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Myron Spector. Jennings, Edward B., III (Edward Bernard) Massachusetts Institute of Technology. Dept. of Mechanical Engineering. Massachusetts Institute of Technology. Department of Mechanical Engineering 2009-06-30T16:24:03Z 2009-06-30T16:24:03Z 2008 2008 http://hdl.handle.net/1721.1/45835 319602950 Thesis (S.B.)--Massachusetts Institute of Technology, Dept. of Mechanical Engineering, 2008. Includes bibliographical references (leaf 28). Healing by contraction is responsible for scarring in adults. Embryos heal by regeneration but the mechanism is unknown. Alpha-smooth muscle actin ([alpha]-SMA) is the protein responsible for contraction, thus determining if it is present in embryos which heal by regeneration will further our knowledge about the causes of regenerative healing. This thesis experimentally determined the presence of [alpha]-SMA in these cell types by the following procedure. Embryonic and mesenchymal stem cells of various species were cultured and seeded into collagen scaffolds. Contractile behavior was determined by measuring the diameter change of the scaffolds over time. Alpha-smooth muscle actin presence was determined by immunohistochemical evaluation. This study found that while all the cell types displayed alpha smooth muscle actin presence in monolayer, not every cell type contracted when seeded into the collagen scaffolds designed to mimic the in vivo environment. Specifically, the embryonic stem cells did not contract. Upon staining, the embryonic stem cell seeded scaffolds and several of the mesenchymal stem cell seeded scaffolds, which did contract, did not stain positive for [alpha]-SMA. These results imply that the embryonic scaffolds did not generate actin filament bundles, and that several of the mesenchymal stem cell seeded scaffolds were imaged after [alpha]-SMA expression in them ceased. by Edward B. Jennings, III. S.B. 33 leaves eng Massachusetts Institute of Technology M.I.T. theses are protected by copyright. They may be viewed from this source for any purpose, but reproduction or distribution in any format is prohibited without written permission. See provided URL for inquiries about permission. http://dspace.mit.edu/handle/1721.1/7582 Mechanical Engineering. Determining alpha-smooth muscle actin expression in embryonic and mesenchymal stem cells of assorted mammals seeded in collagen scaffolds in vitro Thesis application/pdf false Publication unknown unknown <Publication xmlns="https://www.openaire.eu/cerif-profile/1.1/" id="8b9aafbd-9ef4-48bd-b78a-4d630fc260c0"> <Type xmlns="https://www.openaire.eu/cerif-profile/vocab/COAR_Publication_Types">http://purl.org/coar/resource_type/c_1843</Type> <Language>eng</Language> <Title>Determining alpha-smooth muscle actin expression in embryonic and mesenchymal stem cells of assorted mammals seeded in collagen scaffolds in vitro</Title> <PublishedIn> <Publication> </Publication> </PublishedIn> <PublicationDate>2008</PublicationDate> <Authors> <Author> <DisplayName>Jennings, Edward B., III (Edward Bernard)</DisplayName> <Affiliation> <OrgUnit> </OrgUnit> </Affiliation> </Author> </Authors> <Editors> </Editors> <Publishers> <Publisher> <DisplayName>Massachusetts Institute of Technology</DisplayName> <OrgUnit /> </Publisher> </Publishers> <License>http://dspace.mit.edu/handle/1721.1/7582</License> <Keyword>Mechanical Engineering.</Keyword> <Abstract>Healing by contraction is responsible for scarring in adults. Embryos heal by regeneration but the mechanism is unknown. Alpha-smooth muscle actin ([alpha]-SMA) is the protein responsible for contraction, thus determining if it is present in embryos which heal by regeneration will further our knowledge about the causes of regenerative healing. This thesis experimentally determined the presence of [alpha]-SMA in these cell types by the following procedure. Embryonic and mesenchymal stem cells of various species were cultured and seeded into collagen scaffolds. Contractile behavior was determined by measuring the diameter change of the scaffolds over time. Alpha-smooth muscle actin presence was determined by immunohistochemical evaluation. This study found that while all the cell types displayed alpha smooth muscle actin presence in monolayer, not every cell type contracted when seeded into the collagen scaffolds designed to mimic the in vivo environment. Specifically, the embryonic stem cells did not contract. Upon staining, the embryonic stem cell seeded scaffolds and several of the mesenchymal stem cell seeded scaffolds, which did contract, did not stain positive for [alpha]-SMA. These results imply that the embryonic scaffolds did not generate actin filament bundles, and that several of the mesenchymal stem cell seeded scaffolds were imaged after [alpha]-SMA expression in them ceased.</Abstract> <Access xmlns="http://purl.org/coar/access_right" > </Access> </Publication>