2026-09-19T15:04:56Zhttps://dspace.mit.edu/server/oai/requestoai:dspace.mit.edu:1721.1/89992022-01-13T07:54:18Zcom_1721.1_7582com_1721.1_7581col_1721.1_131022
Robert Langer.
Carrier, Rebecca Lyn, 1973-
Massachusetts Institute of Technology. Department of Chemical Engineering
2005-09-27T19:48:42Z
2005-09-27T19:48:42Z
1999
2000
http://hdl.handle.net/1721.1/8999
47359386
Thesis (Sc.D.)--Massachusetts Institute of Technology, Dept. of Chemical Engineering, 2000.
Includes bibliographical references.
Tissue engineering may be useful in fighting heart disease since it offers the possibility of creating functional tissue equivalents for scientific studies and tissue repair. In the present work, we examined how variations in cultivation parameters of a model tissue engineering system influenced cardiac tissue morphogenesis. The central hypothesis was that using a tissue engineering system consisting of isolated cardiac cells, polymer scaffolds, and tissue culture bioreactors, we could engineer cardiac muscle mimicking native tissue in structure and function in the presence of appropriate biochemical and physical signals. The specific objectives were to: ( 1) vary key parameters of the model tissue engineering system, and (2) structurally and functionally characterize engineered cardiac muscle so that effects of parameter variations could be assessed and engineered tissue could be compared to native tissue. Effects of key cultivation parameters, including (I) cell source, (2) cell seeding density, (3) cell seeding vessel, and (4) tissue culture bioreactor on structure and function of engineered cardiac cell-polymer constructs were studied. Advantages of seeding mammalian cells at high densities (6-Sx 106 cells/Smm diameter x 2mm thick scaffold) under mixed conditions and culturing constructs in rotating laminar flow bioreactors were demonstrated, but constructs had interiors (> IOOμm tissue depth) consisting of mostly empty space due to diffusional mass transport limitations. We attempted to overcome diffusional limitations by directly perfusing culture medium through the constructs. Perfusion significantly improved the uniformity of the cell distribution and enhanced expression of a differentiated cell phenotype in comparison to non-perfused (i.e. flask) cultures. Control of the cell microenvironment in the perfusion system was also used to study relationships between oxygen tension and properties of cardiac constructs. Oxygen tension was directly correlated with DNA and protein contents (r=0.88 and 0.89, respectively), aerobic metabolism (r=0.97), muscle protein expression, and ultrastructural differentiation. Characterization of cardiac construct structure, composition, cell phenotype, and in vitro function demonstrated cardiac specific protein expression, metabolic activity similar to that of native tissue, and differentiated ultrastructural features (e.g. sarcomeres). The results support the utility of engineered cardiac muscle as a native tissue model for in vitro studies and eventually for in vivo tissue repair.
by Rebecca Lyn Carrier.
Sc.D.
124 leaves
10804022 bytes
10803782 bytes
application/pdf
application/pdf
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
Chemical Engineering
Cardiac tissue engineering : bioreactor cultivation parameters
Thesis
application/pdf
false
Publication
unknown
unknown
<Publication xmlns="https://www.openaire.eu/cerif-profile/1.1/" id="f864bbd5-5787-41c2-b25e-7f605ae399c0">
<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>Cardiac tissue engineering : bioreactor cultivation parameters</Title>
<PublishedIn>
<Publication>
</Publication>
</PublishedIn>
<PublicationDate>2000</PublicationDate>
<Authors>
<Author>
<DisplayName>Carrier, Rebecca Lyn, 1973-</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>Chemical Engineering</Keyword>
<Abstract>Tissue engineering may be useful in fighting heart disease since it offers the possibility of creating functional tissue equivalents for scientific studies and tissue repair. In the present work, we examined how variations in cultivation parameters of a model tissue engineering system influenced cardiac tissue morphogenesis. The central hypothesis was that using a tissue engineering system consisting of isolated cardiac cells, polymer scaffolds, and tissue culture bioreactors, we could engineer cardiac muscle mimicking native tissue in structure and function in the presence of appropriate biochemical and physical signals. The specific objectives were to: ( 1) vary key parameters of the model tissue engineering system, and (2) structurally and functionally characterize engineered cardiac muscle so that effects of parameter variations could be assessed and engineered tissue could be compared to native tissue. Effects of key cultivation parameters, including (I) cell source, (2) cell seeding density, (3) cell seeding vessel, and (4) tissue culture bioreactor on structure and function of engineered cardiac cell-polymer constructs were studied. Advantages of seeding mammalian cells at high densities (6-Sx 106 cells/Smm diameter x 2mm thick scaffold) under mixed conditions and culturing constructs in rotating laminar flow bioreactors were demonstrated, but constructs had interiors (> IOOμm tissue depth) consisting of mostly empty space due to diffusional mass transport limitations. We attempted to overcome diffusional limitations by directly perfusing culture medium through the constructs. Perfusion significantly improved the uniformity of the cell distribution and enhanced expression of a differentiated cell phenotype in comparison to non-perfused (i.e. flask) cultures. Control of the cell microenvironment in the perfusion system was also used to study relationships between oxygen tension and properties of cardiac constructs. Oxygen tension was directly correlated with DNA and protein contents (r=0.88 and 0.89, respectively), aerobic metabolism (r=0.97), muscle protein expression, and ultrastructural differentiation. Characterization of cardiac construct structure, composition, cell phenotype, and in vitro function demonstrated cardiac specific protein expression, metabolic activity similar to that of native tissue, and differentiated ultrastructural features (e.g. sarcomeres). The results support the utility of engineered cardiac muscle as a native tissue model for in vitro studies and eventually for in vivo tissue repair.</Abstract>
<Access xmlns="http://purl.org/coar/access_right"
>
</Access>
</Publication>