Abstract
Liposome is known as one of drug delivery system carriers. The most important factor of liposome for exerting a targeting effect is to have long circulation time in blood stream. For avoiding liposomes from immune system, it is generally used poly(ethylene glycol) (PEG)-lipid which makes aqueous layer around liposomal membrane. In this review, it was summarized our study on some characters of liposome with unique PEG modification, it is focused the relation between fixed aqueous layer thickness (FALT) around liposome and antitumor effect by changing molecular weight of PEG or combination various PEGs.
