Spatial and temporal control of drug release through pH and alternating magnetic field induced breakage of Schiff base bonds

P(DEGMA-co-OEGMA-b-[TMSPMA-co-VBA])@silica@magnetite polymer-nanoparticle composites have been developed as a platform for controllable drug release. The nanocomposite facilitates controllable release of therapeutic molecules through breakage of pH and heat labile Schiff base bonds that bind the molecules to the polymer. This enables dual-stimuli responsive drug release in response to the acidic microenvironment of cancerous cells and heat generated by the magnetite nanoparticles when subjected to an alternating magnetic field, thereby permitting spatial and temporal control over 'burst' release of the drugs. The nanocomposite has also been shown to be effective at improving magnetic resonance imaging contrast through enhancement of spin-spin relaxivity.