The invention relates to novel lipid-based nanoparticles (liposomes) for use in targeted, on demand and on site drug delivery. The particles include a wall surrounding a cavity, wherein the wall is comprised of:
phosphoethanolamine-N-[methoxy(polyethylene glycol)-2000] (DSPE-PEG2000), and
The photosensitive lipid nanoparticles are capable of containing water-soluble agents (e.g., topotecan) in their cavity and designed to be 80-200nm in diameter. The release of agents is triggered by the disruption of the lipid bilayer when light (near-infrared wavelength of 650-670nm) is discretely applied. The concurrent activation of the photosensitizing agent, HPPH may be advantageous in the treatment of certain cancers, especially since this agent possesses therapeutic ability. The inventors have also shown the cytotoxicity of the lipid nanoparticles in T24 bladder cancer cells in the presence and absence of light, drug, and HPPH. The lipid nanoparticles containing the water-soluble agent, topotecan, and HPPH, in the presence of light exhibit superior toxicity as compared to either lipid-nanoparticle encapsulated topotecan or HPPH alone.