Effects of Temperature on the Mechanical Properties of PEGDA and PDMS Copolymer Scaffold for Tissue Engineering

Tissue engineering is a growing field of materials research concerned with finding new materials and methods for the replacement or improvement of natural tissue structures. Previous studies have shown poly (ethylene glycol) diacrylate (PEGDA) to be a promising engineering tissue structure, or scaffold material. However, PEGDA scaffolds have been shown to lack sufficient mechanical properties that would be required for implantation in the human body. More research must be done to tune the mechanical properties of the scaffold. Many research institutions do not have access to all testing equipment needed to fully study the limitations of scaffold samples. Thus, the need for collaboration between institutions is often necessary. Numerous common testing methods require consistent environmental conditions to maintain the structure of scaffold to accurately collect data. The study of the limitations of environmental conditions is significant to avoid degradation of the structure and therefore keep the mechanical properties of scaffold samples. Experiements have shown PEGDA scaffolds to experience a decrease in strength and elasticity after refrigeration for 24 and 48 hours, but a restoration of mechanical properties was found after 72 hours. No studies have looked at mechanical properties beyond 72 hours of refrigeration. This study investigates the effects of temperature on the mechanical properties of UV cross-linked PEGDA and polydimethylsiloxane (PDMS) copolymer scaffolds. Utilizing Fourier Transmission Infrared Spectroscopy, Scanning Electron Microscopy, X-ray Diffraction, and Raman Spectroscopy, the characterization of the copolymer scaffolds was performed. Compression testing was then performed on a QT 50 Universal Testing Machine at a rate of .75<i> mm</i>/<i>min</i>. These results were compared with that of refrigerated copolymer samples and plain PEGDA scaffold samples. Samples were refrigerated at 0 degrees Centigrade for 24, 48, 72, and 96 hours.