Design principle of an ideal multifunctional lipid-based nanoparticle for targeted and triggered drug delivery. Liposomes consist of a matrix phospholipid (cyan), a destabilizing (pore forming) phospholipid (yellow), conjugation lipid (green), ligand attached via the conjugation lipid (brown), and a cell death marker such as an apoptotic detector (pink). The nanoparticle is loaded with a chemotherapeutic agent (red) and an imaging agent (blue) in the aqueous milieu.