Drug delivery compositions including nanoshells for triggered drug release

A composition for controlled release of a drug comprising:

• a plurality of particles comprising:
• a polymer which is either an amorphous or semi-crystalline polymer with a glass transition temperature as plasticized under physiological conditions from about 40° C. to about 60° C., or a semi-crystalline polymer having a degree of crystallinity of at least 25% with a melting temperature, as plasticized under physiological conditions, from about 40° C. to about 60° C.;
• a drug;
• and
• one or more nanoshells capable of producing heat upon exposure to electromagnetic radiation, a fluctuating magnetic field, or a microwave field;
• wherein
• substantially all of the individual particles of the plurality include one or more of the nanoshells;
• wherein the particles comprise a polymer matrix comprising the polymer and coating the nanoshell;
• or the particles are composed of a polymer matrix comprising the polymer and nanoshells;
• or the particles comprise a polymer matrix comprising the polymer and nanoshells, the polymer matrix surrounding a central core;
• and
• wherein upon exposure to electromagnetic radiation, or a fluctuating magnetic field, or a microwave field, the nanoshells produce sufficient heat to raise the temperature of the polymer above its glass transition temperature or its melting temperature.