Lipid-Like Materials for siRNA Delivery: Giving Genes the Silent Treatment

Despite the promise of RNA interference therapeutics, progress towards the clinic has been slowed by the difficulty of delivering short interfering RNA (siRNA) into cellular targets within the body. Over the past four years, a class of lipid-like materials termed ‘lipidoids’ has been studied for applications in siRNA-mediated gene silencing. It has been demonstrated that lipidoids have the potential to achieve therapeutic effect at low siRNA doses in a variety of biological systems in vivo, including hepatocytes, endothelial cells, macrophages, and leukemia and lymphoma cells. Here, I will report on the biological effect of lipidoids as well as the varied mechanisms of action through which these materials can act.