Pulsatile Drug Release from PLGA Hollow Microspheres by Controlling the Permeability of Their Walls with a Magnetic Field

Pulsatile release: When a high-frequency magnetic field is applied, heat will be generated by coupling to the iron oxide nanoparticles encapsulated in the shells of PLGA hollow microspheres. As the temperature approaches the Tg of PLGA, the polymer chains become more mobile, subsequently increasing the free volume of PLGA matrix and significantly enhancing the diffusion of drug molecules.