Item Details

abstract

The extracellular matrix is a complex environment of mechanical and chemical cues vital to individual cell growth, tissue formation, and ultimately complete organ function. The field of regenerative medicine aims to recreate the unique biological properties found in specific tissue types and to incorporate these properties into substrates that support long term cell function for applications including tissue engineering, cell therapies, and disease models. Because of the complexity of the extracellular matrix, difficulties exist in characterizing and utilizing components of the matrix that contribute to the long term function and viability of cells. Primary liver epithelial cells, or hepatocytes, are easily isolated in large quantities. However, these cells quickly lose viability and function once removed from the native organ. In order to support hepatocyte phenotype in culture, decellularized liver matrix was incorporated into transplantable hyaluronic acid hydrogels. These substrates were shown to bind growth factors, support hepatocyte attachment, and promote cell junction formation. In liver tissue, the physical property of matrix stiffness affects a myriad of cell behaviors including; cell attachment, viability, function, growth factor utilization, motility, and cytoskeletal organization. Gels were crosslinked at different stiffnesses in order to mimic and test a variety of mechanical environments. The hepatocyte substrates were formulated within a narrow physiologic range from slightly above to slightly below that of native liver. Primary human hepatocyte attachment, viability, and functional output increased with stiffness. Stiffness influenced hepatocyte morphology, cell signaling, and expression of important liver specific markers dependent on duration in culture and presence or absence of matrix in the gel. In conclusion, data demonstrates that inclusion of extracellular matrix in primary hepatocyte cell culture substrates affects cell phenotype, and these effects are influenced by small changes in stiffness of the substrates. This thesis work suggests that substrate formulation and stiffness can be optimized for liver cell culture and different regenerative medicine applications.

subject

Decellularization

Hepatocytes

Hyaluronic acid

Hydrogels

Liver extracellular matrix

Stiffness

contributor

Deegan, Daniel (author)

Shupe, Thomas D (committee chair)

Opara, Emmanuel C (committee member)

Almeida-Porada, Graça D (committee member)

Seeds, Michael C (committee member)

Soker, Shay (committee member)

date

2016-01-11T09:35:25Z (accessioned)

2016-01-11T09:35:25Z (available)

2015 (issued)

degree

Molecular Medicine and Translational Science (discipline)

identifier

http://hdl.handle.net/10339/57438 (uri)

language

en (iso)

publisher

Wake Forest University

title

Effects of Liver Extracellular Matrix Gel Stiffness on Primary Hepatocyte Function

type

Dissertation