Multifunctional peptide conjugated amphiphilic cationic copolymer for enhancing ECs targeting, penetrating and nuclear accumulation

Gene therapy has drawn great attention in the treatments of many diseases, especially for cardiovascular diseases. However, the development of gene carriers with low cytotoxicity and multitargeting function is still a challenge. Herein, the multitargeting REDV-G-TAT-GNLS peptide was conjugated to amphiphilic cationic copolymer poly(epsilon-caprolactone-co-3(S)-methyl-morpholine-2,5-dione)-g-polyethyleneimine (PCLMD-g-PEI) via a heterobifunctional orthopyridyl disulfide-poly(ethylene glycol)-N-hydroxysuccinimide (OPSS-PEG-NHS) linker to prepare PCLMD-g-PEI-PEG-REDV-G-TAT-G-NLS copolymers with the aim to develop the gene carriers with low cytotoxicity and high transfection efficiency. The multitargeting micelles were prepared from PCLMD-g-PEI-PEG-REDV-G-TAT-G-NLS copolymers by selfassembly method and used to load pEGFP-ZNF580 plasmids (pDNA) to form gene complexes for enhancing the proliferation and migration of endothelial cells (ECs). The loading pDNA capacity was proved by agarose gel electrophoresis assay. These multitargeting gene complexes exhibited low cytotoxicity by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay. The high internalization efficiency of these gene complexes was confirmed by flow cytometry. The results of in vitro transfection demonstrated that these multitargeting gene complexes possessed relatively high transfection efficiency. The rapid migration of ECs transfected by these gene complexes was verified by wound healing assay. Owing to ECs-targeting ability, cell-penetrating ability and nuclear targeting capacity of REDV-G-TAT-G-NLS peptide, the multitargeting polycationic gene carrier with low cytotoxicity and high transfection efficiency has great potential in gene therapy.