| Bone marrow cells may significantly reduce risk of second heart attack
December 8, 2009 at 6:00 pm
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| Coverage Planned of CIRM Directors Meeting Wednesday and Thursday
December 8, 2009 at 5:38 pm
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| | The California Stem Cell Report will be monitoring from Mexico the two-day meeting of the directors of the California stem cell agency. We will file fresh items as warranted beginning late tomorrow afternoon and continuing into Thursday. |
| UT Houston researchers launch phase II trial of stem cells and acute heart attack
December 8, 2009 at 5:00 pm
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| Supportive materials will help regenerate heart tissue
December 8, 2009 at 5:00 pm
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| Gene therapy and stem cells save limb
December 8, 2009 at 5:00 pm
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| 'Art gallery' of cell recognized at ASCB annual meeting
December 8, 2009 at 5:00 pm
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| Problems With CIRM's $1 Million, Free HQ Lease
December 8, 2009 at 3:51 pm
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| | Back in 2005, the California stem cell agency snagged a free, 10-year lease for office space in San Francisco to house its $3 billion effort.But today something is amiss. All the details are not clear, although CIRM is looking at having someone set up a nonprofit to handle the lease, according to our source. We understand that the agency cannot afford to assume additional expenses because of a 3 |
| Stem Cell Based Treatment for Spinal Muscular Atrophy Receives Orphan Drug Designation
December 8, 2009 at 1:59 pm
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| Human umbilical stem cells cleared mice's cloudy eyes
December 8, 2009 at 1:59 pm
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| Inside Stem Cell Funding: The Cost of Making a Grant
December 8, 2009 at 1:02 pm
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| | How much does it cost to give away $230 million? Something more than $173,000 or about $12,000 for each of the 14 awards in the recent disease team round from the California stem cell agency.Those are conservative figures based on a document posted Sunday on the CIRM Web site. The report said it could have cost up to $280,000 to approve all the grants in the disease team round if the new "PreApp" |
| Aldagen Announces Data Presented at American Society of Hematology Annual Meeting
December 8, 2009 at 12:59 pm
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| Umbilical stem cells may help recover lost vision for those with corneal disease
December 8, 2009 at 12:59 pm
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| Autologous stem cell transplantation for soft tissue sarcoma: insufficient research into therapy
December 8, 2009 at 12:59 pm
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| Venture Capitalist, Bankers to Weigh In on $500 Million Loan Program
December 8, 2009 at 10:26 am
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| | The California stem cell agency is promising an interesting cast of characters for its meeting tomorrow concerning its fledgling $500 million biotech loan program.Representatives from Proteus Venture Partners, VitaPath Genetics, Inc., Burrill & Co. and Silicon Valley Bank have been invited to appear, according to a document posted today.Duane Roth, chairman of the CIRM Loan Task Force, says that |
| [Autologous stem cell therapy with surgical myocardial revascularization.]
December 8, 2009 at 8:38 am
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| | [Autologous stem cell therapy with surgical myocardial revascularization.] Anadolu Kardiyol Derg. 2009 Dec;9(6):465-6 Authors: Durdu S, Cubukçuoğlu Deniz G, Akar AR PMID: 19965316 [PubMed - in process] |
| [Autologous stem cell therapy with surgical myocardial revascularization - The Rostock University experience.]
