Branched polyethylenimine (PEI, 25 kDa) was obtained from Sigma-Aldrich. Methoxypolyoxyethylene amine (mPEG-NH2, 5 kDa) and 2-Naphthylacetic acid were obtained from Aladdin (Shanghai, China). 4,4′-bipyridine, methyl iodide and potassium thioacetate were purchased from Sinopharm Chemical Reagent Co., Ltd. 1,10-dibromodecane was purchased from darui finechemical Co., Ltd. Potassium hexafluorophosphate (KPF6), n-Bu4NCl and 3,3′-Dithiodipropionic acid (DTPA) were obtained from Aladdin (Shanghai, China). All other reagents and solvents were of analytical grade and used as received without further purification.
Deoxyribonucleic acid (DNA, fish sperm, sodium salt) were obtained from AMRESCO for physiological measurements such as dynamic light scattering (DLS), zeta potential and transmission electron microscope (TEM). Cy3-labeled DNA (Cy3-DNA) was purchased from Sangon Biotech (Shanghai, China) for cell uptake determination and intracellular trafficking of polyplexes. Plasmid DNA pGL3 was obtained from Promega (USA) for gel retardation assay and gene transfection. 3-(4,5-dimethylthiAzl-2-yl)-2,5-diphenyltetrAzlium bromide (MTT) was obtained from Bio Basic Inc. Loading buffer was purchased from TakaRa Biotechnology (Dalian, China) Co.Ltd. 0.5 × TBE buffer was diluted from 4 × TBE buffer (0.36 M tris-boric acid, 8 mM elhylene diamine tetraacetic acid).
Deoxyribonucleic acid (DNA, fish sperm, sodium salt) were obtained from AMRESCO for physiological measurements such as dynamic light scattering (DLS), zeta potential and transmission electron microscope (TEM). Cy3-labeled DNA (Cy3-DNA) was purchased from Sangon Biotech (Shanghai, China) for cell uptake determination and intracellular trafficking of polyplexes. Plasmid DNA pGL3 was obtained from Promega (USA) for gel retardation assay and gene transfection. 3-(4,5-dimethylthiAzl-2-yl)-2,5-diphenyltetrAzlium bromide (MTT) was obtained from Bio Basic Inc. Loading buffer was purchased from TakaRa Biotechnology (Dalian, China) Co.Ltd. 0.5 × TBE buffer was diluted from 4 × TBE buffer (0.36 M tris-boric acid, 8 mM elhylene diamine tetraacetic acid).