| CIRM Tackles $500 Million Biotech Loan Issues
October 15, 2009 at 6:41 pm
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| | A key panel of directors of the California stem cell agency next week will wrestle with a few fundamental issues concerning its ambitious, $500 million biotech loan program.Matters such as the process for financial review of loan applications, unspecified changes in the loan administration policy and criteria for eligibility for recourse loans are on the table for a teleconference meeting of the |
| New BioTime Subsidiary, OncoCyte Corporation, Receives $2 Million Equity Financing to Develop Cancer Treatments Using Stem Cell Technology
October 15, 2009 at 5:45 pm
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| ID3 provides career counseling for blood progenitors, driving the creation of gamma-delta T cells
October 15, 2009 at 1:44 pm
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| BIDMC scientist John Rinn named one of the 'Brilliant 10' BY Popular Science magazine
October 15, 2009 at 9:41 am
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| The phenotypic responses of human anterior cruciate ligament cells cultured on poly(epsilon-caprolactone) and chitosan.
October 15, 2009 at 6:40 am
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| | The phenotypic responses of human anterior cruciate ligament cells cultured on poly(epsilon-caprolactone) and chitosan. J Biomed Mater Res A. 2009 Oct 13; Authors: Shao HJ, Chen CS, Lee YT, Wang JH, Young TH The purpose of this study is to evaluate the phenotypic responses of human anterior cruciate ligament (ACL) cells on two biodegradable materials: poly(epsilon-caprolactone) (PCL) and chitosan. ACL cells cultured on PCL displayed phenotypes that were well spread with a developed cytoskeleton. In comparison, chitosan was not an appropriate substrate to support the attachment and spreading of ACL cells, which was attributed to the low fibronectin (FN) adsorption of chitosan. However, ACL cells cultured on chitosan exhibited a dramatic effect on increasing transcripts of transforming growth factor beta1 (TGF beta1) and collagen III. After coating FN on chitosan surface, cell morphology and the mRNA levels of all tested genes had the similar levels on PCL and FN-coated chitosan. This indicates the expression of TGF beta1 and collagen III mRNA of human ACL cells was seem to correlate closely with the adhesion behavior of human ACL cells and was influenced by the underlying substrate properties. Since an ideal scaffold used in ACL tissue engineering is not only for cell attachment but also for extracellular matrix deposition during ligament regeneration, chitosan may be considered as a scaffold for ACL tissue engineering, which can upregulate the expression of specific genes of matrix production and wound healing in human ACL cells to synthesize more quantity of FN and TGF beta1 proteins. (c) 2009 Wiley Periodicals, Inc. J Biomed Mater Res 2009. PMID: 19827113 [PubMed - as supplied by publisher] |
| In vitro electromagnetically stimulated SAOS-2 osteoblasts inside porous hydroxyapatite.
October 15, 2009 at 6:40 am
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| | In vitro electromagnetically stimulated SAOS-2 osteoblasts inside porous hydroxyapatite. J Biomed Mater Res A. 2009 Oct 13; Authors: Fassina L, Saino E, Sbarra MS, Visai L, De Angelis MG, Magenes G, Benazzo F One of the key challenges in reconstructive bone surgery is to provide living constructs that possess the ability to integrate in the surrounding tissue. Bone graft substitutes, such as autografts, allografts, xenografts, and biomaterials have been widely used to heal critical-size long bone defects due to trauma, tumor resection, congenital deformity, and tissue degeneration. In particular, porous hydroxyapatite is widely used in reconstructive bone surgery owing to its biocompatibility. In addition, the in vitro modification of hydroxyapatite with osteogenic signals enhances the tissue regeneration in vivo, suggesting that the biomaterial modification could play an important role in tissue engineering. In this study we have followed a biomimetic strategy where electromagnetically stimulated SAOS-2 human osteoblasts proliferated and built their extracellular matrix inside a porous hydroxyapatite scaffold. The electromagnetic stimulus had the following parameters: intensity of the magnetic field equal to 2 mT, amplitude of the induced electric tension equal to 5 mV, frequency of 75 Hz, and pulse duration of 1.3 ms. In comparison with control conditions, the electromagnetic stimulus increased the cell proliferation and the surface coating with bone proteins (decorin, osteocalcin, osteopontin, type-I collagen, and type-III collagen). The physical stimulus aimed at obtaining a better modification of the biomaterial internal surface in terms of cell colonization and coating with bone matrix. (c) 2009 Wiley Periodicals, Inc. J Biomed Mater Res 2009. PMID: 19827111 [PubMed - as supplied by publisher] |
| Fabrication and characterization of novel hybrid organic/inorganic microparticles to apply in bone regeneration.
October 15, 2009 at 6:40 am
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| | Fabrication and characterization of novel hybrid organic/inorganic microparticles to apply in bone regeneration. J Biomed Mater Res A. 2009 Oct 13; Authors: Jayasuriya AC, Bhat A The aim of this study was to fabricate and characterize the novel hybrid organic/inorganic microparticles (MPs) to apply in bone regeneration. These hybrid MPs were fabricated using a scale-up method we have developed to increase the yield of chitosan (CS) MPs. The MPs were based on the CS and consist of inorganic components such as dibasic calcium phosphate (CaHPO(4)) or calcium carbonate (CaCO(3)). Tripolyphosphate (TPP) has been used as a cross-linking agent to form cross-links between the amine groups in CS and phosphate groups in TPP. Four types of hybrid MPs were fabricated: CS; CS-10%CaHPO(4); CS-20%CaHPO(4); CS-10% CaCO(3). SEM images revealed that all types of MPs were approximately spherical in shape and most of them were with a diameter range of 30-60 mum. XRD reveals the evidence of having CaHPO(4) or CaCO(3) in the CS-10%CaHPO(4), CS-20%CaHPO(4), or CS-10%CaCO(3) MPs, respectively. All types of MPs have shown the existence of cross-links according to FTIR. We have studied the mesenchymal stem cell (MSC) attachment on the surfaces of all types of MPs compared to control wells at 4, 8, 25, and 48 h. The attached MSCs on all types of MPs were increased more than two-fold at 48 h compared with that of 4 h. These hybrid MPs have a great potential to apply as a bone-void filler or bone tissue engineering scaffold to treat the bone defects. (c) 2009 Wiley Periodicals, Inc. J Biomed Mater Res 2009. PMID: 19827109 [PubMed - as supplied by publisher] |
| Lentivirus delivery by adsorption to tissue engineering scaffolds.
October 15, 2009 at 6:40 am
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| | Lentivirus delivery by adsorption to tissue engineering scaffolds. J Biomed Mater Res A. 2009 Oct 13; Authors: Shin S, Salvay DM, Shea LD Biomaterial scaffolds capable of localized gene delivery are being investigated for numerous regenerative medicine applications and as model systems for fundamental studies of tissue formation. In this manuscript, we investigate the delivery of lentivirus from a tissue engineering scaffold using a surface immobilization strategy. Poly(lactide-co-glycolide) (PLG) was employed as the biomaterial for delivery, which has been widely used for a number of tissue engineering applications. The virus was immobilized by freezing and subsequent lyophilization of the virus with the scaffold. The presence of sucrose during freezing and lyophilization maintained the activity of the lentivirus, and was similar to an adenovirus control. Collagen and fibronectin were investigated for their ability to enhance surface immobilization. Fibronectin modestly increased binding and transduction of the adenovirus, yet did not significantly impact the lentivirus delivery. Most of the immobilized lentivirus was released from the scaffold within 24 h. In vivo implantation of the scaffolds yielded transgene expression that persisted for at least 4 weeks. These findings indicate the potential for delivering lentivirus from tissue engineering scaffolds using a surface immobilization strategy. To our knowledge, this report is the first to investigate lentivirus delivery from porous tissue engineering scaffolds. Delivery of lentiviral vectors from PLG scaffolds could provide an efficient and versatile gene delivery system for use with in vitro and in vivo models of tissue formation, and ultimately for therapeutic applications. (c) 2009 Wiley Periodicals, Inc. J Biomed Mater Res 2009. PMID: 19827108 [PubMed - as supplied by publisher] |
| [Osteoblasts : Cellular and molecular regulatory mechanisms in fracture healing.]
October 15, 2009 at 6:40 am
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| | [Osteoblasts : Cellular and molecular regulatory mechanisms in fracture healing.] Orthopade. 2009 Oct 15; Authors: Hofmann A, Mattyasovszky SG, Brüning C, Ritz U, Mehling I, Meurer A, Rommens PM Bone tissue possesses a unique regeneration ability, translating mechanical and metabolic stimuli into a biological response. The perpetual regeneration processes allow continuous self-renewal and adaptation to prevailing mechanical forces. The complex regulation of osteoblastic differentiation during fracture repair has not been completely defined. Two different transcription factors - RUNX2 and SP7 - are considered to be master genes of osteoblastic differentiation. Furthermore, the canonical WNT pathway plays an essential role in the activation of osteoblastic differentiation during both bone growth and fracture healing. Studies of fracture healing have revealed that downregulation of the WNT pathway causes a significant reduction in new bone formation. Moreover, correct WNT signalling is also required for BMP2-induced bone formation. There is increasing evidence that patients who develop recalcitrant fracture nonunions exhibit not only reduced numbers and differentiation capacity of osteogenic progenitors but also a significant downregulation of numerous factors in the WNT pathway. Therefore, better understanding of the WNT regulatory mechanisms could reveal new strategies for the treatment of delayed fracture healing and for the tissue engineering of bone. PMID: 19826779 [PubMed - as supplied by publisher] |
| Immunomodulatory properties of mesenchymal stromal cells and their therapeutic consequences for immune-mediated disorders.
October 15, 2009 at 6:40 am
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| | Immunomodulatory properties of mesenchymal stromal cells and their therapeutic consequences for immune-mediated disorders. Stem Cells Dev. 2009 Oct 13; Authors: Zhao S, Wehner R, Bornhäuser M, Wassmuth R, Bachmann M, Schmitz M Bone marrow-derived mesenchymal stromal cells (MSCs) represent a population of non-hematopoietic cells, which play a crucial role in supporting hematopoiesis and can differentiate into various cell types such as osteocytes, chondrocytes, adipocytes and myocytes. Due to their differentiation capability, MSCs emerge as promising candidates for therapeutic applications in tissue engineering. In addition, they display immunomodulatory properties, that have prompted consideration of their potential use for treatment modalities aimed at the inhibition of immune responses. In this context, MSCs efficiently inhibit maturation, cytokine production and T-cell stimulatory capacity of dendritic cells. They also markedly impair proliferation, cytokine secretion and cytotoxic potential of natural killer cells and T lymphocytes. Furthermore, MSCs are able to inhibit the proliferation of B cells and their capacity to produce antibodies. Various animal models confirm the immunomodulatory properties of MSCs. Thus, administered MSCs prolong the survival of skin and cardiac allografts and ameliorate acute graft-versus-host disease (GVHD) as well as experimental autoimmune encephalomyelitis. Clinical studies enrolling patients with severe acute GVHD reveal that the administration of MSCs results in significant clinical responses. Due to their immunomodulatory capability and their low immunogenicity, MSCs represent promising candidates for the prevention and treatment of immune-mediated diseases. PMID: 19824807 [PubMed - as supplied by publisher] |
| Recent Trends and Challenges in Complex Organ Manufacturing.
October 15, 2009 at 6:40 am
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| | Recent Trends and Challenges in Complex Organ Manufacturing. Tissue Eng Part B Rev. 2009 Oct 13; Authors: Wang X, Yan Y, Zhang R Presently, there is a recognized and imperative need for bioartificial organs. The technological advances in transgenosis, tissue engineering and rapid prototyping (RP) have led to the development of spatially complex tissues. An ideal artificial organ should provide nutrient transport system, mechanical stable architecture and synergetic multi-cellular organization in one construct. The multi-nozzle RP technique simultaneously assembles vascular systems including hierarchical multi-cellular structures in an automated and reproducible manner and offers an effective way for treating organ failures. In this article, a brief overview of the recent trends and outstanding challenges in organ manufacturing is provided. From the viewpoint of disciplinary crossing, integration and development, future directions in the coming year were pointed out. PMID: 19824803 [PubMed - as supplied by publisher] |
| Lentivirus delivery by adsorption to tissue engineering scaffolds.