December 8, 2009 at 8:38 am
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| | [Autologous stem cell therapy with surgical myocardial revascularization - The Rostock University experience.] Anadolu Kardiyol Derg. 2009 Dec;9(6):457-64 Authors: Yerebakan C, Uğurlucan M, Kaminski A, Westphal B, Liebold A, Steinhoff G OBJECTIVE: Stem cell therapy has gained great attraction in the treatment of acute and chronic myocardial diseases in recent years. The aim was to evaluate our experience in light of the middle term results of intramyocardial stem cell treatment with concomitant coronary artery bypass surgery (CABG) since 2001. Methods: After encouraging initial results of the Phase I (safety) trial with the first 15 patients, a prospective, controlled Phase II (efficacy) study was begun with 40 patients aiming to determine functional benefit of stem cell treatment using bone marrow derived CD 133+stem cell therapy with concomitant CABG in comparison to CABG only since 2003. Medium-term results of intervention were evaluated using patient's clinical findings, Holter monitoring, echocardiography, magnetic resonance imaging, computed tomography and myocardial scintigraphy. Statistical analyses were performed using unpaired t, Mann-Whitney U, ANOVA for repeated measurements and Chi-square tests. RESULTS: Left ventricular ejection fraction (LVEF) has increased significantly at 6th and 18th months follow-up in the first 15 patients who received therapy since 2001 (preoperative: 39.0+/- 8.7%; 6th month: 50.2+/- 8.5% and 18th month: 47.9+/- 6.0%; p=0.012). In the late group of patients, LVEF increased from 37.4+/- 8.4% to 47.1+/- 8.3% (p<0.001) whilst although an increase in LVEF has been observed in the CABG alone group (from 37.9+/- 10.3% to 41.3+/- 9.1%) the increase has not been statistically significant. Mortality occurred in 2 patients [1 patient from the early and 1 patient from the medium term follow-up] due to non-cardiac reasons. Myocardial calcification, lethal ventricular arrhythmia, and tumor formation have not been observed in any of the patients in the long-term follow up. CONCLUSION: Direct injection of bone marrow derived CD 133+ stem cells into the myocardium with concomitant CABG is safe. However, this treatment modality may only be applied as standard treatment after completion of the long- term detailed results of prospective, randomized multicenter trials. PMID: 19965315 [PubMed - in process] |
| Stem cell therapy for the treatment of acute myocardial infarction.
December 8, 2009 at 8:38 am
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| | Stem cell therapy for the treatment of acute myocardial infarction. Cardiol Clin. 2010 Feb;28(1):127-38 Authors: Dinsmore JH, Dib N The last decade has been accompanied by great optimism and interest in the concept of cell or tissue regeneration in the postinfarction myocardium. However, despite the promise, progress was slow. Data derived from multiple controlled studies in hundreds of patients postmyocardial infarction have shown hints of potential benefit but not of the magnitude anticipated. The complexity and hurdles to repair the damaged myocardium have been more daunting than originally estimated. In the end analysis, progress will be made incrementally. The promise for cell therapy continues to be significant, but so are the challenges ahead. This article takes a fresh look at the progress in myocardial regeneration. The authors look at the postmyocardial environment for cues that may guide repair and they look closely at the clinical data for evidence of cardiac regeneration. This evidence is used for suggestions on how to best proceed with future work. PMID: 19962054 [PubMed - in process] |
| Millipore Sponsors Three Academic Memberships for the MetaMiner Stem Cell Project
December 8, 2009 at 7:58 am
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| Cryopreservation of stromal vascular fraction of adipose tissue in a serum-free freezing medium.
December 8, 2009 at 7:05 am
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| | Cryopreservation of stromal vascular fraction of adipose tissue in a serum-free freezing medium. J Tissue Eng Regen Med. 2009 Dec 4; Authors: Thirumala S, Gimble JM, Devireddy RV Developing effective techniques for the cryopreservation of human adipose-derived adult stem cells could increase the usefulness of these cells in tissue engineering and regenerative medicine. Unfortunately, the use of serum and a commonly used cryoprotectant chemical, dimethyl sulphoxide (DMSO), during cryopreservation storage restricts the direct translation of adult stem cells to in vivo applications. The objective of this study was to test the hypothesis that the stromal vascular fraction (SVF) of adipose tissue can be effectively cryopreserved and stored in liquid nitrogen, using a freezing medium containing high molecular weight polymers, such as methylcellulose (MC) and/or polyvinylpyrollidone (PVP), as the cryoprotective agent (CPA) instead of DMSO. To this end, we investigated the post-freeze/thaw viability and apoptotic behaviour of SVF of adipose tissue frozen in 16 different media: (a) the traditional medium containing Dulbecco's modified Eagle's medium (DMEM) with 80% fetal calf serum (FCS) and 10% DMSO; (b) DMEM with 