TPP-dendrimer nanocarriers for siRNA delivery to the pulmonary epithelium and their dry powder and metered-dose inhaler formulations.

The regulation of genes utilizing the RNA interference (RNAi) mechanism via the delivery of synthetic siRNA has great potential in the treatment of a variety of lung diseases. However, the delivery of siRNA to the lungs is challenging due to the poor bioavailability of siRNA when delivered intraveneously, and difficulty in formulating and maintaining the activity of free siRNA when delivered directly to the lungs using inhalation devices. The use of non-viral vectors such as cationic dendrimers can help enhance the stability of siRNA and its delivery to the cell cytosol.