4/16 pubmed: "regenerative medici...

Please add updates@feedmyinbox.com to your address book to make sure you receive these messages in the future. pubmed: "regenerative medici... Introducing dip pen nanolithography as a tool for controlling stem cell behaviour: unlocking the potential of the next generation of smart materials in regenerative medicine. April 15, 2010 at 6:08 AM Introducing dip pen nanolithography as a tool for controlling stem cell behaviour: unlocking the potential of the next generation of smart materials in regenerative medicine. Lab Chip. 2010 Apr 14; Authors: Curran JM, Stokes R, Irvine E, Graham D, Amro NA, Sanedrin RG, Jamil H, Hunt JA Reproducible control of stem cell populations, regardless of their original source, is required for the true potential of these cells to be realised as medical therapies, cell biology research tools and in vitro assays. To date there is a lack of consistency in successful output when these cells are used in clinical trials and even simple in vitro experiments, due to cell and material variability. The successful combination of single chemistries in nanoarray format to control stem cell, or any cellular behaviour has not been previously reported. Here we report how homogenously nanopatterned chemically modified surfaces can be used to initiate a directed cellular response, particularly mesenchymal stem cell (MSC) differentiation, in a highly reproducible manner without the need for exogenous biological factors and heavily supplemented cell media. Successful acquisition of these data should lead to the optimisation of cell selective properties of materials, further ! enhancing the role of nanopatterned substrates in cell biology and regenerative medicine. The successful design and comparison of homogenously molecularly nanopatterned surfaces and their direct effect on human MSC adhesion and differentiation are reported in this paper. Planar gold surfaces were patterned by dip pen nanolithography (DPN(R)) to produce arrays of nanodots with optimised fixed diameter of 70 nanometres separated by defined spacings, ranging from 140 to 1000 nm with terminal functionalities of simple chemistries including carboxyl, amino, methyl and hydroxyl. These nanopatterned surfaces exhibited unprecedented control of initial cell interactions and subsequent control of cell phenotype and offer significant potential for the future. PMID: 20390207 [PubMed - as supplied by publisher]   Binding and release characteristics of insulin-like growth factor-1 from a collagen-GAG scaffold. April 15, 2010 at 6:08 AM Binding and release characteristics of insulin-like growth factor-1 from a collagen-GAG scaffold. Tissue Eng Part C Methods. 2010 Apr 13; Authors: Mullen LM, Best SM, Brooks RA, Ghose S, Gwynne JH, Wardale J, Rushton N, Cameron R Tissue engineering is a promising technique for cartilage repair but in order to optimise novel scaffolds prior to clinical trials it is necessary determine their characteristics for binding and release of growth factors. Towards this goal, a novel, porous collagen-GAG scaffold was loaded with a range of concentrations of insulin-like growth factor-1 (IGF-1) to evaluate its potential as a controlled delivery device. The kinetics of IGF-1 adsorption and release from the scaffold was demonstrated using radiolabelled IGF-1. Adsorption was rapid, and was approximately proportional to the loading concentration. Ionic bonding contributed to this interaction. IGF-1 release was studied over 14 days to compare the release profiles from different loading groups. Two distinct phases occurred; firstly a burst release of up to 44% within the first 24 h, then a slow, sustained release (13-16%) was observed from days 1-14. When the burst release was subtracted the relative perce! ntage of remaining IGF-1 released was similar for all loading groups and broadly followed t1/2 kinetics until approximately day 6. Scaffold cross-linking using dehydrothermal treatment did not affect IGF-1 adsorption or release. Bioactivity of released IGF-1 was confirmed by seeding scaffolds (pre-adsorbed with unlabelled IGF-1) with human osteoarthritic chondrocytes and demonstrating increased proteoglycan production in vitro. PMID: 20388039 [PubMed - as supplied by publisher]   Mimicking