(188af) Remote Controlled Drug Delivery Using Nanocomposite Sol-Gel Materials

Remote controlled degradation and drug release have previously been demonstrated using magnetic nanoparticles incorporated into a biodegradable polymer matrix, where remote heating modulated the rate of degradation. The ability to remotely heat magnetic nanoparticles can also be used to cause other temperature-based transitions, such as the solution to gel to solution behavior (sol-gel) exhibited by some block copolymers in solution with an increase in temperature. In this work, we aim to use the heating of magnetic nanoparticles in an alternating magnetic field (AMF) to control the phase behavior of a sol-gel block copolymer system, and subsequently the release of a drug from the polymer depot. Pluronic F127, a poly(ethylene oxide) ? poly(propylene oxide) triblock copolymer system was used as the matrix material into which iron oxide magnetic nanoparticles, and a model drug was loaded. Polymer preparation was done using the cold method to dissolve the polymers in PBS buffer; nanoparticles were loaded using a sonication probe. Test tube inversion was used to determine the exact phase transition temperatures of both the pure and particles loaded systems. The magnitude of remote heating obtained by the incorporation of the iron oxide particles was analyzed using an IR camera. Drug release studies were completed using an aqueous solution as a sink as well as with a swollen PEG gel to mimic the properties of tissue in the body. Application of the AMF showed an enhancement of both drug and nanoparticle release from the sol-gel system.