Electronic Theses and Dissertations

Identifier

180

Date

2010

Document Type

Thesis

Degree Name

Master of Science

Major

Biomedical Engineering

Committee Chair

Joel Bumgardner

Committee Member

Judith Cole

Committee Member

Warren Haggard

Committee Member

John Williams

Abstract

Stromals cells, W-20-17, were subjected to daily 30 minute doses of 800microstrain at 1Hz for six consecutive days on a commercially pure titanium substrate with a custom 4-point-bend cell strain system to simulate the bone-implant interface in vivo. The loading schemes include continuous and intermittent (15minutes of strain, 15 minutes of rest, 15 minutes of strain) dosing in both compresssive and tensile strain. Cell lysates and media were collected after 12hrs on the plate and after 1, 3, and 6 days of straining. DNA, total protein, and ALP concentrations were assayed to assess the results of the different strains. Overall the strained cells proliferated similiarly to the unstrained control but produced increased concentrations of ALP, when compared to the unstrained control, suggersting that the cells are undergoing differentiation. Compressive strains had little effect on cell proliferation and only a small impact on ALP activity. Interestingly, tensile strains resulted in the largest normalized ALP activities, 68% increased response to continuous tension over unstrained control, with the leaste amount of proliferation. These data suggest that the relationship between tensile and compressive responses may be complicated and depend on the other straining parameters. Also the W-20-17 cells under the strain conditions of this study chose to differentiate rather than proliferate in response to the tensile strain following the tendency for bones to remodel to minimize tensile strains. Intermittently straining the cells did not appear to cause an increased response when compared to continuous strain.

Comments

Data is provided by the student.

Library Comment

Dissertation or thesis originally submitted to the local University of Memphis Electronic Theses & dissertation (ETD) Repository.

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