PEGylated peptide based reductive polycations as efficient nonviral gene vectors.

To overcome the critical barriers in gene delivery, a series of reducible polycations (RPCs) based on low molecular weight (LMW) peptides, i.e. PolyHK6 H, PolyHK6 H-mPEG1 , PolyHK6 H-mPEG2 , and PolyHK6 H-mPEG3 , with different poly(ethylene glycol) (PEG) contents, are synthesized and evaluated as nonviral gene vectors.

Tyroserleutide-based gene vector for suppressing VEGF expression in cancer therapy.

A small interfering RNA (siRNA) plasmid DNA (pYr-1.1-hU6-EGFP-siVEGF) was constructed and used for suppressing vascular endothelial growth factor (VEGF) expression and inhibiting tumor growth. Then, a (tyrosyl-seryl-leucine)-polyethyleneimine-poly(ethylene glycol) (YSL-PEI-PEG) conjugate was designed and synthesized as a gene carrier for the delivery of pYr-1.

A linear-dendritic cationic vector for efficient DNA grasp and delivery.

This paper presents an attempt to design an efficient and biocompatible cationic gene vector via structural optimization that favors the efficient utilization of amine groups for DNA condensation. To this end, a linear-dendritic block copolymer of methoxyl-poly(ethylene glycol)-dendritic polyglycerol-graft-tris(2-aminoethyl)amine (mPEG-DPG-g-TAEA) was prepared with specially designed multiple functions including strong DNA affinity, endosomal buffering and expected serum-tolerance. Based on the transfection in serum-free and serum-conditioned media, the influences of the polymer structures including the degree of polymerization of DPG and TAEA substitution degree were explored.

Enhanced nuclear import and transfection efficiency of TAT peptide-based gene delivery systems modified by additional nuclear localization signals.

Cellular uptake and nuclear localization are two major barriers in gene delivery. In order to evaluate whether additional nuclear localization signals (NLSs) can improve gene transfection efficiency, we introduced different kinds of NLSs to TAT-based gene delivery systems to form three kinds of complexes, including TAT-PV/DNA, TAT/DNA/PV, and TAT/DNA/HMGB1. The DNA binding ability of different vectors was evaluated by agarose gel electrophoresis.

Targeted delivery in breast cancer cells via iodine: nuclear localization sequence conjugate.

The nonviral vector with iodine-nuclear localization sequence (namely, NLS-I) targeting breast cancer cells was fabricated. Ternary complexes were formed via charge interactions among NLS-I peptides, PEI 1800, and DNA, and we investigated their cellular internalization, nuclear accumulation as well as transfection efficiency. All the experiments were assessed by employing MCF-7 cells that express sodium/iodide symporter and HeLa cells that lack the expression of the symporter.