Browsing by Subject "Mesenchymal stroma cell"

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Open Access
Glycosaminoglycan-Mimetic Signals Direct the Osteo/Chondrogenic Differentiation of Mesenchymal Stem Cells in a Three-Dimensional Peptide Nanofiber Extracellular Matrix Mimetic Environment
(American Chemical Society, 2016-02) Arslan, E.; Güler, Mustafa O.; Tekinay, A. B.
Recent efforts in bioactive scaffold development focus strongly on the elucidation of complex cellular responses through the use of synthetic systems. Designing synthetic extracellular matrix (ECM) materials must be based on understanding of cellular behaviors upon interaction with natural and artificial scaffolds. Hence, due to their ability to mimic both the biochemical and mechanical properties of the native tissue environment, supramolecular assemblies of bioactive peptide nanostructures are especially promising for development of bioactive ECM-mimetic scaffolds. In this study, we used glycosaminoglycan (GAG) mimetic peptide nanofiber gel as a three-dimensional (3D) platform to investigate how cell lineage commitment is altered by external factors. We observed that amount of fetal bovine serum (FBS) presented in the cell media had synergistic effects on the ability of GAG-mimetic nanofiber gel to mediate the differentiation of mesenchymal stem cells into osteogenic and chondrogenic lineages. In particular, lower FBS concentration in the culture medium was observed to enhance osteogenic differentiation while higher amount FBS promotes chondrogenic differentiation in tandem with the effects of the GAG-mimetic 3D peptide nanofiber network, even in the absence of externally administered growth factors. We therefore demonstrate that mesenchymal stem cell differentiation can be specifically controlled by the combined influence of growth medium components and a 3D peptide nanofiber environment.
Open Access
Spatial organization of functional groups on bioactive supramolecular glycopeptide nanofibers for differentiation of mesenchymal stem cells (MSCs) to brown adipogenesis
(American Chemical Society, 2016-12) Caliskan, O. S.; Sardan, Ekiz M.; Tekinay, A. B.; Güler, Mustafa O.
Spatial organization of bioactive moieties in biological materials has significant impact on the function and efficiency of these systems. Here, we demonstrate the effect of spatial organization of functional groups including carboxylate, amine, and glucose functionalities by using self-assembled peptide amphiphile (PA) nanofibers as a bioactive scaffold. We show that presentation of bioactive groups on glycopeptide nanofibers affects mesenchymal stem cells (MSCs) in a distinct manner by means of adhesion, proliferation, and differentiation. Strikingly, when the glutamic acid is present in the glycopeptide backbone, the PA nanofibers specifically induced differentiation of MSCs into brown adipocytes in the absence of any differentiation medium as shown by lipid droplet accumulation and adipogenic gene marker expression analyses. This effect was not evident in the other glycopeptide nanofibers, which displayed the same functional groups but with different spatial organization. Brown adipocytes are attractive targets for obesity treatment and are found in trace amounts in adults, which also makes this specific glycopeptide nanofiber system an attractive tool to study molecular pathways of brown adipocyte formation.