Articular cartilage repair

Enhancing adipose stem cell chondrogenesis: A study on the roles of dexamethasone, transforming growth factor β3 and ascorbate supplements and their combination

Published on: 31st July, 2017

OCLC Number/Unique Identifier: 7317597470

Varied exogenous chondrogenic factors (CFs) are implicated in promoting differentiation of stem cells along a chondrocyte lineage in the field of regenerative tissue engineering for articular cartilage repair. The effects of dexamethasone, transforming growth factor β3 (TGF-β3), ascorbate, and their combinations, on mRNA expression in micromass-cultured human adipose derived stem cells (hADSCs) were investigated as a function of time. Indices include chondrogenic, hypertrophic, angiogenic, fibrogenic and osteogenic markers along with mechanical properties, assessed by atomic force microscopy. Early in the culture, i.e., at day three, no significant differences in mRNA expression of SOX9, aggrecan, lubricin, Col XI, Col X, vascular endothelial growth factor, Col I, and alkaline phosphatase were observed among samples treated with different CFs. However, significant differences in mRNA expression levels of pre-mentioned markers among samples treated with each CF exist when samples were supplied with the CFs for more than three days. A new indexing scheme summing expression of chondrogenic and subtracting non-chondrogenic angiogenic, fibrogenic and osteogenic marker levels shows dexamethasone is the overall leading CF among the factors and their combinations. Based on this scheme, we have projected not only the possible signaling pathways which might be affected by addition of CFs but also hypothetical indexes that may occur upon temporal variation of growth factor regimens.
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A flow perfusion bioreactor with controlled mechanical stimulation: Application in cartilage tissue engineering and beyond

Published on: 13th June, 2018

OCLC Number/Unique Identifier: 7815003397

To repair articular cartilage (AC) defects in osteoarthritic patients, one approach is to engineer three-dimensional grafts with physicochemical properties similar to endogenous AC. Such grafts can be grown in bioreactors that provide environmental conditions favoring chondrogenesis. Studies show mechanical stimulation during the culturing process greatly enhances development of functional engineered grafts. A review of literature on bioreactor options reveals a lack of capacity to simultaneously stimulate cells with a combination of shear stress and oscillating hydrostatic pressure, both of which are important parts of the in vivo AC environment. It is hypothesized that combining both forces in a new bioreactor design will contribute to better AC tissue growth. In this paper, we provide a brief review of bioreactors and describe a new computer-controlled perfusion and pressurized bioreactor system, and the novelty of its control programming features for service in a host of applications. We briefly summarize results on synergistic effects in employing perfusion, oscillating hydrostatic pressure in a scaffold free environment and with the addition of encapsulation for inducing chondrogenesis. We further describe efforts to modify the newly developed system to include a continuous flow and pressurized centrifugal mode to enhance further the capabilities for inclusion of very high shear stresses. Applications for several other cell and tissue engineering approaches are discussed. 
Cite this ArticleCrossMarkPublonsHarvard Library HOLLISGrowKudosResearchGateBase SearchOAI PMHAcademic MicrosoftScilitSemantic ScholarUniversite de ParisUW LibrariesSJSU King LibrarySJSU King LibraryNUS LibraryMcGillDET KGL BIBLiOTEKJCU DiscoveryUniversidad De LimaWorldCatVU on WorldCat