natural dentin using bioactive nanohybrid scaffolds for dentinal tissue engineering. April 15, 2010 at 6:08 AM Mimicking natural dentin using bioactive nanohybrid scaffolds for dentinal tissue engineering. Tissue Eng Part A. 2010 Apr 13; Authors: Vallés-Lluch A, Novella-Maestre E, Sancho-Tello M, Monleon Pradas M, Gallego Ferrer G, Carda C Synthetic materials mimicking the internal porous structure of natural dentin were prepared as nanohybrid matrix scaffolds made of poly(ethyl methacrylate-co-hydroxyethyl acrylate), pure and with a sol-gel derived interpenetrated silica nanophase, with aligned tubular pores in the micrometer range typical of dentinal tissue. Some of them were internally coated with a layer of hydroxyapatite by immersion in simulated body fluid. Their physico-chemical and mechanical properties were investigated. The different types of scaffolds were implanted subcutaneously into immunocompromised nude mice for 4, 6 and 8 weeks and their biological response were analyzed. Optical microscopy was employed to study the scaffold structure and neovascularization. Cells origin, inflammation and macrophagic responses were evaluated by optical microscopy, immunohistochemistry and transmission electron microscopy. The scaffold ultrastructural pattern imitates dentinal histological structure.! The materials allowed cell colonization and neoangiogenesis. These biomaterials were colonized by murine cells fenotypically different to those of dermal connective tissue, showing structural differentiations. Colonization and viability were improved by the use of mineralized interphases, which showed a cellular distribution resembling a neodentinal pattern. Invasion of the scaffold tubules by single odontoblast-like processes was ascertained both in the non-coated and coated scaffolds. Such materials thus seem promising in tissue engineering strategies for dentin regeneration. PMID: 20388038 [PubMed - as supplied by publisher]   Umbilical cord stem cell seeding on fast-resorbable calcium phosphate bone cement. April 15, 2010 at 6:08 AM Umbilical cord stem cell seeding on fast-resorbable calcium phosphate bone cement. Tissue Eng Part A. 2010 Apr 13; Authors: Xu H, Zhao L, Detamore MS, Takagi S, Chow LC Tissue engineering offers immense promise for bone regeneration. Human umbilical cord mesenchymal stem cells (hUCMSCs) can be collected without invasive procedures required for bone marrow MSCs. The objective of this study was to investigate the physical properties and the differentiation capacity of hUCMSCs on calcium phosphate cement (CPC) scaffolds with improved dissolution/resorption rates. CPC consisted of tetracalcium phosphate (TTCP) and dicalcium phosphate-anhydrous (DCPA), with various TTCP/DCPA ratios. At 1/3 ratio, CPC had a dissolution rate 40% faster than CPC control at 1/1. The faster-resorbable CPC had strength and modulus similar to CPC control. Their strength and modulus exceeded the reported values for cancellous bone, and were much higher than those of hydrogels and injectable polymers for cell delivery. hUCMSCs attached to the nano-apatitic CPC and proliferated rapidly. hUCMSCs differentiated into the osteogenic lineage, with significant increa! ses in alkaline phosphatase activity, osteocalcin, collagen I, and osterix gene expressions. In conclusion, in this study we reported that hUCMSCs attaching to CPC with high dissolution/resorption rate showed excellent proliferation and osteogenic differentiation. hUCMSCs delivered via high-strength CPC have the potential to be an inexhaustible and low-cost alternative to the gold-standard hBMSCs. These results may broadly impact stem cell-based tissue engineering. PMID: 20388037 [PubMed - as supplied by publisher]   Photocrosslinkable Hyaluronan-Gelatin Hydrogels for Two-Step Bioprinting. April 15, 2010 at 6:08 AM Photocrosslinkable Hyaluronan-Gelatin Hydrogels for Two-Step Bioprinting. Tissue Eng Part A. 2010 Apr 13; Authors: Skardal A, Zhang J, McCoard L, Xu X, Oottamasathien S, Prestwich G Bioprinting by the co-deposition of cells and biomaterials is constrained by the availability of printable materials. Herein we describe a novel macromonomer, a new two-step photocrosslinking strategy, and the use of a simple rapid prototyping system to print a proof-of-concept