Browsing by Subject "gene transfer"

Gene therapy is an experimental technique that involves inserting therapeutic genes into the target cells to treat diseases. Gene transfer can be performed by ex vivo or in vivo method. Ex vivo method means transferring the therapeutic gene in laboratory to the cells that are removed from the patient, after which the cells are returned to the patient. In the in vivo method the gene transfer is performed directly to the target tissue inside the patient's body. Gene therapy clinical trials have been carried out to treat many diseases. The majority of the clinical trials have so far been cancer trials. Nevertheless, the most promising results have been established in treating diseases that arise from mutations in a single gene, i.e. monogenic diseases. Monogenic diseases include e.g. hemophilia and heritable immunodeficiencies. The biggest challenges in the clinical trials so far have been the limited gene transfer efficiency of the currently used gene vectors, the short duration of the transgene expression and the side-effects in viral-mediated gene transfer. Nonviral gene transfer agents have so far been less efficient in vivo than the viral vectors. This is partly due to the interaction between serum components and nonviral vectors. The main purpose of this study was to investigate the effect of serum to the gene transfer efficiency of a nonviral vector polyethyleneimine PEI22K and the combination of PEI22K and cationic liposome Dosper in vitro in the SMC-cells. The potential synergistic increase in the transfection efficiency of PEI22K/Dosper combination was also studied. The secondary goal in this study was to develop an in vitro model which could be used to predict the gene transfer efficiency of gene vectors in vivo. The combination of PEI22K and Dosper resulted in a synergistic increase in the transfection efficiency in serum-free transfection. In the presence of serum the efficiency of PEI22K was higher than the efficiency of PEI22K/Dosper combination. 1-10% serum concentrations did not significantly affect PEI22K`s transfection efficiency, but dramatically decreased the efficiency of PEI22K/Dosper combination. The results suggest that PEI22K is more suitable than PEI22K/Dosper combination for in vivo gene transfer.