80% human serum (HS) and 10% DMSO; (c) DMEM with 0%, 2%, 4%, 6%, 8% or 10% DMSO; (d) DMEM with 1% MC and 10% of either HS or FCS or DMSO; (e) DMEM with 10% PVP and varying concentrations of FCS (0%, 10%, 40% or 80%); (f) DMEM with 10% PVP and 10% HS. Approximately 1 ml (10(6) cells/ml) of SVF cells were frozen overnight in a -80 degrees C freezer and stored in liquid nitrogen for 2 weeks before being rapidly thawed in a 37 degrees C water bath (1-2 min agitation), resuspended in culture medium and seeded in separate wells of a six-well plate for a 24 h incubation period at 37 degrees C. After 24 h, the thawed samples were analysed 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 SVF cells. However, the percentage of viable cells obtained with 10% PVP and DMEM was comparable with that obtained in freezing medium with DMSO and serum (HS or FCS), i.e. approximately 54 +/- 14% and approximately 63 +/- 10%, respectively. Adipogenic and osteogenic differentiation behaviour of the frozen thawed cells was also assessed, using histochemical staining. Our results suggest that post-thaw SVF cell viability and adipogenic and osteogenic differentiability can be maintained even when they are frozen in the absence of serum and DMSO but with 10% PVP in DMEM. Copyright (c) 2009 John Wiley & Sons, Ltd. PMID: 19967746 [PubMed - as supplied by publisher] |
| Skeletal tissue engineering using embryonic stem cells.
December 8, 2009 at 7:05 am
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| | Skeletal tissue engineering using embryonic stem cells. J Tissue Eng Regen Med. 2009 Dec 4; Authors: Jukes JM, van Blitterswijk CA, de Boer J Various cell types have been investigated as candidate cell sources for cartilage and bone tissue engineering. In this review, we focused on chondrogenic and osteogenic differentiation of mouse and human embryonic stem cells (ESCs) and their potential in cartilage and bone tissue engineering. A decade ago, mouse ESCs were first used as a model to study cartilage and bone development and essential genes, factors and conditions for chondrogenesis and osteogenesis were unravelled. This knowledge, combined with data from the differentiation of adult stem cells, led to successful chondrogenic and osteogenic differentiation of mouse ESCs and later also human ESCs. Next, researchers focused on the use of ESCs for skeletal tissue engineering. Cartilage and bone tissue was formed in vivo using ESCs. However, the amount, homogeneity and stability of the cartilage and bone formed were still insufficient for clinical application. The current protocols require improvement not only in differentiation efficiency but also in ESC-specific hurdles, such as tumourigenicity and immunorejection. In addition, some of the general tissue engineering challenges, such as cell seeding and nutrient limitation in larger constructs, will also apply for ESCs. In conclusion, there are still many challenges, but there is potential for ESCs in skeletal tissue engineering. Copyright (c) 2009 John Wiley & Sons, Ltd. PMID: 19967745 [PubMed - as supplied by publisher] |
| Functional life-long maintenance of engineered liver tissue in mice following transplantation under the kidney capsule.
December 8, 2009 at 7:05 am
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| | Functional life-long maintenance of engineered liver tissue in mice following transplantation under the kidney capsule. J Tissue Eng Regen Med. 2009 Dec 4; Authors: Ohashi K, Koyama F, Tatsumi K, Shima M, Park F, Nakajima Y, Okano T The ability to engineer biologically active cells and tissue matrices with long-term functional maintenance has been a principal focus for investigators in the field of hepatocyte transplantation and liver tissue engineering. The present study was designed to determine the efficacy and temporal persistence of functional engineered liver tissue following transplantation under the kidney capsule of a normal mouse. Hepatocytes were isolated from human alpha-1 antitrypsin (hA1AT) transgenic mouse livers. Hepatocytes were subsequently transplanted under the kidney capsule space in combination with extracellular matrix components (Matrigel) for engineering liver tissues. The primary outcome of interest was to assess the level of engineering liver tissue function over the experimental period, which was 450 days. Long-term survival by the engineered liver tissue was confirmed by measuring the serum level of hA1AT in the recipient mice throughout the experimental period. In addition, administration of chemical compounds at day 450 resulted in the ability of the engineered liver tissue to metabolize exogenously circulating compounds and induce drug-metabolizing enzyme production. Moreover, we were able to document that the engineered tissues could retain their native regenerative potential similar to that of naïve livers. Overall, these results demonstrated that liver tissues could be engineered at a heterologous site while stably maintaining its functionality for nearly the life span of a normal mouse. Copyright (c) 2009 John Wiley & Sons, Ltd. PMID: 19967744 [PubMed - as supplied by publisher] |
| Effects of BMP-2 and dexamethasone on osteogenic differentiation of rat dental follicle progenitor cells seeded on three-dimensional beta-TCP.