tubular construct. First, we synthesized the methacrylated ethanolamide derivative of gelatin (GE-MA). Second, partial photochemical co-crosslinking of GE-MA with methacrylated HA (HA-MA) gave an extrudable gel-like fluid. Third, the new HA-MA:GE-MA hydrogels were biocompatible, supporting cell attachment and proliferation of HepG2 3CA, Int-407, and NIH3T3 cells in vitro. Moreover, hydrogels injected subcutaneously in nude mice produced no inflammatory response. Fourth, using the Fab@Home printing system, we printed a tubular tissue construct. The partially crosslinked hydrogels were extruded from a syringe into a designed base layer, and irradiated again to create a firmer structure. The c! omputer-driven protocol was iterated to complete a cellularized tubular construct with a cell-free core and a cell-free structural halo. Cells encapsulated within this printed construct were viable in culture, and gradually remodeled the synthetic extracellular matrix (ECM) environment to a naturally secreted ECM. This two-step photocrosslinkable biomaterial addresses an unmet need for printable hydrogels useful in tissue engineering. PMID: 20387987 [PubMed - as supplied by publisher]   Mechanical Stimulation Mediates Gene Expression in MC3T3 Osteoblastic Cells Differently in 2D and 3D Environments. April 15, 2010 at 6:08 AM Mechanical Stimulation Mediates Gene Expression in MC3T3 Osteoblastic Cells Differently in 2D and 3D Environments. J Biomech Eng. 2010 Apr;132(4):041005 Authors: Barron MJ, Tsai CJ, Donahue SW Successful bone tissue engineering requires the understanding of cellular activity in three-dimensional (3D) architectures and how it compares to two-dimensional (2D) architecture. We developed a perfusion culture system that utilizes fluid flow to mechanically load a cell-seeded 3D scaffold. This study compared the gene expression of osteoblastic cells in 2D and 3D cultures, and the effects of mechanical loading on gene expression in 2D and 3D cultures. MC3T3-E1 osteoblastlike cells were seeded onto 2D glass slides and 3D calcium phosphate scaffolds and cultured statically or mechanically loaded with fluid flow. Gene expression of OPN and FGF-2 was upregulated at 24 h and 48 h in 3D compared with 2D static cultures, while collagen 1 gene expression was downregulated. In addition, while flow increased OPN in 2D culture at 48 h, it decreased both OPN and FGF-2 in 3D culture. In conclusion, gene expression is different between 2D and 3D osteoblast cultures under sta! tic conditions. Additionally, osteoblasts respond to shear stress differently in 2D and 3D cultures. Our results highlight the importance of 3D mechanotransduction studies for bone tissue engineering applications. PMID: 20387968 [PubMed - in process]   [The possibility of regenerative medicine for myocardial infarction and ischemic cardiomyopathy by using several stem cells] April 15, 2010 at 6:08 AM [The possibility of regenerative medicine for myocardial infarction and ischemic cardiomyopathy by using several stem cells] Nippon Rinsho. 2010 Apr;68(4):731-6 Authors: Egashira T, Fukuda K Improvement of therapy for severe heart failure due to ischemic cardiomyopathy and myocardial infarction is an important issue of cardiovascular medicine. Recently, regenerative therapy is seemed to be one of the possible ways to solve this problem. There are many potential cell sources for regenerative medicine, such as skeletal myocytes, bone marrow stem cells, endothelial progenitor cells, cardiac progenitor cells and embryonic stem (ES) cells. ES cells are highly proliferative and suitable for mass production and many protocols have been established to ensure selective cardiomyocyte induction. Current studies have successfully generated induced pluripotent stem(iPS) cells from human fibroblasts by the gene transfer of 4 transcription factors that are strongly expressed in ES cells: Oct3/4, Sox2, Klf4 and c-Myc. iPS cells can differentiate into all 3 germ layer-derived cells, including cardiomyocytes as same as ES cells and are syngeneic, indicating that they c! an become an ideal cell source for regenerative medicine. PMID: 20387569 [PubMed - in process]   [Myocardial regeneration for heart failure] April 15, 2010 at 6:08 AM [Myocardial regeneration for heart failure] Nippon Rinsho. 