STABILIZATION AND ACOUSTIC ACTIVATION OF POLYMERIC MICELLES FOR DRUG DELIVERY

摘要

Methods are disclosed in which a micelle is stabilized against degradation upon dilution. The micelle comprises molecules of a block polymer having a hydrophobic block and a hydrophilic block. The hydrophobic block forms a core of the micelle with corona from the hydrophilic block. The methods for stabilizing the core are (1) by chemically cross-linking, (2) incorporating a hydrophobic oil (vegetable oil) in the core to render it more hydrophobic and stable, and (3) incorporating a cross-linked interpenetrating network of a stimuli-responsive hydrogel into the core. The hydrogel is responsive to any stimuli, but preferably temperature or pH. A substance such as drugs can be incorporated into the dense inner core of the micelles. When subjected to ultrasound, the micelles release the substance, and then reversibly revert to a stable dense core and re-encapsulating the substance when the ultrasound is turned off. By pulsing the ultrasound, it is therefore, to controllably release the substance in a pulsed manner corresponding to the ultrasound signal.