(543b) Photothermally Triggered Drug Release From Temperature Sensitive Liposomes

A drug delivery system with rapid contents release under continuous-wave near-infrared (NIR) light will enable precise spatial and temporal control of drug release.  The drug is encapsulated within temperature sensitive liposomes and rapid drug release is triggered by the photothermal heating of hollow gold nanoshells coupled to the liposome surface.  The nanoshells locally heat the liposome membrane to the phase transition temperature, allowing the drug to passively diffuse across the membrane.  The phospholipid composition of the liposome membrane was tuned to control the temperature at which release was initiated and to enhance the rate of release.  Rapid release of 60-70% of the encapsulated contents was observed at physiological temperatures within minutes of irradiation.  This system could be used for cancer therapy to deliver anticancer agents directly to a tumor site.