Title page for ETD etd-09062012-143649


Type of Document Dissertation
Author Larkin, Adam Lyston
URN etd-09062012-143649
Title The Design of Three-Dimensional Multicellular Liver Models Using Detachable, Nanoscale Polyelectrolyte Multilayers
Degree PhD
Department Chemical Engineering
Advisory Committee
Advisor Name Title
Rajagopalan, Padmavathy Committee Chair
Davis, Richey M. Committee Co-Chair
Lee, Yong Woo Committee Member
Marand, Eva Committee Member
Keywords
  • free-standing
  • multicellular
  • liver mimic
  • polyelectrolyte multilayers
Date of Defense 2012-08-29
Availability unrestricted
Abstract
We report the design and assembly of three-dimensional (3D) multi-cellular liver models comprised of primary rat hepatocytes, liver sinusoidal endothelial cells (LSECs), and Kupffer cells (KCs). LSECs and KCs in the liver model were separated from hepatocytes by a nanoscale, detachable, optically transparent chitosan and hyaluronic acid (HA) polyelectrolyte multilayer (PEM) film. The properties of the PEM were tuned to mimic the Space of Disse found in liver. The thickness of the detachable PEM was 650 to 1000 nm under hydrated conditions. The Young’s modulus of the PEM was approximately 42 kPa, well within the range of modulus values reported for bulk liver. The 3D liver models comprised of all three cell types and a detachable PEM exhibited stable urea production and increased albumin secretion over a 12 day culture period. Additionally, the 3D liver model maintained the phenotype of both LSECs and KCs over the 12 day culture period, verified by CD32b and CD163 staining, respectively. Additionally, CYP1A1 enzyme activity increased significantly in the 3D liver models. The number of hepatocytes in the 3D liver model increased by approximately 60% on day 16 of culture compared to day 4 indicating. Furthermore, only the 3D hepatic model maintained cellular compositions virtually identical to those found in vivo. DNA microarray measurements were conducted on the hepatocyte fractions of the 3D liver mimic to obtain insights into hepatic processes. Gene sets up-regulated in the 3D liver model were related to proliferation, migration, and deposition of extracellular matrix, all functions observed in regenerating hepatocytes. Taken together, these results suggest that inter-cellular signaling between the different cell types in the 3D liver model led to increased hepatic functions. To the best of our knowledge, this is the first study where three of the major hepatic cell types have been incorporated into a model that closely mimics the structure of the sinusoid. These studies demonstrate that the multi-cellular liver models are physiologically relevant. Such models are very promising to conduct detailed investigations into hepatic inter-cellular signaling.
Files
  Filename       Size       Approximate Download Time (Hours:Minutes:Seconds) 
 
 28.8 Modem   56K Modem   ISDN (64 Kb)   ISDN (128 Kb)   Higher-speed Access 
  Larkin_AL_D_2012.pdf 11.90 Mb 00:55:04 00:28:19 00:24:46 00:12:23 00:01:03
  Larkin_AL_D_2012_Copyright.pdf 352.47 Kb 00:01:37 00:00:50 00:00:44 00:00:22 00:00:01

Browse All Available ETDs by ( Author | Department )

dla home
etds imagebase journals news ereserve special collections
virgnia tech home contact dla university libraries

If you have questions or technical problems, please Contact DLA.