Modification of commercial liposomal drug carrier by plasmon resonant coating

Multiple liposomal drugs have been successfully marketed as pharmaceuticals within the past two decades. Some of these clinically approved drugs, Doxil® in particular, have been shown to selectively localize within tumors due to the enhanced permeability and retention effect. However, a limitation exists with the inability to control content release once the drug gets to the desired location. Here we investigated the ability to apply a plasmon resonant coating to commercially available Doxil with the intention of spatially and temporally controlling doxorubicin release. While Doxil was successfully gold coated with a maximum plasmon resonant peak at 631 nm, the release at elevated temperature and on exposure to light was less than 10%. This result is similar to that observed for uncoated Doxil. Decreasing the pH had the same effect on both uncoated and plasmon resonant sample where a 10% increase in release was observed after samples were exposed to elevated temperature. Development of a highly efficient mechanism of light-activated drug release from Doxil will require a temperature-sensitive lipid composition.