Provided herein is a liposome comprising: a) a conjugate comprising a lysophospholipid and a photosensitizer b) a first derivatized phospholipid comprising a first phospholipid and a strained cyclooctyne moiety c) a second derivatized phospholipid comprising a second phospholipid and a polyethylene glycol polymer and d) a cationic or anionic lipid. Also provided herein is a liposome comprising: a) a conjugate comprising a lysophospholipid and a photosensitizer b) a first derivatized phospholipid comprising a first phospholipid and a targeting moiety c) a second derivatized phospholipid comprising a second phospholipid and a polyethylene glycol polymer and d) a cationic or anionic lipid. The liposomes provided herein can be used, for example, in the treatment of cancer or in the imaging of cancer tumors.