October 15, 2009 at 6:36 am
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| | Lentivirus delivery by adsorption to tissue engineering scaffolds. J Biomed Mater Res A. 2009 Oct 13; Authors: Shin S, Salvay DM, Shea LD Biomaterial scaffolds capable of localized gene delivery are being investigated for numerous regenerative medicine applications and as model systems for fundamental studies of tissue formation. In this manuscript, we investigate the delivery of lentivirus from a tissue engineering scaffold using a surface immobilization strategy. Poly(lactide-co-glycolide) (PLG) was employed as the biomaterial for delivery, which has been widely used for a number of tissue engineering applications. The virus was immobilized by freezing and subsequent lyophilization of the virus with the scaffold. The presence of sucrose during freezing and lyophilization maintained the activity of the lentivirus, and was similar to an adenovirus control. Collagen and fibronectin were investigated for their ability to enhance surface immobilization. Fibronectin modestly increased binding and transduction of the adenovirus, yet did not significantly impact the lentivirus delivery. Most of the immobilized lentivirus was released from the scaffold within 24 h. In vivo implantation of the scaffolds yielded transgene expression that persisted for at least 4 weeks. These findings indicate the potential for delivering lentivirus from tissue engineering scaffolds using a surface immobilization strategy. To our knowledge, this report is the first to investigate lentivirus delivery from porous tissue engineering scaffolds. Delivery of lentiviral vectors from PLG scaffolds could provide an efficient and versatile gene delivery system for use with in vitro and in vivo models of tissue formation, and ultimately for therapeutic applications. (c) 2009 Wiley Periodicals, Inc. J Biomed Mater Res 2009. PMID: 19827108 [PubMed - as supplied by publisher] |
| The Beauty of Being a Variant: H2A.Z and the SWR1 Complex in Plants.
October 15, 2009 at 6:36 am
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| | The Beauty of Being a Variant: H2A.Z and the SWR1 Complex in Plants. Mol Plant. 2009 Jul;2(4):565-577 Authors: March-Díaz R, Reyes JC Numerous studies have shown that the nucleosome is a dynamic structure that strongly influences gene expression. Dynamism concerns different nucleosomal characteristics, including position, posttranslational modifications, and histone composition. Thus, within the nucleosome, canonical histones can be exchanged by histone variant proteins with specific functions-a process known as 'histone replacement'. The histone variant H2A.Z has an important function in transcription and, during the last few years, its role in plant development and immune response has become evident. Compiling genetic and biochemical studies from several laboratories has revealed that plants contain a multiprotein complex, similar to the SWR1/SRCAP complex from yeast and animals, involved in H2A.Z deposition. Despite intense research in different organisms, the mechanism by which H2A.Z influences transcription is still unknown. However, recent results from Arabidopsis have shown a strong inverse correlation between H2A.Z and DNA methylation, suggesting that H2A.Z might protect genes from silencing. PMID: 19825639 [PubMed - as supplied by publisher] |
| Pulsed DC Electric Fields enhance osteogenesis in adipose-derived stromal cells.
October 15, 2009 at 6:36 am
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| | Pulsed DC Electric Fields enhance osteogenesis in adipose-derived stromal cells. Tissue Eng Part A. 2009 Oct 13; Authors: Hammerick KE, James AW, Huang Z, Prinz FB, Longaker M Adipose-derived stromal cells (ASCs) constitute a promising source of cells for regenerative medicine applications. Previous studies of osteogenic potential in ASCs have focused on chemicals, growth factors, and mechanical stimuli. Citing the demonstrated role electric fields play in enhancing healing in bone fractures and defects, we investigated the ability of pulsed direct current (DC) electric fields to drive osteogenic differentiation in mouse ASCs. Employing 50 Hz DC electric fields in concert with and without osteogenic factors, we demonstrated increased early osteoblast specific markers. We were also able to establish that commonly reported artifacts of electric field stimulation are not the primary mediators of the observed effects. The electric fields caused marked changes in the cytoskeleton. We used atomic force microscopy (AFM) based force spectroscopy to record an increase in cytoskeletal tension after treatment with electric fields. We abolished the increased cytoskeletal stresses with the rho-associated protein kinase inhibitor, Y27632, and did not see any decrease in osteogenic gene expression, suggesting that the pro-osteogenic effects of electric fields are not transduced via cytoskeletal tension. Electric fields may show promise as candidate enhancers of osteogenesis of ASCs and may be incorporated into cell-based strategies for skeletal regeneration. PMID: 19824802 [PubMed - as supplied by publisher] | 
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