Nano-ferrosponges for controlled drug release

Magnetic sponge-like hydrogels (ferrosponges) were fabricated by using an in-situ synthesis of magnetic nanoparticles (MNPs) in the presence of various concentrations of gelatin. The resulting ferrosponges show an interconnected nanopore structure which serves as a reservoir to accommodate therapeutic drugs and the nanoporous networks demonstrate magnetic sensitive behavior under the application of magnetic field. The ferrosponges showed high swelling ratios, together with excellent elasticity and hydrophilicity, allow them to response rapidly to an external magnetic stimulation for fast and repeatable swelling-deswelling (or expansion-contractile) operations. The ferrosponges with lower gelatin concentration exhibited good performance on magnetification. Furthermore, drug release from the ferrosponges is relatively magnetic-sensitive and is dominated by its magnetism and associated interaction between the magnetic nanoparticle and the gelatin matrix under an external magnetic field. Higher MNPs concentration in the ferrosponges exhibited higher degree of magnetic sensitive which is due to stronger interparticle forces. By taking these peculiar magnetic sensitive behaviors of the ferrosponges, a novel drug delivery system can be designed for medical uses. (C) 2007 Elsevier B.V. All rights reserved.