Vitamin E TPGS modified liposomes enhance cellular uptake and targeted delivery of luteolin: An in vivo/in vitro evaluation

Luteolin (LUT) is an active agent in cancer prevention and a potential candidate for clinical chemotherapy. However, poor water solubility and extensive excretion have limited the clinical use of luteolin. Herein, we attempted to develop vitamin E d-α-tocopherol acid polyethylene glycol 1000 succinate (TPGS) coated liposomes to improve the accumulation of luteolin in lung cancer. Luteolin or coumarin-6 loaded liposomes were prepared using film-dispersion methods and characterized according to their particle size, polydispersity, zeta potential, and drug encapsulation efficiency. Cellular uptake properties and cytotoxicities of luteolin or coumarin-6 loaded liposomes were determined in A549 cells. Optical in vivo imaging was employed as a method of assessing tumor targeting. The antitumor effect was evaluated in mice xenotransplanted with A549 cancer cells. The results showed that TPGS coated liposomes are spherical, and are ∼176.2nm in size. TPGS coated liposomes enhanced cellular uptake and apoptosis by upregulating the Bax/Bcl-2 ratio, resulting in improved cytotoxicity in A549 cells. TPGS coated liposomes significantly accumulated in tumor tissue and enhanced tumor inhibition without altering the structures of other organs. Thereby, TPGS coated liposomes provide an effective strategy in cancer chemotherapy for model drugs with poor water solubility such as luteolin.