|  |  |  | | | | | TE-RegenMed-StemCell feed | | | | | | | | | | | | | | | | | | | Human peripheral nerve-derived scaffold for tissue-engineered nerve grafts: histology and biocompatibility analysis. J Biomed Mater Res B Appl Biomater. 2011 Jan;96(1):25-33 Authors: Yang LM, Liu XL, Zhu QT, Zhang Y, Xi TF, Hu J, He CF, Jiang L Human acellular nerve grafts (ANGs) have been rarely used to construct tissue-engineered nerves compared to the animal-derived ANGs, and their potential clinical applications were relatively unknown. In this study, it was aimed to investigate the structure and components of a scaffold derived from human peripheral nerve and evaluate its biocompatibility. The human peripheral nerves were processed to prepare the scaffolds by chemical extraction. Light and electron microscopy were carried out to analyze scaffold structure and components. The analysis of cytotoxicity, hemolysis, and skin sensitization were performed to evaluate their biocompatibility. It was shown that Schwann cells and axons, identified by S-100 and neurofilament (NF) expression, were absent, and the scaffolds were cell-free and rich in collagen-I and laminin whose microarchitecture was similar to the fibrous framework of human peripheral nerves. It was revealed from biocompatibility tests that the scaffolds had very mild cytotoxicity and hemolysis, whereas skin sensitization was not observed. The constructed human peripheral nerve-derived scaffolds with well biocompatibility for clinical practice, which were cell-free and possess the microstructure and extracellular matrix (ECM) of a human nerve, might be an optimal scaffold for tissue-engineered nerve grafts in human. PMID: 21053261 [PubMed - indexed for MEDLINE] | | | | | | | | | | | | | | | | | | | | | | | | | Ectopic osteochondral formation of biomimetic porous PVA-n-HA/PA6 bilayered scaffold and BMSCs construct in rabbit. J Biomed Mater Res B Appl Biomater. 2011 Jan;96(1):9-15 Authors: Qu D, Li J, Li Y, Khadka A, Zuo Y, Wang H, Liu Y, Cheng L In this work, the novel poly vinyl alcohol/gelatin-nano-hydroxyapatite/polyamide6 (PVA-n-HA/PA6) bilayered scaffold with biomimetic properties for articular cartilage and subchondral bone is developed. Furthermore, when these osteochondral scaffolds were seeded with induced bone mesenchymal stem cells (BMSCs) and implanted at ectopic sites, showed the potential for an engineered cartilage tissue and the corresponding subchondral bone. BMSCs were expanded in vitro and induced to chondrogenic or osteogenic potential by culturing in suitable media for 14 days. Subsequently, these induced cells were seeded into PVA-n-HA/PA6 separately, and the constructs were implanted into the rabbit muscle pouch for upto 12 weeks. Ectopic neocartilage formation in the PVA layer and reconstitution of the subchondral bone which remained confined within the n-HA/PA6 layer with the alteration of the cellular phenotype were identified with Masson's trichrome stain. Simultaneously, the RT-PCR results confirmed the expression of specific extracellular matrix (ECM) markers for cartilaginous tissue, such as collagen type II (Col-II), or alternatively, markers for osteoid tissue, such as collagen type I (Col-I) at the corresponding layers. During ectopic implantation, the underlying subchondral bone layer was completely integrated with the cartilage layer. The result from the ectopic osteochondral scaffolds implantation suggests that PVA-n-HA/PA6 with induced BMSCs is a possible substitute with potential in cartilage repair strategies. PMID: 20967773 [PubMed - indexed for MEDLINE] | | | | | | | | | | | | | | | | | | | | | | | | | Biophysical characterization of ovine forestomach extracellular matrix biomaterials. J Biomed Mater Res B Appl Biomater. 2011 Jan;96(1):67-75 Authors: Floden EW, Malak SF, Basil-Jones MM, Negron L, Fisher JN, Lun S, Dempsey SG, Haverkamp RG, Ward BR, May BC Ovine forestomach matrix (OFM) is a native and functional decellularized extracellular matrix biomaterial that supports cell adhesion and proliferation and is remodeled during the course of tissue regeneration. Small angle X-ray scattering demonstrated that OFM retains a native collagen architecture (d spacing = 63.5 ± 0.2 nm, orientation index = 20°). The biophysical properties of OFM were further defined using ball-burst, uniaxial and suture retention testing, as well as a quantification of aqueous permeability. OFM biomaterial was relatively strong (yield stress = 10.15 ± 1.81 MPa) and elastic (modulus = 0.044 ± 0.009 GPa). Lamination was used to generate new OFM-based biomaterials with a range of biophysical properties. The resultant multi-ply OFM biomaterials had suitable biophysical characteristics for clinical applications where the grafted biomaterial is under load. PMID: 21053262 [PubMed - indexed for MEDLINE] | | | | | | | | | | | | | | | | | | | | | | | | | Induced pluripotent stem cells: developmental biology to regenerative medicine. Nat Rev Cardiol. 2010 Dec;7(12):700-10 Authors: Nelson TJ, Martinez-Fernandez A, Terzic A Nuclear reprogramming of somatic cells with ectopic stemness factors to bioengineer pluripotent autologous stem cells signals a new era in regenerative medicine. The study of developmental biology has provided a roadmap for cardiac differentiation from embryonic tissue formation to adult heart muscle rejuvenation. Understanding the molecular mechanisms of stem-cell-derived cardiogenesis enables the reproducible generation, isolation, and monitoring of progenitors that have the capacity to recapitulate embryogenesis and differentiate into mature cardiac tissue. With the advent of induced pluripotent stem (iPS) cell technology, patient-specific stem cells provide a reference point to systematically decipher cardiogenic differentiation through discrete stages of development. Interrogation of iPS cells and their progeny from selected cohorts of patients is an innovative approach towards uncovering the molecular mechanisms of disease. Thus, the principles of cardiogenesis can now be applied to regenerative medicine in order to optimize personalized therapeutics, diagnostics, and discovery-based science for the development of novel clinical applications. PMID: 20956984 [PubMed - indexed for MEDLINE] | | | | | | | | | | | | | | | | | | | | | | | | | The regulation of differentiation in mesenchymal stem cells. Hum Gene Ther. 2010 Oct;21(10):1226-38 Authors: Augello A, De Bari C Mesenchymal stromal/stem cells (MSCs) are a population of stromal cells present in the bone marrow and most connective tissues, capable of differentiation into mesenchymal tissues such as bone and cartilage. MSCs are attractive candidates for biological cell-based tissue repair approaches because of their extensive proliferative ability in culture while retaining their mesenchymal multilineage differentiation potential. In addition to its undoubted scientific interest, the prospect of monitoring and controlling MSC differentiation is a crucial regulatory and clinical requirement. Hence, the molecular regulation of MSC differentiation has been extensively studied. Most of the studies are in vitro, because the identity of MSCs in their tissues of origin in vivo remains undefined. This review addresses the current knowledge of the molecular basis of differentiation of cultured MSCs, with a particular focus on chondrogenesis and osteogenesis. Building on the information coming from developmental biology studies of embryonic skeletogenesis, several signaling pathways and transcription factors have been investigated and shown to play critical roles in MSC differentiation. In particular, the Wnt and transforming growth factor-β/bone morphogenetic protein signaling pathways are well known to modulate in MSCs the molecular differentiation into cartilage and bone. Relevant to the emerging concept of stem cell niches is the demonstration that physical factors can also participate in the regulation of MSC differentiation. Knowledge of the regulation of MSC differentiation will be critical in the design of three-dimensional culture systems and bioreactors for automated bioprocessing through mathematical models applied to systems biology and network science. PMID: 20804388 [PubMed - indexed for MEDLINE] | | | | | | | | | | | | | | | | | | | | | | | | | Virally and physically transgenized equine adipose-derived stromal cells as a cargo for paracrine secreted factors. BMC Cell Biol. 2010;11:73 Authors: Donofrio G, Capocefalo A, Franceschi V, Morini G, Del Bue M, Conti V, Cavirani S, Grolli S Adipose-Derived Stromal Cells have been shown to have multiple lineage differentiation properties and to be suitable for tissues regeneration in many degenerative processes. Their use has been proposed for the therapy of joint diseases and tendon injuries in the horse. In the present report the genetic manipulation of Equine Adipose-Derived Stromal Cells has been investigated. PMID: 20863390 [PubMed - indexed for MEDLINE] | | | | | | | | | |  | |  | |  |
No comments:
Post a Comment