One-pot construction of doxorubicin conjugated magnetic silica nanoparticles

Abstract

Doxorubicin (DOX) conjugated magnetic silica nanoparticles (DOX–Fe₃O₄–SiO₂) are successfully fabricated using a new one-pot method without need for the process of inconvenient multistep synthesis in advance, based on the condensation of DOX and the silica precursor 3-isocyanatopropyltriethoxysilane (ICPTES), followed by the spontaneous formation of a silica coating onto the surface of Fe₃O₄nanoparticlesvia sol–gel polymerization of triethoxysilane. Mass spectroscopy provides evidence that doxorubicin is conjugated to ICPTES via a urea bond (–NHCONH–) via the reaction of the amino groups of DOX with the isocyanate group (–NCO) of ICPTES in water. The obtained magnetic nanoparticles are well dispersed. Their mean diameter is about 66.9 nm with a narrow size distribution. The conjugated DOX–SiO₂–Fe₃O₄nanoparticles exhibited a higher loading efficiency of 60.5 ± 3.7% and a more sustained release profile than SiO₂nanoparticles containing physically-entrapped DOX. It is anticipated that fine-tuning of other drugs or bioactive molecules containing –NH₂groups to Fe₃O₄/SiO₂nanoparticles would foster innovative avenues for the development of smart drug delivery and controlled release systems.