cyclic peptide containing one cysteine and five alternating tryptophan and arginine\namino acids [(WR)5C] was synthesized using Fmoc/tBu solid-phase methodology. The ability of the\nsynthesized cyclic peptide to produce gadolinium nanoparticles through an in situ one-pot mixing of\nan aqueous solution of GdCl3 with [(WR)5C] peptide solution was evaluated. Transmission electron\nmicroscopy showed the formed peptide-Gd nanoparticles in star-shape morphology with a size\nof ~250 nm. Flow cytometry investigation showed that the cellular uptake of a cell-impermeable\nfluorescence-labeled phosphopeptide (F0-GpYEEI, where F0 = fluorescein) was approximately six\ntimes higher in the presence of [(WR)5C]-Gd nanoparticles than those of F0-GpYEEI alone in human\nleukemia adenocarcinoma (CCRF-CEM) cells after 2 h incubation. The antiproliferative activities\nof cisplatin and carboplatin (5 microM) were increased in the presence of [(WR)5C]-GdNPs (50 microM) by\n41% and 18%, respectively, after 72-h incubation in CCRF-CEM cells. The intracellular release of\nepirubicin, an anticancer drug, from the complex showed that 15% and 60% of the drug was released\nintracellularly within 12 and 48 h, respectively. This report provides insight about using a non-toxic\nMRI agent, gadolinium nanoparticles, for the delivery of various types of molecular cargos.
Loading....