title: A detachable coating of cholesterol-anchored PEG improves tumor targeting of cell-penetrating peptide-modified liposomes.
abstract: Cell-penetrating peptides (CPPs) have been widely used to enhance the membrane translocation of various carriers for many years, but the non-specificity of CPPs seriously limits their utility in vivo. In this study, cholesterol-anchored, reduction-sensitive PEG (first synthesized by our laboratory) was applied to develop a co-modified liposome with improved tumor targeting. Following optimization of the formulation, the in vitro and in vivo properties of the co-modified liposome were evaluated. The co-modified liposome had a much lower cellular uptake and tumor spheroid uptake, but a much higher tumor accumulation compared to CPP-modified liposome, indicating the non-specific penetration of CPPs could be attenuated by the outer PEG coating. With the addition of exogenous reducing agent, both the in vitro and in vivo cellular uptake was markedly increased, demonstrating that the reduction-sensitive PEG coating achieved a controllable detachment from the surface of liposomes and did not affect the penetrating abilities of CPPs. The present results demonstrate that the combination of cholestervsitive PEG and CPPs is an ideal alternative for the application of CPP-modified carriers in vivo.
authors.affiliation: Key Laboratory of Drug Targeting and Drug Delivery Systems, Ministry of Education, West China School of Pharmacy, Sichuan University, Chengdu 610041, China.
authors.forename: Jie
authors.initials: J
authors.lastname: Tang
authors.affiliation: Key Laboratory of Drug Targeting and Drug Delivery Systems, Ministry of Education, West China School of Pharmacy, Sichuan University, Chengdu 610041, China.
authors.forename: Li
authors.initials: L
authors.lastname: Zhang
authors.affiliation: Key Laboratory of Drug Targeting and Drug Delivery Systems, Ministry of Education, West China School of Pharmacy, Sichuan University, Chengdu 610041, China.
authors.forename: Han
authors.initials: H
authors.lastname: Fu
authors.affiliation: Key Laboratory of Drug Targeting and Drug Delivery Systems, Ministry of Education, West China School of Pharmacy, Sichuan University, Chengdu 610041, China.
authors.forename: Qifang
authors.initials: Q
authors.lastname: Kuang
authors.affiliation: Key Laboratory of Drug Targeting and Drug Delivery Systems, Ministry of Education, West China School of Pharmacy, Sichuan University, Chengdu 610041, China.
authors.forename: Huile
authors.initials: H
authors.lastname: Gao
authors.affiliation: Key Laboratory of Drug Targeting and Drug Delivery Systems, Ministry of Education, West China School of Pharmacy, Sichuan University, Chengdu 610041, China.
authors.forename: Zhirong
authors.initials: Z
authors.lastname: Zhang
authors.affiliation: Key Laboratory of Drug Targeting and Drug Delivery Systems, Ministry of Education, West China School of Pharmacy, Sichuan University, Chengdu 610041, China.
authors.forename: Qin
authors.initials: Q
authors.lastname: He
keywords: Cell penetrating peptide; Cholesterol; Liposome; Reduction-sensitive PEG; Tumor targeting