2010 Apr;68(4):719-25 Authors: Sawa Y We had examined the efficacy of stem cell therapy using tissue engineered sheet technique compared to needle injection. This technique has advantages such as the ability for treatment to large area, and less invasive for host heart such as lethal arrhythmia. In vivo, implantation of autologous myoblast sheet had improved cardiac function of ischemic or dilated cardiomyopathy models using rat, hamster, canine and porcine models. We also showed that myoblast sheets provided various factors inducing angiogenesis, hematopoietic cell recruitment and anti-apoptosis, following anti remodeling. Thus, after approved by IRB of our institution, we have started the clinical trial of myoblast sheet implantation for DCM patients, and assessed the feasibility and efficacy for the first patient. In this patient, any sequelae including arrhythmia have not occurred after implantation, and the cardiac function showed recovery. Thus, stem cell sheet implantation could be safe and eli! gible as cardiac regeneration therapy. PMID: 20387567 [PubMed - in process]   [Research and development for treating devastating corneal diseases] April 15, 2010 at 6:08 AM [Research and development for treating devastating corneal diseases] Nippon Ganka Gakkai Zasshi. 2010 Mar;114(3):161-99; discussion 200-1 Authors: Kinoshita S In order to develop new therapeutic modalities for corneal diseases, it is essential to combine cutting-edge translational research based upon liberal original ideas obtained from clinical experience with state-of-the-art basic science and technology. Here, I describe seven important research projects on which our group has been working. 1. Elucidation of the pathogenesis in gelatinous drop-like corneal dystrophy(GDLD). Due to loss of function of the tumor-associated calcium signal transducer 2 (TACSTD2), a responsible gene for this dystrophy, tight-junction-related proteins cease to function, resulting in severe corneal epithelial barrier impairment. As a result, various proteins contained in tear fluid continuously penetrate into the corneal stroma, promoting the development of massive amyloid deposits. 2. The development of cultivated mucosal epithelial transplantation: A landmark surgery, involving the transplantation of cultivated mucosal epithelial cells fro! m in vitro to in vivo, now recognized as the next generation of ocular surface reconstruction. We began performing cultivated allocorneal epithelial transplantations in 1999, and cultivated auto-corneal and auto-oral mucosal epithelial transplantations in 2002. These proved to be very effective in the reconstruction of both the corneal surface and the conjunctival fornix. 3. Elucidation of the pathogenesis of Stevens-Johnson syndrome: Studies have shown that there is a close relationship between corneal epithelial stem cell loss and the associated degree of visual impairment. We discovered that a steroid pulse therapy at the acute phase aimed at minimizing stem cell loss is very effective in restoring visual acuity. This implies that inhibition of the cytokine storm is essential for the treatment of acute-phase Stevens-Johnson syndrome. The innate immunity abnormality seems to be heavily involved at the onset of this devastating disease. 4. Elucidation of the involvement of! EP3 and toll like receptor 3 (TLR3) in inflammatory ocular su! rface re actions : We discovered that EP3, one of the prostanoid receptors expressed by ocular surface epithelium, has a dramatic inhibitory effect on ocular surface inflammation in a mouse model. Since EP3 is also expressed in human ocular surface epithelium, and since abnormality of its single nucleotide polymorphisms (SNPs) is involved in some ocular surface inflammatory diseases, we theorized that an allergic reaction may be negatively regulated by EP3 which is predominantly expressed by the ocular surface epithelium. Our findings show that this is similarly true for TLR3, which, conversely, upregulates ocular surface inflammation. 