An update on angiogenic gene therapy: vascular endothelial growth factor and other directions.

Therapeutic angiogenesis is a promising new concept for the treatment of tissue ischemia and other related medical conditions or processes, such as wound healing. Members of the vascular endothelial growth factor (VEGF) family are among the most powerful modulators of vascular growth; they regulate vascular growth and maintenance during embryogenesis and in adults. Despite progress in basic research and preclinical animal studies of therapeutic angiogenesis, significant problems still exist in translating experimental findings into beneficial clinical approaches. This review summarizes these problems and highlights recent findings in the field of therapeutic angiogenesis using VEGF and other factors, with special reference to potential clinical applications. Also, in order to better optimize vectors, doses and treatment approaches, it is proposed that the analysis of new parameters is introduced. These parameters consist of: i) spreading throughout and reaching appropriate cells in the target tissue, ii) transfection efficiency, iii) expression strength, and iv) duration of expression. It is envisaged that this 'STED' analysis will aid the clinical development of gene therapy.