Research in Engineering and Aviation

Development of Poly(ethylene Glycol)-Collagen 3D Scaffolds

October 2011

Author(s): Taylor, R., Zustiak, S.P., Nossal, R., Sackett, D.

14th Annual Undergraduate Research Symposium in the Chemical and Biological Sciences at UMBC, Baltimore, MD, October 2011.

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National Institute of Health (NIH) Summer Research Program Poster Day, Bethesda, MD, August 2011.

Abstract

Our overall goal is to create 3 dimensional (3D) scaffolds with tunable physical and mechanical properties for future cell experiments involving drug screening, cell-matrix interactions, and drug delivery.  3D scaffolds more closely resemble in vivo conditions than the traditional 2 dimensional (2D) scaffolds and thus can serve as a bridge between 2D cultures and in vivo animal models.  The tunability of the developed scaffolds would also allow us to examine how scaffold physical properties impact cell growth and development.  In this project, we synthesized an acrylate-PEG-collagen copolymer that has the ability to covalently cross-link under UV irradiation to form 3D hydrogel scaffolds. The hydrogel incorporates PEG because it is biocompatible, structurally similar to the extracellular matrix, and approved for use in biological systems by the FDA. The PEG alone is responsible for the hydrogel mechanical properties but it is inert and does not support cell attachment. Collagen is responsible for the biological properties by providing adhesion sites to support cell attachment, growth and proliferation as well as scaffold degradability when in contact with proteases secreted by the cells. Currently, we are characterizing the swelling ratio and degradability of the developed scaffold and how different concentrations of PEGDA cross-linker and PEG-Collagen copolymer affect these properties.  The swelling ratio is an important measure of the gel’s pore size and hydrophilicity. We observed an inverse relationship between swelling ratio and polymer concentration.  Degradation time will allow us to determine a PEGDA concentration threshold past which the gel will not be degradable by proteases.