Date of Award

12-2001

Level of Access

Open-Access Thesis

Degree Name

Master of Science (MS)

Department

Civil Engineering

Advisor

Amyl Ghanem

Second Committee Member

Douglas W. Bousfield

Third Committee Member

Rebecca J. Van Beneden

Abstract

Chitosan (β-(l,4)-2-amino-2-deoxy-D-glucose) is a naturally occurring, abundant biopolymer exhibiting desirable biomaterial properties of biodegradability, low toxicity and good biocompatibility. These properties indicate the suitability of chitosan as a surface for mammalian cell growth. The goal of this thesis is to explore the potential for using chitosan as a surface for NIH 3T3 fibroblast attachment and growth. '4 standard, reproducible film-formation technique, based on other researchers techniques was established. The reproducibility of this technique. through characterization of the physical and chemical properties of these films, was good. The attachment and growth of NIH 3T3 fibroblasts on chitosan films and controls was measured. These films were modified by physical and chemical means to optimize the attachment and growth of the NIH 3T3 fibroblasts. Physical properties, including film tensile properties, surface roughness of films, and chemical properties including the degree of deacetylation (measure of number of acetylated amino groups in the chitosan polysaccharide) and surface free energy (SFE) estimated by contact angle measurements were performed to characterize the chitosan films. Chitosan films of 0.5, 1.5 and 3.0% (wlv) support the attachment and proliferation of NIH 3T3 fibroblasts at rates lower than polystyrene controls. The film tensile properties, surface roughness and surface free energies indicate that the film-formation technique gives films with reproducible physical and chemical properties. The sterilization of films with ultraviolet aAd infrared lamps (UV-IR) over time changes the water-in-air contact angle (WIA) and increases the overall SFE of the films. This is an important result because the WIA contact angle has been shown influential to the rate of cell attachment, and the SFE has been shown to affect the degree of fibroblast spreading. Our results indicate that UV-IR treatment of chitosan films can change the WIA contact angle and SFE of the films, and can potentially be used to optimize the attachment and spreading of fibroblasts on these films. The ability of these chitosan films to support cell attachment and growth indicates their potential use as biomedical surfaces. Good attachment and growth results in rapid and efficient wound repair. This research may result in the development of biodegradable tissue-engineering matrices. This development requires an understanding of the basic cell-chitosan surface interactions.

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