more safely and economically. PMID: 21209880 [PubMed - in process] | | | | | | | | | | | | | | | | | | | | | | | | | Synthesis and functionalization of superparamagnetic poly-{varepsilon}-caprolactone microparticles for the selective isolation of subpopulations of human adipose-derived stem cells. J R Soc Interface. 2011 Jan 5; Authors: Balmayor ER, Pashkuleva I, Frias AM, Azevedo HS, Reis RL There has been a growing interest in using biofunctionalized magnetic particles for cell isolation. This paper describes the synthesis and characterization of magnetite-polymer (Fe(3)O(4)-poly-ε-caprolactone, magnetite-PCL) microparticles surface functionalized with amino and epoxy groups allowing easy covalent attachment of specific antibodies and subsequent ability to bind target cells. Particles with different sizes (4-135 µm), spherical shape and superparamagnetic behaviour (magnetite content of about 13 wt%) were obtained. The functionalized microparticles presented high protein-binding capacity (coupling efficiency of 47% for epoxy- and 71% for amino-functionalized particles) with a low level of non-specific binding. We have further investigated the influence of initial protein concentration, pH, ionic strength, temperature and incubation time on the capacity of amino-functionalized particles to bind protein molecules. The results showed that maximum protein coupling is rapidly achieved (≤5 h) at pH 5.5 and low ionic strength (0.05 M NaCl). Furthermore, when cultured in direct contact with osteoblast-like cells (Saos-2) or human-derived adipose stem cells (ASCs), the amino-functionalized particles did not affect the proliferation and morphology of the cells. As a proof of principle for the application of magnetic microparticles for cell isolation, CD105 (endoglin) antibody was coupled to the magnetic particle surface to bind subpopulations of human ASCs expressing the CD105 antigen. The isolation of CD105+ ASCs from a heterogeneous cell population was confirmed by flow cytometry analysis. Given the demonstrated potential of functionalized magnetite-PCL microparticles for selective cell isolation, we expect that these particles may be further applied in immuno-magnetic cell separation owing to their versatility and ease of surface modification. PMID: 21208971 [PubMed - as supplied by publisher] | | | | | | | | | | | | | | | | | | | | | | | | | Molecular Targeting of Neural Cancer Stem Cells: TTAGGG, You're It! Clin Cancer Res. 2011 Jan 1;17(1):3-5 Authors: Hjelmeland AB, Rich JN Telomerase is an important mechanism by which cancers escape replicative senescence. In neural tumors, cancer stem cells express telomerase, suggesting that this may explain their preferential tumorigenesis. Oligonucleotide telomerase targeting selectively disrupts cancer stem cell growth through the induction of differentiation, adding to the armamentarium of anticancer stem cell therapies. Clin Cancer Res; 17(1); 3-5. ©2011 AACR. PMID: 21208901 [PubMed - in process] | | | | | | | | | | | | | | | | | | | | | | | | | Gene Expression Analysis of Mouse Embryonic Stem Cells Following Levitation in an Ultrasound Standing Wave Trap. Ultrasound Med Biol. 2011 Jan 4; Authors: Bazou D, Kearney R, Mansergh F, Bourdon C, Farrar J, Wride M In the present paper, gene expression analysis of mouse embryonic stem (ES) cells levitated in a novel ultrasound standing wave trap (USWT) (Bazou et al. 2005a) at variable acoustic pressures (0.08-0.85 MPa) and times (5-60 min) was performed. Our results showed that levitation of ES cells at the highest employed acoustic pressure for 60 min does not modify gene expression and cells maintain their pluripotency. Embryoid bodies (EBs) also expressed the early and late neural differentiation markers, which were also unaffected by the acoustic field. Our results suggest that the ultrasound trap microenvironment is minimally invasive as the biologic consequences of ES cell replication and EB differentiation proceed without significantly affecting gene expression. The technique holds great promise in safe cell manipulation techniques for a variety of applications including tissue engineering and regenerative medicine. (E-mail: Bazoud@tcd.ie). PMID: 21208732 [PubMed - as supplied by publisher] | | | | | | | | | | | | | | | | | | | | | | | | | Genetic influences on exercise-induced adult hippocampal neurogenesis across 12 divergent mouse strains. Genes Brain Behav. 2011 Jan 5; Authors: Clark PJ, Kohman RA, Miller DS, Bhattacharya TK, Brzezinska WJ, Rhodes JS New neurons are continuously born in the hippocampus of several mammalian species throughout adulthood. Adult neurogenesis represents a natural model for understanding how to grow and incorporate new nerve cells into pre-existing circuits in the brain. Finding molecules or biological pathways that increase neurogenesis has broad potential for regenerative medicine. One strategy is to identify mouse strains that display large versus small increases in neurogenesis in response to wheel running so the strains can be contrasted to find common genes or biological pathways associated with enhanced neuron formation. Therefore, mice from 12 different isogenic strains were housed with or without running wheels for 43 days to measure the genetic regulation of exercise-induced neurogenesis. The first 10 days mice received daily injections of BrdU to label dividing cells. Neurogenesis was measured as the total number of BrdU cells co-expressing NeuN mature neuronal marker in the hippocampal granule cell layer by immunohistochemistry. Exercise increased neurogenesis in all strains, but the magnitude significantly depended on genotype. Strain means for distance run on wheels, but not distance traveled in cages without wheels, were significantly correlated with strain mean level of neurogenesis. Further, certain strains displayed greater neurogenesis than others for a fixed level of running. Strain means for neurogenesis under sedentary conditions were not correlated with neurogenesis under runner conditions suggesting that different genes influence baseline versus exercise-induced neurogenesis. Genetic contributions to exercise-induced hippocampal neurogenesis suggest that it may be possible to identify genes and pathways associated with enhanced neuroplastic responses to exercise. PMID: 21208376 [PubMed - as supplied by publisher] | | | | | | | | | |  | |  | |  |
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