Activated polyamidoamine dendrimers, a non-viral vector for gene transfer to the corneal endothelium

We investigated the efficiency of activated polyamidoamine dendrimers, a ne w class of nonviral vectors, to transfect rabbit and human corneas in ex vi vo culture. In addition ib assessing the expression of a marker gene we hav e demonstrated that this approach can be used to induce the pro; production of TNF receptor fusion protein (TNFR-lg), a protein with therapeutic poten tial. Whole thickness rabbit or human corneas were transected ex vivo with complexes consisting of dendrimers and plasmids containing lacZ or TNFR-lg genes. Following optimisation 6-10% of the corneal endothelial cells expres sed the marker gene. Expression was restricted to the endothelium and was m aximal after transfection with 18:1 (W/W) activated dendrimer:plasmid DNA r atio and culture for 3 days, The supernatant of corneas transfected with TN FR-lg plasmid contained TNFR-lg protein which was able to inhibit TNF-media ted cytotoxicity in a bioassay We have therefore shown that activated dendr imers are an efficient nonviral vector capble of transducing corneal endoth elial cells ex vivo. They may have applications in gene-based approaches ai med at prevention of corneal allograft rejection or in treatment of other d isorders of corneal endothelium.