Preface

Completion of the working draft of human genome has unquestionably strengthened the clinical potential of gene therapy. The principle of gene therapy is simple: “Supplement the body cells with the corrected copies of the malfunctioning genes”. However, given that both the macromolecular genes (DNA) and biological cell surfaces are negatively charged, spontaneous entry of naked DNA inside cells are unlikely to be an efficient process. Thus, efficient delivery and expression of genes into body cells (a process biologists call “transfection”) is always easier said than done. In other words, the problems of developing clinically viable gene therapeutic approach and designing safe and efficient gene delivery reagents are inseparable: shortcomings in one is going to adversely affect the success of the other. Clearly, the realization of the full potential of gene therapy will critically depend on the future development of safe and efficient gene delivery reagents. Transfection vectors commonly used in gene therapy are mainly of two types: viral and non-viral. The efficiencies of viral vectors are, in general, superior to their nonviral counterparts. However, potential adverse immunogenic aftermath associated with the use of viral vectors such as on-set of serious immune response to the expressed viral proteins, innate humoral response, possibility of random integration into the host chromosome & subsequent activation of proto-oncogenes, possibility of systemic clearance due to complement activation, etc. are increasingly making non-viral cationic transfection lipids as the vectors of choice. The cationic transfection lipids have come a long way in its voyage to clinical success. Initial excitements in late eighties and early nineties were followed by a period of set-backs during late nineties in developing clinically viable & systemically stable lipoplexes (complex of lipids and DNA). Breakthrough technical advances in designing stable lipoplexes capable of successfully confronting the daunting systemic challenges are increasingly being reported with the dawning of the new millennium. The guest editor firmly believes that the articles of the present theme issue written by the experts in the field will provide genuine impetus to more and more creative minds across the scientific disciplines towards ensuring clinical success of cationic transfection lipids in gene therapy. At the end, my heart-felt thanks to all the invited contributors for spending so much of their time and efforts for this theme issue.