Preparation of a novel magnetic and thermo-responsive composite and its application in drug release

Abstract A novel hyperbranched multi-arms star block copolymer with magnetic oriented target and thermo-responsive characters was synthesized. The atom transfer radical polymerization initiators were anchored on the surfaces of magnetic mesoporous silica by the chemical reaction of surface-modified amides with α -bromoisobutyryl bromide. The composites (Fe x O y @SBA-15@HPCMS-g-PNIPAAm) with magnetic mesoporous silica nanoparticles as core and hyperbranched star block copolymers as arms were prepared by iron(III)-mediated surface-initiated polymerization with FeCl 3 ·6H 2 O as catalyst, PPh 3 as ligand, ascorbic acid as reducing agent, N , N -dimethylformamide as solvent, and 4-chloromethylstyrene (CMS) and N -isopropylacrylaminde (NIPAAm) as monomer, respectively. The resultant materials were characterized by Fourier transform infrared, thermogravimetric analysis, N 2 adsorption/desorption measurements, scanning electron microscopy, transmission electron micrographs, differential scanning calorimeter, and vibrating sample magnetometer. With aspirin as model drug, the drug release behavior of the hybrid materials was investigated in detail. Due to both the thermo-responsive and the magnetic property, the product may be used as a drug delivery system aiming at a cancer treatment. Graphical abstract