December 8, 2009 at 7:05 am
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| | Effects of BMP-2 and dexamethasone on osteogenic differentiation of rat dental follicle progenitor cells seeded on three-dimensional beta-TCP. Biomed Mater. 2009 Dec 7;4(6):65010 Authors: Xu LL, Liu HC, Wang DS, E LL, Xu L, Jin ZL, Duan YZ The aim of this study was to investigate the effects of BMP-2 and dexamethasone (Dex) on osteogenic differentiation of rat dental follicle progenitor cells (RDFCs) seeded on three-dimensional beta-TCP. The alkaline phosphatase (ALP), the calcium and phosphonium, the osteocalcin in media of the third passage RDFCs on biomaterial beta-TCP after 1-3, 3-7, 7-14 days of culture were examined respectively. The growth of cells on the scaffolds was observed by scanning electron microscope (SEM) after 3, 7 days of culture and by implanting in the backs of severe combined immunodeficient (SCID) mice for bone regeneration. The third passage RDFCs could be seen adhered, extended and proliferated on the beta-TCP by scanning electron microscopy. The ALP activity, the calcium and phosphoniums and the osteocalcin content of dexamethasone (10(-8) M) or/and BMP-2 (100 ng ml(-1)) were significantly higher than their existence in the control group. They were the significantly highest among four groups after joint application of BMP-2 and dexamethasone. After 8 weeks of implantation, the percentage of the new bones formed area in the RDFCs+beta-TCP+BMP-2+Dex group was significantly higher than that in the RDFCs+beta-TCP+BMP-2 group. In contrast, beta-TCP, RDFCs+beta-TCP+Dex and control constructs lacked new bone formation by histological staining and histomorphometric analysis. The BMP-2+Dex could significantly promote osteogenic differentiation of RDFCs on beta-TCP. beta-TCP supported fast cellular adhesion, proliferation and differentiation of RDFCs. The feasibility of its application in periodontal tissue engineering was also proved. PMID: 19966384 [PubMed - as supplied by publisher] |
| Developmental effects of low frequency magnetic fields on P19-derived neuronal cells.
December 8, 2009 at 7:05 am
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| | Developmental effects of low frequency magnetic fields on P19-derived neuronal cells. Conf Proc IEEE Eng Med Biol Soc. 2009;1:5942-5 Authors: Saito A, Takayama Y, Moriguchi H, Kotani K, Jimbo Y Modulation of pluripotent stem cell differentiation by several environmental factors, such as physical stimulation, is important theme in tissue engineering. In this study, we report the effects of extremely low frequency magnetic fields (ELF-MFs) exposure (1 mT or 10 mT, 50 Hz, sinusoidal) on the neuronal differentiation process of P19 embryonal carcinoma cells (P19 cells). Here, during induction of differentiation, the ELF-MFs exposed to embryoid bodies (EBs). After neuronal differentiation, the effects of ELF-MFs were evaluated by morphological analysis, immunochemical analysis (MAP2, GFAP), and the developmental neuronal network activities recorded by the micro-electrode arrays (MEAs). As a result, the percentage of MAP2 positive cells and the spike frequencies were increased by 10 mT ELF-MF, and then the percentage of GFAP positive cells were reduced. However, these effects were not seen in 1 mT exposed cells. Therefore, these results suggested that the intensity of a magnetic field was important for affecting a characteristic of neuronal differentiation and a functional neuronal network property. PMID: 19965063 [PubMed - in process] |
| Injectable myocardial matrix as a scaffold for myocardial tissue engineering.
