Iron/ethylcellulose (core/shell) nanoplatform loaded with 5-fluorouracil for cancer targeting.

Even though 5-fluorouracil has been demonstrated to display antitumor activity against a wide variety of cancers, high doses are needed to bring out the required therapeutic activity that could simultaneously lead to severe side effects. We hypothesized that the efficient delivery of 5-fluorouracil to tumors using a magnetic nanoplatform could reduce the dose required to obtain sufficient anticancer response. Thus, we have formulated a 5-fluorouracil-loaded magnetic nanomedicine consisting of a magnetic core (iron) and a biocompatible polymeric shell (ethylcellulose). These core/shell nanoparticles were synthesized by an emulsion solvent evaporation process, and 5-fluorouracil loading was assayed by surface incorporation onto the preformed nanocomposites, and by drug incorporation into the magnetic colloid. The contributions of both the surface and the polymeric network to the overall drug loading were investigated by means of optical absorbance and electrophoretic mobility determinations. 5-Fluorouracil entrapment into the polymeric matrix yielded a higher drug loading and a slower drug release profile as compared with drug adsorption. These preliminary results suggest the potential of this stimuli-sensitive drug carrier for cancer targeting. 2010 Elsevier B.V. All rights reserved.