Surfactant‐Free, Self‐Assembled PVA‐Iron Oxide/Silica Core–Shell Nanocarriers for Highly Sensitive, Magnetically Controlled Drug Release and Ultrahigh Cancer Cell Uptake Efficiency

Abstract

Surfactant‐free, self‐assembled iron oxide/silica core–shell (SAIO@SiO2) nanocarriers were synthesized as bifunctional magnetic vectors that can be triggered for the controlled release of therapeutic agents by an external magnetic field. In addition, drug release profiles can be well‐regulated through an ultrathin layer of silica shell. The hydrophobic drug molecules were encapsulated within the iron oxide‐PVA core and then further covered with a thin‐layer silica shell to regulate the release pattern. Remote control of drug release from the SAIO@SiO2 nanocarriers was achieved successfully using an external magnetic field where the core phase being structurally disintegrated to a certain extent while subjected to magnetic stimulus, resulting in a burst release of the encapsulated drug. However, a relatively slow and linear release restored immediately, directly after removal of the stimulus. The nanostructural evolution of the nanocarriers upon the stimulus was examined and the mechanism for controlled drug release is proposed for such a core–shell nanocarrier. Surprisingly, the surfactant‐free SAIO@SiO2 nanocarriers demonstrated a relatively high uptake efficiency from the HeLa cell line. Together with a well‐regulated controlled release design, the nanocarriers may provide great advantages as an effective cell‐based drug delivery nanosystem for biomedical applications.

Temperature responsive hydrogel magnetic nanocomposites for hyperthermia and metal extraction applications

“…Magnetic fluid hyperthermia is a type of cancer therapy in which cancer cells are killed by raising the cell temperature above 44°C, utilizing the heat dissipated from magnetic nanoparticles [43,44]. Recently, the use of magnetic sensitive hydrogels has been explored for hyperthermia applications [45][46][47][48].…”

“…Furthermore, hydrogels can be modified with new functional groups or prepared as composites to increase their metal absorption capacity and their versatility for practical usage [39,40]. Similarly magnetic separation has become a promising method for environmental purification as it produces no contamination and can easily separate toxic metals from the aqueous medium under applied magnetic field [37,[41][42][43][44]. Hence, hydrogels with magnetic properties have become a new class of intelligent materials which attract interest as absorbents for the removal of toxic materials from the aquatic media [39].…”

Templated preparation of porous magnetic microspheres and their application in removal of cationic dyes from wastewater

“…Magnetic nanoparticles (MNPs) are currently being intensively investigated because of their extensive applications such as drug release [1][2][3][4], magnetic resonance imaging [5][6][7][8], biological separation [9,10] and water purification [11,12]. Among them, water purification with magnetic materials is a new research subject, which was reported by only a few papers.…”

Selective preparation of novel fluoroalkyl end-capped co-oligomeric nanocomposite-encapsulated magnetites and magnetite-adsorbing co-oligomeric nanoparticles

“…Much attention has been devoted recently to well-dispersed magnetic colloidal particles, owing to the broad range of potential applications in the fields of ferrofluids, 1,2 high-density data storage, 3 disks and toner in printing, [4][5][6] magnetic resonance imaging, 7,8 enzyme immobilization, 9 rapid biological separation, 10,11 drug delivery, [12][13][14] biomedical materials, [15][16][17] immunoassays 18,19 and biosensors. 20,21 The development of colloidal-stable magnetic nanoparticles is essential from a practical point of view.…”