TY - JOUR A1 - Rudolph, C. A1 - Sieverling, N. A1 - Schillinger, U. A1 - Lesina, E. A1 - Plank, C. A1 - Thünemann, Andreas A1 - Schönberger, H. A1 - Rosenecker, J. T1 - Thyroid hormone (T3)-modification of polyethyleneglycol (PEG)-polyethyleneimine (PEI) graft copolymers for improved gene delivery to hepatocytes N2 - Targeting of gene vectors to liver hepatocytes could offer the opportunity to cure various acquired and inherited diseases. Efficient gene delivery to the liver parenchyma has been obscured from efficient targeting of hepatocytes. Here we show that the thyroid hormone, triiodothyronine (T3), can be used to improve the gene transfer efficiency of nonviral gene vectors to hepatocytes in vitro and to the liver of mice in vivo. T3 conjugated to the distal ends of fluorescent labeled PEG-g-dextran resulted in T3-specific cellular endosomal uptake into the hepatocellular cell line HepG2. PEG-g-PEI graft copolymers with increasing molar PEG-ratios were synthesized, complexed with plasmid DNA, and transfected into HepG2 or HeLa cells. Gene transfer efficiency decreased as the number of PEG blocks increased. T3 conjugation to PEI and the distal ends of PEG blocks resulted in T3 specific gene transfer in HepG2 cells as evidenced by reduction of gene transfer efficiency after pre-incubation of cells with excess of T3. In vivo application of T3-PEG-g-PEI based gene vectors in mice after tail vein injection resulted in a significantly 7-fold increase of gene expression in the liver compared with PEG-g-PEI based gene vectors. KW - Nonviral KW - PEI KW - Gene transfer KW - Thyroid hormone KW - T3 KW - Liver PY - 2007 SN - 0142-9612 VL - 28 IS - 10 SP - 1900 EP - 1911 PB - Elsevier CY - Oxford AN - OPUS4-14521 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -