Tyrosine modified irinotecan-loaded liposomes capable of simultaneously targeting LAT1 and ATB0,+ for efficient tumor therapy

Abstract

As the demand for nutrients in malignant proliferation of tumors increases, the L-type amino acid transporter 1(LAT1) and amino acid transporter B^0,+ (ATB^0,+) of tumor cells are more highly expressed than normal cells which can be used as new targets for active targeting of cancer. However, drug delivery systems often require multi-target design to achieve simultaneous targeting of different receptors or transporters due to the heterogeneity of the tumor. Here we utilized triethylamine-sucrose octasulfate gradient to actively encapsulate irinotecan into the introliposomal aqueous phase. Targeted ability was achieved through inserting different amino acids modified polyethylene glycol monostearate into the liposomes, and found that glutamate-liposomes can be targeted to LAT1, lysine-liposomes can be targeted to ATB^0,+, and inspiringly, tyrosine-liposomes can be simultaneously targeted to LAT1 and ATB^0,+. The tyrosine-modified liposomes showed the highest cellular uptake in BxPC-3 and MCF-7 cells which were highly expressed both LAT1 and ATB^0,+. Moreover, we validated their targeting capabilities and elucidated the transport mechanism of LAT1 and ATB^0,+-mediated endocytosis. The tumor inhibition rate of tyrosine-modified liposomes greatly increased from 39% to 87% compared with commercially available liposomes loaded CPT-11(Onivyde®). Overall, it showed a good application prospect for efficient tumor therapy and industrial production.

Keywords: ATB(0,+); Active drug loading; Amino acid transporter; CPT-11; Dual-targeted liposomes; LAT1.