Control of covalent and non-covalent presentation of biomolecules within collagen GAG scaffolds

Mass transport continues to be a major bottleneck in the development of biomaterials. The diffusive limitation of biomaterials restricts cell viability to regions where nutrients are readily available. To overcome this transport limitation, angiogenic biomaterials that utilize biomolecular cues such as Vascular Endothelial Growth Factor to drive vascularization are being explored. To develop these biomaterials, techniques to present these factors must first be investigated. Experiments were conducted with collagen glycosaminoglycan (CG) scaffolds to determine optimal conditions to control the levels of covalent and non-specific attachment of biotinylated Concanavalin A (ConA) via two distinct covalent patterning techniques: 1-ethyl-3-3-dimethylaminopropylcarbodiimide hydrochloride (EDC) crosslinking and benzophenone (BP) biophotolithography. The results indicated that longer contact time of ConA with the CG scaffold independent of covalent attachment methods led to significantly higher amounts of fouling (non-specific attachment). The fouling was best minimized using a 1 hour wash followed by an overnight wash in a solution of 5% sucrose in PBS compared to no wash, PBS, 5% BSA in PBS, and 1% Tween in PBS. The total ConA immobilized by EDC chemistry was found to be strongly correlated to the amount of protein loading and was higher for an EDC:N-hydroxysuccinimide:Carboxyl ratio of 5:12.5:1 compared to 2.5:6.25:1 and 10:25:1. For BP chemistry, the UV exposure time was found to be significantly correlated to the total amount of ConA immobilized. Components of the scaffolds were also tested to determine their impact on covalent patterning and fouling. It was found that the Collagen Matrix yielded BP patterns with better resolution and less background noise caused by non-specific attachment. The use of Chondroitin Sulfate was found to have significantly less fouling than Hyaluronic Acid within scaffolds, which was unexpected. Further, the Hyaluronic Acid yielded significantly higher total ConA immobilization.

Name thesis:degree_name

M.S.

Level thesis:degree_level

Thesis

Discipline thesis:degree_discipline

Chemical Engineering

Grantor

University of Illinois at Urbana-Champaign

Year dc:date

2013

Author dc:creator

• Pence, Jacquelyn

Contributors dc:contributor

• Harley, Brendan A.

• Collagen- Glycosaminoglycan (Collagen-GAG)
• Scaffolds
• Benzophenone
• Photolithography
• 1-ethyl-3- 3-dimethylaminopropylcarbodiimide hydrochloride (EDC)
• Carbodiimide

Statement dc:rights

• Copyright 2012 Jacquelyn C. Pence

Language dc:language

en

Handle dc:identifier

http://hdl.handle.net/2142/42307

OAI identifier oai:identifier

oai:www.ideals.illinois.edu:2142/42307