479719 Polymer Nanoparticle/Hydrogel Composites to Extend Drug Delivery

Monday, November 14, 2016
Grand Ballroom B (Hilton San Francisco Union Square)
Joyce Obeng and Jae Young Lee, Department of Chemical Engineering, Bucknell University, Lewisburg, PA

Extending small molecule controlled drug delivery from hydrogels beyond a few days is a major challenge. We have been developing an injectable hydrogel formulation with embedded polymer nanoparticles, filled with a small molecule model drug, to provide controlled release for greater than 10 d. Polymer nanoparticles (PLGA) loaded with between 8 and 20 wt % rhodamine 6G were prepared using an impingement jets mixer to facilitate solvent displacement and formation of nanoparticles. Excess solvent was removed and the particles were freeze dried. We used an ultrafiltration cell to remove excess surfactant from the nanoparticles before using them in the hydrogel formulation. The concentrated solution was used to make Poly(ethylene glycol) diacrylate (PEGDA-575) and ethoxylated trimethylolpropane tri-3-mercaptopropionate (ETTMP) hydrogel precursor solutions. When the hydrogel precursors are mixed and put in the oven at 37 °C, they crosslink and form a solid hydrogel. In this work, we studied and optimized the parameters that affect the curing of the hydrogel. We developed an efficient method of curing our hydrogels with embedded nanoparticles in under 3 min. We also improved the rate of Ultrafiltration of our sample that reduced the filtration time from several days to 5 h. Finally, we qualitatively observed that it took 12 d for the dye to fully release from the hydrogel/polymer nanoparticle composite.

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