- 2:20 PM

Nanocomposite Biodegradable Hydrogels: Preparation and the Analysis of Heating, Degradation, and Drug Release

Ashley M. Hawkins, Chemical and Materials Engineering, University of Kentucky, Lexington, KY 40506 and J. Zach Hilt, Chemical & Materials Engineering, University of Kentucky, 177 F. Paul Anderson Tower, Lexington, KY 40506.

Biodegradable polymers are extremely versatile materials that can be used in many applications, but current materials exhibit degradation profiles that are pre-programmed. Thus, there is limited or no ability to modulate the degradation once it is applied (e.g., implant, subcutaneous injection, etc.). This research involves the incorporation of nanoscale heat sources into a biodegradable polymer system. It is hypothesized that the heating from the particles can affect the degradation rate and therefore the drug release from the film. For this hypothesis to hold, several requirements must be met. First, the heating obtained from the nanoparticles must be significant. Secondly, the polymer system must have temperature dependent degradation. Finally, the drug must be released through a degradation process as opposed to dissolution.

Nanocomposite biodegradable polymers have been designed and developed that exhibit degradation profiles that can be remotely controlled by an alternating magnetic field. In particular, biodegradable hydrogels have been prepared from macromers synthesized through a condensation reaction between a diacrylate and amine. The incorporation of magnetic nanoparticles allows heating of the films, which can therefore affect many of the other properties of the polymer (e.g., degradation rate). Thus, the drug release can be controlled by altering the degradation rate through remote heating of the nanoparticles. Degradable hydrogels with and without iron oxide nanoparticles (and drugs) were successfully prepared. Characterization of the gels was done through viscometer readings, FTIR, and gel permeation chromatography methods. Heating studies were done using an infrared camera and induction heating instrument and the gels were shown to have temperature dependent degradation based on gravimetric analysis methods. Remote control drug release was also demonstrated by subjecting the drug-loaded gels to magnetic field exposure.