|  |  |  | | | | | TE-RegenMed-StemCell feed | | | | | | | | | | | | | | | | | | Three top leaders of the California stem cell agency have come up with a plan that they hope will allow CIRM to avoid the wrath of the public when its new chairman is paid a salary that could be seven times the income of an entire, typical California household.
The proposal, which has not been laid out in public, was advanced in a March 17 letter sent to the four state officials who have | | | | | | | | | | | | | | | | | | | | | | | | | Effects of laminin blended with chitosan on axon guidance on patterned substrates. Biofabrication. 2010 Dec;2(4):045002 Authors: Zhu N, Li MG, Guan YJ, Schreyer DJ, Chen XB Axon guidance is a crucial consideration in the design of tissue scaffolds used to promote nerve regeneration. Here we investigate the combined use of laminin (a putative axon adhesion and guidance molecule) and chitosan (a leading candidate base material for the construction of scaffolds) for promoting axon guidance in cultured adult dorsal root ganglion (DRG) neurons. Using a dispensing-based rapid prototyping (DBRP) technique, two-dimensional grid patterns were created by dispensing chitosan or laminin-blended chitosan substrate strands oriented in orthogonal directions. In vitro experiments illustrated DRG neurites on these patterns preferentially grew upon and followed the laminin-blended chitosan pathways. These results suggest that an orientation of neurite growth can be achieved in an artificially patterned substrate by creating selectively biofunctional pathways. The DBRP technique may provide improved strategies for the use of biofunctional pathways in the design of three-dimensional scaffolds for guidance of nerve repair. PMID: 21076186 [PubMed - indexed for MEDLINE] | | | | | | | | | | | | | | | | | | | | | | | | | Hyaluronic acid and Dextran based Semi-IPN Hydrogels as Biomaterials for Bioprinting. Biomacromolecules. 2011 Mar 22; Authors: Pescosolido L, Schuurman W, Malda J, Matricardi P, Alhaique F, Coviello T, van Weeren PR, Dhert WJ, Hennink WE, Vermonden T Bioprinting is a recent technology in tissue engineering used for the design of porous constructs through layer-by-layer deposition of cell-laden material. This technology would benefit new biomaterials that can fulfill specific requirements for the fabrication of well-defined three-dimensional (3D) constructs, such as the preservation of cell viability and adequate mechanical properties. We evaluated the suitability of novel semi-interpenetrating network (semi-IPN), based on hyaluronic acid and hydroxyethyl-methacrylate-derivatized dextran (dex-HEMA), to form 3D hydrogel bioprinted constructs. The rheological properties of the solutions allowed proper handling during bioprinting while photopolymerization led to stable constructs of which their mechanical properties matched the wide range of mechanical strengths of natural tissues. Importantly, excellent viability was observed for encapsulated chondrocytes. The results demonstrate the suitability of hyaluronic acid/dex-HEMA semi-IPNs to manufacture bioprinted constructs for tissue engineering. PMID: 21425854 [PubMed - as supplied by publisher] | | | | | | | | | | | | | | | | | | | | | | | | | Human corneal endothelial cell growth on a silk fibroin membrane. Biomaterials. 2011 Mar 20; Authors: Madden PW, Lai JN, George KA, Giovenco T, Harkin DG, Chirila TV Tissue engineering of the cornea could overcome shortages of donor corneas for transplantation and improve quality. Our aim was to grow an endothelial layer on a substratum suitable for transplant. Silkworm (Bombyx mori) fibroin was prepared as 5 μm thick transparent membranes. The B4G12 cell line was used to assess attachment and growth of human corneal endothelial cells on fibroin and compare this with a reference substratum of tissue-culture plastic. To see if cell attachment and proliferation could be improved, we assessed coatings of collagen IV, FNC Coating Mix(®) and a chondroitin sulphate-laminin mixture. All the coatings improved the final mean cell count, but consistently higher cell densities were achieved on a tissue-culture plastic rather than fibroin substratum. Collagen-coated substrata were the best of both groups and collagen-coated fibroin was comparable to uncoated tissue-culture plastic. Only fibroin with collagen coating achieved cell confluency. Primary human corneal endothelial cells were then grown using a sphere-forming technique and when seeded onto collagen-coated fibroin they grew to confluency with polygonal morphology. We report the first successful growth of primary human corneal endothelial cells on coated fibroin as a step in evaluating fibroin as a substratum for the transplantation of tissue-constructs for endothelial keratoplasty. PMID: 21427010 [PubMed - as supplied by publisher] | | | | | | | | | | | | | | | | | | | | | | | | | Thin films of functionalized multiwalled carbon nanotubes as suitable scaffold materials for stem cells proliferation and bone formation. ACS Nano. 2010 Dec 28;4(12):7717-25 Authors: Nayak TR, Jian L, Phua LC, Ho HK, Ren Y, Pastorin G In the field of regenerative medicine, human mesenchymal stem cells envisage extremely promising applications, due to their ability to differentiate into a wide range of connective tissue species on the basis of the substrate on which they grow. For the first time ever reported, we investigated the effects of a thin film of pegylated multiwalled carbon nanotubes spray dried onto preheated coverslips in terms of their ability to influence human mesenchymal stem cells' proliferation, morphology, and final differentiation into osteoblasts. Results clearly indicated that the homogeneous layer of functionalized nanotubes did not show any cytotoxicity and accelerated cell differentiation to a higher extent than carboxylated nanotubes or uncoated coverslips, by creating a more viable microenvironment for stem cells. Interestingly, cell differentiation occurred even in the absence of additional biochemical inducing agents, as evidenced by multiple independent criteria at the transcriptional, protein expression, and functional levels. Taken together, these findings suggest that functionalized carbon nanotubes represent a suitable scaffold toward a very selective differentiation into bone. PMID: 21117641 [PubMed - indexed for MEDLINE] | | | | | | | | | | | | | | | | | | | | | | | | | Airway branching morphogenesis in three dimensional culture. Respir Res. 2010;11:162 Authors: Franzdóttir SR, Axelsson IT, Arason AJ, Baldursson O, Gudjonsson T, Magnusson MK Lungs develop from the fetal digestive tract where epithelium invades the vascular rich stroma in a process called branching morphogenesis. In organogenesis, endothelial cells have been shown to be important for morphogenesis and the maintenance of organ structure. The aim of this study was to recapitulate human lung morphogenesis in vitro by establishing a three dimensional (3D) co-culture model where lung epithelial cells were cultured in endothelial-rich stroma. PMID: 21108827 [PubMed - indexed for MEDLINE] | | | | | | | | | |  | |  | |  |
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