Dual-targeting liposomes with active recognition of GLUT and αβ for triple-negative breast cancer.

At present, chemo- and radiotherapies remain to be the mainstream methods for treating triple-negative breast cancer (TNBC), which is known for poor prognosis and high rate of mortality. Two types of novel dual-targeting TNBC liposomes (Fru-RGD-Lip and Fru+RGD-Lip) that actively recognize both fructose transporter GLUT and integrin αβ were designed and prepared in this work. Firstly, a Y-shaped Fru-RGD-chol ligand, where a fructose and peptide Arg-Gly-Asp (RGD) were covalently attached to cholesterol, was designed and synthesized. Then, the Fru-RGD-Lip was constructed by inserting Fru-RGD-chol into liposomes, while Fru+RGD-Lip was obtained by inserting both Fru-chol and RGD-chol (with the molar ratio of 1:1) into liposomes. The particle size, zeta potential, encapsulation efficiency and serum stability of the paclitaxel-loaded liposomes were characterized. The results indicated that the paclitaxel-loaded Fru-RGD-Lip had the strongest growth inhibition against GLUT and αβ overexpressed MDA-MB-231 and 4T1 cells. The cellular uptake of Fru-RGD-Lip on MDA-MB-231 cells and 4T1 cells was 3.19- and 3.23-fold more than that of the uncoated liposomes (Lip). The uptake of Fru+RGD-Lip was slightly lower, giving a 2.81- and 2.90-fold increase than that of Lip in two cell lines, respectively. The mechanism study demonstrated that the cellular uptake of both dual-targeting liposomes was likely to be recognized and mediated by GLUT and αβ firstly, then endocytosed through comprehensive pathways in an energy-dependent manner. Moreover, Fru-RGD-Lip displayed the maximum accumulation, which was 2.62-fold higher than that of Lip for instance, at the tumor sites compared to other liposomes using in vivo imaging. Collectively, the liposomes co-modified by fructose and RGD have enormous potential in the development of targeted TNBC treatment, especially the covalently modified Fru-RGD-Lip, making it a promising multifunctional liposome.