Shelf Life Study of Electrospun PLGA Copolymers

Poly(lactic-co-glycolic acid) (PLGA) is one of the most commonly used copolymers for electrospinning in tissue engineering applications. However, most research has not focused on the copolymer itself in regards to how long it can be used effectively and if varying the concentrations of polylactic acid (PLA) and polyglycolic acid (PGA) affect the resulting properties. Electrospinning is the method we use to create the three-dimensional constructs, or “scaffolds”, for the blood vessel mimic (BVM) in the tissue engineering lab. The aim of our project was to investigate if the morphology and mechanical properties of the scaffolds changed over time when they were stored in a dessicator. In addition, the morphology and properties from 75:25 and 85:15 PLGA copolymers were studied to determine whether there were significant differences in fiber diameter, elastic modulus, or critical yield strength between them via Scanning Electron Microscopy (SEM) image analysis and tensile testing of the samples. These same three parameters were analyzed for the distal, medial, and proximal regions of the scaffold for each concentration of PLGA. The main significant finding was that the regions of the scaffold were relatively uniform in their properties. No timepoints were established, since there was such large variation in the data and the trends were inconsistent. A larger and longer duration study is needed to determine whether there is an ideal timeframe to use the scaffolds. Acknowledgements We would like to thank the following people for helping to contribute to our work: First and foremost, Dr. Kristen Cardinal for being a terrific and very supportive senior project advisor throughout the whole process. Thank you for letting us use the tissue engineering lab for our research and for making sure we had everything we needed to finish the project in a timely manner. You were paramount to our success; The Hannah Forbes Foundation, for funding some of our research. We would not have been able to complete our project without your gracious support; Aubrey Dyer, for providing the initial Visual Basic macro that we used for the tensile testing procedure; Dr. Lanny Griffin, for helping us modify the macro to suit our testing procedure; Dr. Lily Laiho, for granting us permission to use the SEM for our research; Mr. Laiho, for ordering any extra materials or supplies we needed; Deven Patel and Shane Tipton, for teaching us the masterful ways of electrospinning; All of the tissue engineering lab folks, including Stephan, Corey, Jakub, Alex, Scott, Mike, Rachel, and Sarah, for all your moral support , constructive criticism, and comradery; And finally, we would like to thank our parents and close relatives for all their love and support. We would certainly not have gotten this far without you all. Table of