Non-viral strategies for transfection of the corneal endothelium

Corneal endothelial dysfunction is a major cause of visual impairment worldwide and the leading indication for corneal transplantation. The persistent shortage of donor tissue has accelerated the search for alternative cell-based strategies to restore corneal endothelial function. Non-viral nucleic acid (NA) delivery offers a versatile and safer platform than viral vectors for modulating endothelial cell proliferation, survival, and function. This review summarizes current non-viral transfection approaches applied to corneal endothelial cells, focusing on both physical and biochemical techniques. Physical methods such as electroporation and nanoneedles provide direct cytosolic access but vary widely in efficiency and cytotoxicity. Electroporation achieves high in vivo delivery but at the cost of tissue damage, while nanoneedles show high ex vivo efficiency with minimal toxicity. Biochemical carriers such as lipid-based systems, polyethylenimine, peptides, dendrimers, magnetic lipoplexes, and calcium phosphate nanoparticles enable efficient gene transfer in vitro and ex vivo, though endosomal escape and in vivo specificity remain limiting factors. Overall, while no single approach yet meets all clinical requirements, continuous advances in nanomaterial design, targeting strategies, and NA chemistry are progressively bridging the gap toward safe and effective corneal endothelial gene therapy.