|  |  |  | | | | | TE-RegenMed-StemCell feed | | | | | | | | | | | | | | | | | | | Autologous chondrocyte implantation for treatment of focal cartilage defects in patients age 40 years and older: A matched-pair analysis with 2-year follow-up. Am J Sports Med. 2010 Dec;38(12):2410-6 Authors: Niemeyer P, Köstler W, Salzmann GM, Lenz P, Kreuz PC, Südkamp NP Autologous chondrocyte implantation (ACI) is an accepted surgical treatment in patients with isolated cartilage defects of the knee. Age has been considered as a limiting factor and the technique has not been recommended in patients older than 40 to 50 years. Nevertheless, some more recent studies report satisfying clinical results in middle-aged patients. PMID: 20829417 [PubMed - indexed for MEDLINE] | | | | | | | | | | | | | | | | | | | | | | | | | In vitro biocompatibility of sheath-core cellulose-acetate-based electrospun scaffolds towards endothelial cells and platelets. J Biomater Sci Polym Ed. 2010;21(13):1713-36 Authors: Rubenstein DA, Venkitachalam SM, Zamfir D, Wang F, Lu H, Frame MD, Yin W Typically, tissue-engineered scaffolds mimic the topographical properties of the native extracellular matrix. However, other physical properties, such as the scaffold mechanical stiffness, are not imitated. The purpose of this study was to fabricate scaffolds with improved mechanical properties and investigate their biocompatibility towards endothelial cells and platelets. To enhance mechanical properties, an electrospinning apparatus was developed that fabricates fibers with sheath-core morphologies. Different combinations of cellulose acetate and chitosan were chosen to modulate the mechanical properties of the formed fibers. We hypothesized that mechanically stiffer scaffolds would improve endothelial cell growth and that all scaffolds would be compatible towards endothelial cells and platelets. Endothelial cell-culture conditions were quantified up to 5 days. Migration onto scaffolds was monitored for 10 days. Platelet aggregation, antagonized by thrombin receptor agonist peptide 6, was measured after scaffold incubation. A platelet activation time-course was assessed with the modified prothrombinase assay. As scaffold mechanical stiffness increased, endothelial cell growth within and adhesion to and migration throughout the scaffolds was promoted. Also, scaffolds did not induce platelet aggregation or activation. These results indicate that the mechanical stiffness of engineered scaffolds regulates endothelial cell-culture parameters and that these sheath-core electrospun scaffolds are compatible towards endothelial cells and platelets. PMID: 20537251 [PubMed - indexed for MEDLINE] | | | | | | | | | | | | | | | | | | | | | | | | | Synthesis of multifunctional Fe(3)O(4) core/hydroxyapatite shell nanocomposites by biomineralization. Dalton Trans. 2011 Mar 31; Authors: Huang C, Zhou Y, Tang Z, Guo X, Qian Z, Zhou S Superparamagnetic nanoparticles with surface functional groups (-OH, -COOH and -NH(2)) were modified by in situ deposition of hydroxyapatite (HA) on the materials' surface through the biomineralization process to form Fe(3)O(4) core/hydroxyapatite shell nanocomposites. They possess potential applications as targeted carriers for antitumor drugs and as bone tissue engineering scaffolds by integrating multiple functions into a single nanosystem. PMID: 21455509 [PubMed - as supplied by publisher] | | | | | | | | | | | | | | | | | | | | | | | | | Ethical issues regarding the donation and source of cells for tissue engineering: A European focus group study. Tissue Eng Part B Rev. 2011 Apr 1; Authors: Oerlemans AJ, van den Berg PP, van Leeuwen E, Dekkers WJ This paper is part of the EuroSTEC project, which aims at developing tissue engineering-based treatments for structural disorders present at birth. EuroSTEC is positioned at the intersection of three areas with their own ethical issues: (1) regenerative medicine, (2) research with pregnant women and fetuses, and (3) research with neonates. Because of the link between these three areas in this project, one can expect to be confronted with new ethical challenges. To be able to respond adequately and timely to current and possible future ethical issues, a prospective and anticipatory ethical analysis is essential. To obtain a first impression of the ethical issues that might arise during the different phases of the project, a Delphi method was used. Based on the results of two previous rounds of questionnaires, two topics were selected for discussion in focus groups: ethical issues associated with (1) source of cells and (2) donation. The results could be divided into three clusters: Tissue, Donor and Scientist. Where the former two clusters roughly coincide with the results of the previous rounds, the third subject was entirely new but discussed by both groups: the role of the scientist in the tissue engineering process. PMID: 21453199 [PubMed - as supplied by publisher] | | | | | | | | | | | | | | | | | | | | | | | | | Evaluation of in vitro growth factor treatments on fibrochondrogenesis by synovial membrane cells from osteoarthritic and nonosteoarthritic joints of dogs. Am J Vet Res. 2011 Apr;72(4):500-11 Authors: Warnock JJ, Fox DB, Stoker AM, Cook JL Objective-To determine the in vitro effects of selected growth factors on fibrochondrogenesis by synovial membrane cells from nonosteoarthritic (normal) and osteoarthritic joints of dogs. Animals-5 dogs with secondary osteoarthritis of shoulder or stifle joints and 6 dogs with normal joints. Procedures-Synovial membrane cells were harvested from normal and osteoarthritic joints and cultured in monolayer with or without (control) basic fibroblast growth factor, transforming growth factor-β1, and insulin-like growth factor-1. In the cultured cells, fibrochondrogenesis was measured by use of a real-time reverse transcriptase PCR assay to determine relative expressions of collagen I, collagen II, and aggrecan genes and of 3 genes involved in embryonic chondrogenesis: Sry-type homeobox protein-9 (SOX-9), frizzled-motif associated with bone development (Frzb), and regulator of G-protein signaling-10 (RGS-10). Tissue collagen content was measured via a hydroxyproline assay, and sulfated glycosaminoglycan content was measured via a 1,9-dimethylmethylene blue assay. Cellularity was determined via a double-stranded DNA assay. Immunohistochemical analysis for collagens I and II was also performed. Results-In vitro collagen synthesis was enhanced by growth factor stimulation. Although osteoarthritic-joint synoviocytes could undergo a fibrocartilage-like phenotypic shift, their production of collagenous extracellular matrix was less than that of normal-joint synoviocytes. Gene expressions of SOX-9 and RGS-10 were highest in the osteoarthritic-joint cells; Frzb expression was highest in growth factor treated cells. Conclusions and Clinical Relevance-Autogenous synovium may be a viable cell source for meniscal tissue engineering. Gene expressions of SOX-9 and RGS-10 may be potential future targets for in vitro enhancement of chondrogenesis. PMID: 21453151 [PubMed - in process] | | | | | | | | | |  | |  | |  |
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