Among the approaches under development is the use of novel stents for the transfer of genes for long-term gene expression in the coronary circulation. Ultimately, these approaches will be used for other potentially beneficial genes. For those diseases of autoimmunity or connective tissue with defined genetic abnormalities, gene replacement or supplementation therapy will be the ultimate goal. The molecular neurobiology of neurotrophic factors, which promote neuronal survival and maintenance of new growth of the axons and dendrites is becoming better understood. The therapeutic trials of neurotrophic agents for various central and peripheral nervous systems degenerative diseases have been proposed and in some cases are being initiated.
Research projects are focused on developing methods for gene delivery to muscle.
In addition, methods for more efficient transplantation of fetal myoblasts as a means of delivery exogenous genes are being developed. Finally, by developing animal models and an HSV vector system carrying the dystrophin gene, we are investigating methods for experimental therapy for Duchenne muscular dystrophy. Minimally these include an understanding of the pathobiology of the disease state for which gene therapy is envisioned, identification of the target tissue and cell type for gene transfer, the development of a suitable gene-transfer vehicle such as a virus vector, and suitable cellular and animal models for testing the efficacy of the intended therapy. One of the most difficult of these criteria relates to gene transfer methods and vehicles, which probably represents the fundamental obstacle to making gene therapy a reality. The vector development program is working on a number of different viral transfer systems including retroviruses, adenoviruses, herpes simplex viruses, adeno-associated viruses, and picornaviruses.