AVS 49th International Symposium
    Biomaterials Thursday Sessions
       Session BI-ThA

Paper BI-ThA9
The Adaptation of Hydrogel Scaffolds to Three Dimensional Tissue Construction of Cylindrical Vessels

Thursday, November 7, 2002, 4:40 pm, Room C-201

Session: Cell Patterning to Engineer Function
Presenter: E.A. Roth, Clemson University
Authors: E.A. Roth, Clemson University
A. Gutowska, Pacific Northwest National Laboratory
T. Boland, Clemson University
Correspondent: Click to Email
This study investigates the ability of hydrogels to establish patterns for cell growth and their application to the construction of three-dimensional tissues. A variety of hydrogels are being investigated for this application including a collagen based hydrogel and Poly-N-Isopropyl Acrylamide (polyNIPAAm) based copolymers, which undergo liquid-gel transformations in response to temperature changes. The end goal is to construct viable cylindrical vessels that maintain stability, after hydrogel absorption or removal has occurred. A high-throughput cell printing system is under development that allows for accurate cell placement in pre-designed patterns. In this system, bioabsorbable hydrogels and cellular solutions are precisely deposited by needles connected to piezo electric pumps programmed through a software interface. A second method employs a mold consisting of two concentric cylinders, which has been designed to create vessels consisting of smooth muscle cells propagated in a hydrogel matrix. The outer surface of the annulus acts as a structural component during hydrogel stabilization and cellular proliferation. To allow for mold removal, this surface is grafted with polyNIPAAm so that upon slight cooling, the tissue can detach with all cellular junctions intact due to a decrease in hydrophobicity of the polymer. The inner surface of the annulus, composed of an inert nanoporous material, allows for nutrient diffusion from a media reservoir contained in the center of the mold. After sufficient culture time the mold is removed leaving a freestanding cylindrical vessel. Results from both of these methods will be discussed.