Gene medicine : A new field of molecular medicine

Gene therapy has emerged as a new concept of therapeutic strategies to trea t diseases which do not respond to the conventional therapies. The principl e of gene therapy is to introduce genetic materials into patient cells to p roduce therapeutic proteins in these cells. Gene therapy is now at the stag e where a number of clinical trials have been carried out to patients with gene-deficiency disease or cancer. Genetic materials for gene therapy are g enerally composed of gene expression system and gene delivery system. For t he clinical application of gene therapy in a way which conventional drugs a re used, researches have been focused on the design of gene delivery system which can offer high transfection efficiency with minimal toxicity. Curren tly, viral delivery systems generally provide higher transfection efficienc y compared with non-viral delivery systems while non-viral delivery systems are less toxic, less immunogenic and manufacturable in large scale compare d with viral systems. Recently, novel strategies towards the design of new non-viral delivery system, combination of viral and non-viral delivery syst ems and targeted delivery system have been extensively studied. The continu ed effort in this area will lead us to develop gene medicine as "gene as a drug'' in the near future.