December 8, 2009 at 7:05 am
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| | Injectable myocardial matrix as a scaffold for myocardial tissue engineering. Conf Proc IEEE Eng Med Biol Soc. 2009;1:2406-8 Authors: Singelyn JM, Dequach JA, Christman KL Current injectable materials utilized in myocardial tissue engineering have been borrowed from other tissue engineering applications and have not been specifically designed for the myocardium. We have recently tested the feasibility of using an injectable form of myocardial extracellular matrix that would provide cardiac specific matrix cues as well as be amenable to minimally invasive delivery. We have demonstrated that this material self-assembles in vivo to form a nanofibrous scaffold, which supports the infiltration of neovasculature. We have also demonstrated that this material may be delivered minimally invasively through a catheter. PMID: 19964956 [PubMed - in process] |
| Temporal and spatial control over soluble protein signaling for musculoskeletal tissue engineering.
December 8, 2009 at 7:05 am
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| | Temporal and spatial control over soluble protein signaling for musculoskeletal tissue engineering. Conf Proc IEEE Eng Med Biol Soc. 2009;1:2103-5 Authors: Murphy WL Orthopedic tissue engineering strategies have developed rapidly in response to large and growing clinical needs. However, current clinical methods for replacement of natural tissue function have significant limitations, and pragmatic challenges have hindered clinical use of emerging tissue engineering approaches. In addition, current methods are not yet capable of achieving complex spatial and temporal regulation of soluble signaling (e.g. growth factor signaling), which may be required for complex, functional tissue regeneration. We have begun to develop a series of new medical devices, which are designed to temporally and spatially regulate growth factor and cytokine signaling during tissue regeneration. The initial goal of these studies is to regulate the behavior of multipotent stem cells, and to promote formation of clinically relevant tissue interfaces (e.g. bone-tendon interfaces). The ultimate goal is to further understand and recapitulate the complex processes that lead to functional musculoskeletal development and regeneration. PMID: 19964780 [PubMed - in process] |
| Designer protein-based scaffolds for neural tissue engineering.
December 8, 2009 at 7:05 am
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| | Designer protein-based scaffolds for neural tissue engineering. Conf Proc IEEE Eng Med Biol Soc. 2009;1:2101-2 Authors: Straley K, Heilshorn SC A key attribute missing from many current biomaterials is the ability to independently tune multiple biomaterial properties without simultaneously affecting other material parameters. Because cells are well known to respond to changes in the initial elastic modulus, degradation rate, and cell adhesivity of a biomaterial, it is critical to develop synthetic design strategies that allow decoupled tailoring of each individual parameter in order to systematically optimize cell-scaffold interactions. We present the development of a family of biomimetic scaffolds composed of chemically crosslinked, elastin-like proteins designed to support neural regeneration through a combination of cell adhesion and cell-induced degradation and remodeling. Through use of a modular protein-design strategy, a range of biomaterials is created that allows independent tuning over the initial elastic modulus, degradation rate, cell adhesivity, and neurite outgrowth. By combining these engineered proteins into composite structures, biomaterials are created with 3D patterns that emerge over time in response to cell-secreted enzymes. These dynamic 3D structures enable the delivery of multiple drugs with precise spatial and temporal resolution and also enable the design of biomaterials that adapt to changing scaffold needs. PMID: 19964779 [PubMed - in process] |
| Controlling cellular biomechanics of human mesenchymal stem cells.
December 8, 2009 at 7:05 am
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| | Controlling cellular biomechanics of human mesenchymal stem cells. Conf Proc IEEE Eng Med Biol Soc. 2009;1:2090-3 Authors: Titushkin IA, Cho MR The therapeutic efficacy of human mesenchymal stem cells (hMSCs) depends on proper characterization and control of their unique biological, mechanical and physicochemical properties. For example, cellular biomechanics and environmental mechanical cues have been shown to critically influence cell commitment to a particular lineage. We characterized biomechanical properties of hMSCs including cytoskeleton elasticity and plasma membrane/cytoskeleton coupling. As expected, during osteogenic differentiation of hMSCs, the cellular biomechanics is remodeled, and such remodeling precedes up-regulation of the osteogenic markers. Further, application of an electrical stimulation modulates the cellular biomechanics and therefore may be used to facilitate stem cell differentiation for stem cell-based tissue engineering. PMID: 19964578 [PubMed - in process] |
| Differentiation of pluripotent stem cells on multiwalled carbon nanotubes.
