The aim of the present study was to develop and assess an integrin-targeted synthetic vector system for the transfection of haematopoietic cell lines and dendritic cells. The vector consists of a cationic liposome, Lipofectin (L), a peptide that both targets integrins and binds to DNA (I) and plasmid DNA (D). These components interact electrostatically to form the LID vector complex. Transfection conditions were optimized for the ratio of vector components, the amount of DNA and transfection incubation time. The kinetic analysis of transgene expression revealed a peak of activity at about 24 h, followed by a rapid decline over the next 48 h. Targeted gene delivery was demonstrated by comparing transfected luciferase reporter gene levels using LID complexes containing integrin-targeting peptide sequences with a control peptide. In addition, transfection levels of integrin-targeted LID complexes were significantly enhanced by treatment of cells with PMA, which was also shown to activate integrin receptors and enhance binding to fibronectin. Under optimized conditions transfection efficiencies of 19% for TF-1 cells, 28% for Jurkat cells and 10% for primary dendritic cells were achieved. The LID vector may thus find application for gene-transfer experiments in haematopoietic cell lines and for the development of genetic vaccines using transfected dendritic cells.