Electroactive Silk Fibroin Films for Electrochemically Enhanced Delivery of Drugs

Abstract

Biomaterials capable of controlling the delivery of drugs have the potential to treat a variety of conditions. Herein, the preparation of electrically conductive silk fibroin film-based drug delivery devices is described. Casting aqueous solutions of Bombyx mori silk fibroin, followed by drying and annealing to impart β-sheets to the silk fibroin, assure that the materials are stable for further processing in water; and the silk fibroin films are rendered conductive by generating an interpenetrating network of a copolymer of pyrrole and 3-amino-4-hydroxybenzenesulfonic acid in the silk fibroin matrix (characterized by a variety of techniques including circular dichroism, Fourier-transform infrared spectroscopy, nuclear magnetic resonance, Raman spectroscopy, resistance measurements, scanning electron microscopy-energy dispersive X-ray spectroscopy, thermogravimetric analysis, X-ray diffraction, and X-ray photoelectron spectroscopy). Fibroblasts adhere on the surface of the biomaterials (viability assessed using an (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide) assay and visualized using a confocal microscope), and a fluorescently labeled drug (Texas-Red Gentamicin) can be loaded electrochemically and released (µg cm−2 quantities) in response to the application of an electrical stimulus.