http://repub.eur.nl/res/aut/7794/ List of Publications en http://repub.eur.nl/static-eur/img/logo.png http://repub.eur.nl http://repub.eur.nl/res/pub/7342/ 2004-10-06T00:00:00Z Gene delivery and therapy in general The concept of gene therapy is a promising approach towards clinical treatment of pathological processes. The underlying principle of gene therapy is based on the introduction of genetic material into living cells in order to achieve a therapeutic biological effect [1]. Generally, this involves introducing DNA encoding a gene for a therapeutic protein. In somatic gene therapy the target cells are not part of the germ line and therefore the effects are restricted to the individual. In contrast, in germ line gene therapy the egg or sperm cells are manipulated and thus the potential future offspring of the individual are effected. For this reason, germ line gene therapy is not permitted under current legislation [2]. Gene therapy offers the potential of correcting the underlying cause of hereditary monogenetic diseases such as cystic fibrosis (CF) [3] and haemophilia B [4], for which the responsible gene is known. Therapeutic benefits of gene therapy can be expanded to a wide range of diseases that are not strictly hereditary, such as cancer [5] and cardiovascular diseases [6]. In addition, applications of gene therapy can reach much further: introducing disease-modifying genes into already dysfunctional organs may alter the course of disease [7]. When an infectious agent is involved, gene therapy can be directed towards elimination of the agent from the organism or towards prevention of infection in the form of vaccination [8]. Recent developments indicate that besides delivery of dsDNA, other applications such as delivery of RNA sequences, RNAi, and RNA decoys that bind regulatory proteins [9] offers potential. For example, infectious agents such as HIV [10] and Hepatitis C virus [11] are targets for the development of RNAi for virus inhibition.