Fabrication and Characterization of Biodegradable, Thermal-Responsive Silk Composite Membrane

In this work, we present a study on a thermal-responsive biodegradable membrane composed of silk fibroin and iron oxide nanoparticles as potential candidate material for implantable smart drug delivery microsystems. Ethanol annealing increased the content of beta-sheet structures of biodegradable silk fibroin in the membrane enabling extended water stability for several days as a potential transient implantable. In particular, we show that the thermal-responsiveness of the silk fibroin film has consistently the same thermal degradation temperature of 250 degrees C, independent of the ethanol annealing. We also provide data of how the composite heating rate correlates with the amount of magnetic nanoparticles and magnetic field parameters such as frequency and flux density. The maximum heating rate achieved in our experiments was similar to 20 degrees C/min for magnetic field of 111.1 kHz and 25.3 mT. The silk composite was further shaped by solution casting into 15 mu m-thick membranes with 15 nm magnetic nanoparticles uniformly distributed and studied as a model system for tunable drug release microsystems.