Novel SO3H functionalized magnetic nanoporous silica/polymer nanocomposite as a carrier in a dual-drug delivery system for anticancer therapy

Magnetic nanoporous silica particles (MNS) with spherical morphology and 100 nm particle with advanced characteristics suitable for nanomedicine purposes were synthesized. The obtained nanoparticles were modified with SO3H groups in a two-step post synthesis procedure. An anticancer drug, mitoxantrone (MTX), and an anti-inflammatory drug, prednisolone (PRD), were loaded on the silica support. The mitoxantrone loaded MNS-SO3H nanoparticles were coated by chitosan and then prednisolone was infused in the chitosan layer. A second layer of alginate was then applied around the prednisolone and mitoxantrone containing formulation. All materials were characterized by XRD, N2 physisorption, Mössbauer spectroscopy, magnetization measurements and transmission electron microscopy in order to demonstrate that by the applied preparation method around 11 nm sized maghemite crystals embedded in spherical mesoporous silica nanoparticles were obtained with high pore volume and surface area. Thermal gravimetric analysis, ATR FT-IR spectroscopy and in vitro release experiments proved that MTX and PRD were successfully loaded on the silica matrix. Alginate coating further improved the release properties by preventing the burst release of MTX and PRD. The cytotoxicity properties of the drugs loaded formulations and their ability to retain the intrinsic pharmacological properties of the encapsulated drugs were investigated on a panel of human tumor cell lines.