December 8, 2009 at 7:05 am
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| | Differentiation of pluripotent stem cells on multiwalled carbon nanotubes. Conf Proc IEEE Eng Med Biol Soc. 2009;1:6022-5 Authors: Holy J, Perkins E, Yu X This paper studies the adhesion, growth, and differentiation of stem cells on carbon nanotube matrices. Glass coverslips were coated with multiwalled carbon nanotube (MWNT) thin films using layer-by-layer self-assembling techniques. Pluripotent P19 mouse embryonal carcinoma stem cells were seeded onto uncoated or MWNT-coated coverslips, and either maintained in an undifferentiated state or induced to differentiate by the addition of retinoic acid. We found that cell adhesion was increased on the MWNT-coated surfaces, and that the expression patterns of some differentiation markers were altered in cells grown on MWNTs. The results suggest that MWNTs will be useful in directing pluripotent stem cell differentiation for tissue engineering purposes. PMID: 19964415 [PubMed - in process] |
| Cell-matrix mechanobiology: Applications to brain tumors and design of tissue engineering scaffolds.
December 8, 2009 at 7:05 am
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| | Cell-matrix mechanobiology: Applications to brain tumors and design of tissue engineering scaffolds. Conf Proc IEEE Eng Med Biol Soc. 2009;1:3350-2 Authors: Kumar S It is becoming increasingly clear that mechanical and other biophysical signals from the extracellular matrix (ECM) can powerfully influence a wide variety of fundamental cell behaviors, including proliferation, differentiation, death, and motility. This concept has significant implications both for understanding the pathophysiology of disease and the design of biointerfaces found in cellular microdevices and tissue engineering platforms. Here we briefly review recent progress from our laboratory in investigating the role of ECM-derived mechanical signals in the specific context of two systems: The growth and spread of malignant brain tumors and the design of microscale cardiac tissue engineering systems. In both cases, mechanical signals encoded in the ECM govern motility, mechanics, and/or proliferation in profound and unexpected ways and rely upon the cell's reciprocal ability to generate contractile force through myosin and its molecular regulators. PMID: 19964076 [PubMed - in process] |
| Characterizing the effects of aligned collagen fibers and ascorbic acid derivatives on behavior of rabbit corneal fibroblasts.
December 8, 2009 at 7:05 am
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| | Characterizing the effects of aligned collagen fibers and ascorbic acid derivatives on behavior of rabbit corneal fibroblasts. Conf Proc IEEE Eng Med Biol Soc. 2009;1:4242-5 Authors: Phu D, Orwin EJ The cornea is responsible for functional optical activity of the mammalian eye, as it must remain transparent in order to focus light onto the retina. Corneal disease is the second leading cause worldwide of vision loss [1]. Human donor tissue transplantation in the cornea is associated with problems such as immunorejection and recurring graft failures [1]. Tissue engineering offers a promising alternative to using human donor tissues in treating corneal diseases. A viable tissue-engineered cornea must be mechanically resilient to protect the fragile intraocular components of the eye, and optically transparent to refract light onto the retina. In the native cornea, transparency is maintained by both the cells in the stromal layer and the high organization of the extracellular matrix (ECM). This study aims to combine the effects of aligned collagen fibers and ascorbic acid derivatives to control corneal fibroblast behavior to not only express the appropriate proteins, but also to deposit aligned, small diameter collagen fibers that resemble the highly organized structure of the natural ECM. Results from this study suggest that the combined effect of an aligned scaffolding material and ascorbic acid supplements can create a cell-matrix construct that both downregulates expression of the light scattering protein a-smooth muscle actin (alpha-sma) and supports an increased number of cell layers. PMID: 19963815 [PubMed - in process] |
| Design and implementation of a two-dimensional inkjet bioprinter.