5. Functional regulation of the ocular surface epithelium: Our findings show that intracellular glutathione (GSH) content in the ocular surface epithelium regulates its intracellular redox state. For instance, the GSH content of the conjunctival epithelium decreases in dry eye diseases, yet recovers after the surgical insertion of a punctal plug. Since! various amino acids are also heavily involved in the regulation of cellular functions, we investigated the profile of amino acids contained in tear fluids. Our results indicate that there is a marked difference in amino acid profiles between tear fluids and plasma. Furthermore, we found that several amino acids are up-regulated in inflamed eyes, probably due to an oxidative redox response. 6. The development of new therapeutic modalities for corneal edema: We are developing a new therapeutic modality of cultivated corneal endothelial transplantation using methods based on regenerative medicine. For instance, our findings show that cultivated corneal endothelial sheet transplantation in monkeys maintains corneal transparency for at least four years after transplantation. The supplementation of a Rho kinase (ROCK) inhibitor in the culture media produces an excellent result in culturing human corneal endothelium, maintaining a normal-looking endothelial cell morphology. The u! se of a ROCK inhibitor, both for cultivated endothelial cell i! njection into the anterior chamber and for use as a topical application, may prove to be a potential tool for the treatment of corneal endothelial dysfunction. 7. The development of a new type of tear function test : The results of our investigations show that the time-dependent changes of tear film lipid layer (TFLL) spread are compatible with the Voigt model of viscoelasticity, and that the initial velocity of the TFLL spread after a blink decreases in proportion to the decrease in tear volume. Thus, a lipid-layer analysis will become an important tear analysis tool. The above are projects representing the way we believe new treatments for severe corneal diseases are heading. PMID: 20387535 [PubMed - in process]   A nanodevice for rapid modulation of proliferation, apoptosis, invasive ability, and cytoskeletal reorganization in cultured cells. April 15, 2010 at 1:08 AM A nanodevice for rapid modulation of proliferation, apoptosis, invasive ability, and cytoskeletal reorganization in cultured cells. Lab Chip. 2010 May 7;10(9):1189-98 Authors: Hung YC, Pan HA, Tai SM, Huang GS We have fabricated a nanodevice composed of a matrix of nine nanodot arrays with various dot sizes, ranging from a flat surface to 10 nm, 50 nm, 100 nm, and 200 nm arrays. HELA, C33A, ES2, PA-1, TOV-112D, TOV-21G, MG63, and NIH-3T3 cells were seeded onto the device and cultured for three days. To evaluate the size-dependent effect of nanodot arrays on cell growth, indices corresponding to cell proliferation, apoptosis, cell adhesion, and cytoskeletal organization were defined. VD(50) is defined as the diameter of nanodots on which 50% of the cell population remains viable. AD(50) is defined as the diameter of nanodots on which 50% of the cell population appears to have an apoptosis-like morphology. FD(50) is the diameter of nanodots that promotes the formation of 50% of the focal adhesions compared to cells grown on a flat surface. CD(50) is defined as the diameter of nanodots on which cells have half the amount of microfilament bundles compared to cells grown on ! a flat surface. We were able to distinguish between the invasive ability of HELA versus later-staged C33A cells. Ovarian cancer cell lines (ES2, PA-1, TOV-112D, and TOV-21G) also exhibited differential growth parameters that are associated with cell type, grade, and stage. Modulation of the growth of MG63 cells was also achieved. More broadly, we have established a platform that can be used to assess basic parameters of cell growth. A simplified fabrication process ensures mass production and lowers cost. According to our results, the device is capable of distinguishing among cancer cell lines at various stages and also provides basic design parameters for artificial implants. Our device will serve as a convenient and fast tool for tissue engineering and cancer treatment. PMID: 20390139 [PubMed - in process]   This email was sent to agupta1213+termsc@gmail.com.  Account Login Don't want to receive this feed any longer? Unsubscribe here This email was carefully delivered by Feed My Inbox. 230 Franklin Road Suite 814 Franklin, TN 37064