Synthesis and cellular characterization of various nano-assemblies of cell penetrating peptide-epirubicin-polyglutamate conjugates for the enhancement of antitumor activity

Abstract

A new class of cell penetrating peptides (CPPs) named peptide amphiphile was designed to improve the intracellular uptake and antitumor activity of epirubicin (EPR). Various amphiphilic CPPs were synthesized by solid phase peptide synthesis method and were chemically conjugated to EPR. Their corresponding nanoparticles (CPPs-E4 and CPPs-E8)were prepared via non-covalent binding of the peptides and polyanions. Cytotoxicity and anti-proliferative activity were evaluated by MTT assay. Cellular uptake was examined by flow cytometry and fluorescence microscopy. The CPPs exhibited slight cytotoxicity.Binding of polyglutamate to CPPs (CPPs-E4 and CPPs-E8 nanoparticles) decreased their cytotoxicity. CPPs-E8 nanoparticles showed lower cytotoxicity than CPPs-E4 nanoparticles.Cellular uptake of K3W4K3-E8, K2W4K2-E8 and W3K4W3-E8 reached 100% with no difference between each of the mentioned CPPs and its nanoparticle at 50 µM. The antiproliferative activity of EPR was enhanced following conjugation to peptides and nanoparticles at 25 µM. CPPs-EPR-E4 and -E8 nanoparticles displayed higher antiproliferative activity than CPPs-EPR at 25 µM. CPPs-E8-EPR nanoparticles showed higher anti-proliferative activity than CPPs-E4-EPR. K3W4K3-E8-EPR nanoparticles exhibited the highest anti-proliferative activity at 25 µM. The synthesized peptide nanoparticles are proposed as suitable carriers for improving the intracellular delivery of EPR into tumor cells with low cytotoxicity and high antitumor activity.

Nanoparticle-based drug delivery in the inner ear: current challenges, limitations and opportunities

“…For example, to increase the penetration of NPs into the cochlea, NPs can be conjugated to cell penetrating peptides [76]. The antitumor activity of drug epirubicin (EPR) has been shown to be enhanced following conjugation of drug loaded NPs with cell penetrating peptides [77]. These findings hold a great potential to improve the penetration of drug loaded NPs into the cochlea.…”

Effects of N-terminal and C-terminal modification on cytotoxicity and cellular uptake of amphiphilic cell penetrating peptides

“…All peptides were synthesized manually by solid phase peptide synthesis (SPPS) method on CTC resin by Fmoc strategy using 60 ml innovative polypropylene syringes equipped with poly-tetrafluoroethylene (PTFE) filters, a Teflon stopcock and stopper [13][14][15][16]. The Fmoc protected amino acids with different side chain protecting groups used as the following derivatives: Fmoc-Arg (Pbf)-OH, Fmoc-Trp (Boc)-OH, Fmoc-Lys (Boc)-OH, Fmoc-Gly-OH, Fmoc-Gln (Trt)-OH and Fmoc-Glu (OtBu)-OH.…”

Peptide-Based siRNA Nanocomplexes Targeting Hepatic Stellate Cells

“…Many studies have reported that polyglutamate can effectively reduce the cytotoxicity of cationic cell-penetrating peptides through covalent or non-covalent interaction [ 26 , 27 ]. The length and amount of polyglutamate can be adjusted to prevent toxicity while maintaining cellular uptake efficiency [ 28 ]. Furthermore, negatively charged polyglutamate can be utilized for structure stabilization and surface modification.…”