December 8, 2009 at 7:05 am
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| | Design and implementation of a two-dimensional inkjet bioprinter. Conf Proc IEEE Eng Med Biol Soc. 2009;1:6001-5 Authors: Pepper ME, Parzel CA, Burg T, Boland T, Burg KJ, Groff RE Tissue engineering has the potential to improve the current methods for replacing organs and tissues and for investigating cellular process within the scope of a tissue test system. Bioprinting technology can aid in the difficult task of arranging live mammalian cells and biomaterials in viable structures for tissue engineering purposes. This paper describes a system, based on HP26 series print cartridge technology, capable of precisely depositing multiple cell types in precise patterns. The paper discusses the research, design, and implementation of the printing system, which permits control of droplet firing parameters, including firing energy, speed, and spacing. The results demonstrate the system's fine patterning ability of viable cells, including two-dimensional patterned co-cultures of two cell types. The system has been specifically designed with the flexibility to be extended to print more than two cell types and/or materials simultaneously and to layer printed patterns to form three-dimensional constructs. With these features, the printing system will serve as the foundation for a biofabrication system capable of three-dimensional cell co-cultures, i.e. tissue test systems. PMID: 19963663 [PubMed - in process] |
| Tuning hydrogel properties for applications in tissue engineering.
December 8, 2009 at 7:05 am
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| | Tuning hydrogel properties for applications in tissue engineering. Conf Proc IEEE Eng Med Biol Soc. 2009;1:2094-6 Authors: Khetan S, Chung C, Burdick JA Biomaterial design is an important component towards tissue engineering applications. There are many parameters that may be adjusted including physical properties (i.e., degradation and mechanics) and chemical properties (e.g., adhesion and cellular interactions). These design components may dictate the success or failure of a tissue engineering approach. Our group is particularly interested in the use of swollen hydrogels as cell carriers. One material that is used to fabricate hydrogels is hyaluronic acid (HA), which is found in many tissues in the body. Here, we show the control over hydrogel degradation, both in the bulk and locally to cells to control both the distribution of extracellular matrix by cells and whether or not a cell spreads in the hydrogels. These signals are important in the final structure and mechanical properties of engineered tissues, and potentially the differentiation of encapsulated stem cells. PMID: 19963530 [PubMed - in process] |
| Bioactive nanofibers for fibroblastic differentiation of mesenchymal precursor cells for ligament/tendon tissue engineering applications.
December 8, 2009 at 7:05 am
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| | Bioactive nanofibers for fibroblastic differentiation of mesenchymal precursor cells for ligament/tendon tissue engineering applications. Differentiation. 2009 Dec 4; Authors: Sahoo S, Ang LT, Cho-Hong Goh J, Toh SL Mesenchymal stem cells and precursor cells are ideal candidates for tendon and ligament tissue engineering; however, for the stem cell-based approach to succeed, these cells would be required to proliferate and differentiate into tendon/ligament fibroblasts on the tissue engineering scaffold. Among the various fiber-based scaffolds that have been used in tendon/ligament tissue engineering, hybrid fibrous scaffolds comprising both microfibers and nanofibers have been recently shown to be particularly promising. With the nanofibrous coating presenting a biomimetic surface, the scaffolds can also potentially mimic the natural extracellular matrix in function by acting as a depot for sustained release of growth factors. In this study, we demonstrate that basic fibroblast growth factor (bFGF) could be successfully incorporated, randomly dispersed within blend-electrospun nanofibers and released in a bioactive form over 1 week. The released bioactive bFGF activated tyrosine phosphorylation signaling within seeded BMSCs. The bFGF-releasing nanofibrous scaffolds facilitated BMSC proliferation, upregulated gene expression of tendon/ligament-specific ECM proteins, increased production and deposition of collagen and tenascin-C, reduced multipotency of the BMSCs and induced tendon/ligament-like fibroblastic differentiation, indicating their potential in tendon/ligament tissue engineering applications. PMID: 19963313 [PubMed - as supplied by publisher] | | | 
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