title: Regulation of stem cell differentiation by control of retinoic acid gradients in hydrospun 3D scaffold.
abstract: Morphogen gradients have been associated with differential gene expression and are implicated in the triggering and regulation of developmental biological processes. This study focused on creating morphogenic gradients through the thickness of hydrospun scaffolds. Specifically, electrospun poly(ε-caprolactone) fibers were loaded with all-trans-retinoic acid (ATRA), and designed to release ATRA at a predetermined rate. Multilayered scaffolds designed to present varied initial ATRA concentrations were then exposed to flow conditions in a bioreactor. Gradient formation was verified by a simple convection-diffusion mathematical model approving establishment of a continuous solute gradient across the scaffold. The biological value of the designed gradients in scaffolds was evaluated by monitoring the fate of murine embryonal carcinoma cells embedded within the scaffolds. Cell differentiation within the different layers matched the predictions set forth by the theoretical model, in accordance with the ATRA gradient formed across the scaffold. This tool bears powerful potential in establishing in vitro simulation models for better understanding the inner workings of the embryo.
authors.affiliation: Russell Berrie Nanotechnology Institute, Technion, Haifa 32000, Israel.
authors.forename: Roey
authors.initials: R
authors.lastname: Tzezana
authors.forename: Stanislav
authors.initials: S
authors.lastname: Reznik
authors.forename: Jacob
authors.initials: J
authors.lastname: Blumenthal
authors.forename: Eyal
authors.initials: E
authors.lastname: Zussman
authors.forename: Shulamit
authors.initials: S
authors.lastname: Levenberg
mesh_terms: D000818:Animals; D015415:Biomarkers / Q000378:metabolism; D019149:Bioreactors; D015820:Cadherins / Q000235:genetics / Q000378:metabolism; D002454:Cell Differentiation / Q000187:drug effects; D049109:Cell Proliferation / Q000187:drug effects; D055664:Electrochemical Techniques; D004622:Embryo, Mammalian; D054278:Embryonal Carcinoma Stem Cells / Q000166:cytology / Q000187:drug effects* / Q000378:metabolism; D047108:Embryonic Development; D018507:Gene Expression Regulation, Developmental / Q000187:drug effects; D051379:Mice; D008954:Models, Biological; D009474:Neurons / Q000166:cytology / Q000187:drug effects* / Q000378:metabolism; D011091:Polyesters / Q000737:chemistry / Q000494:pharmacology*; D013234:Stem Cells / Q000166:cytology / Q000187:drug effects* / Q000378:metabolism; D054457:Tissue Scaffolds; D014212:Tretinoin / Q000737:chemistry / Q000494:pharmacology*
chemical_list: D015415:Biomarkers; D015820:Cadherins; C489083:Cdh2 protein, mouse; D011091:Polyesters; C016240:polycaprolactone; D014212:Tretinoin