There is provided herein a nanovesicle comprising a monolayer of phospholipid, porphyrin-phospholipid conjugate and a peptide encapsulating a hydrophobic core, wherein the peptide comprises an amino acid sequence capable of forming at least one amphipathic α-helix； the porphyrin-phospholipid conjugate comprises one porphyrin, porphyrin derivative or porphyrin analog covalently attached to a lipid side chain, preferably at the sn-1 or the sn-2 position, of one phospholipid； the molar % of porphyrin-phospholipid conjugate to phospholipid is 35% or less； the nanovesicle is 35 nm in diameter or less.
