394d pH-Triggered Liposomes for Rnai Delivery

Debra Auguste, Harvard University, 29 Oxford St, Cambridge, MA 02138 and Robert Langer, Chemical Engineering and Biological Engineering, Massachusetts Institute of Technology, 77 Massachusetts Avenue, Room E25-342, Cambridge, MA 02139.

RNAi induces destruction of specific mRNA and can be used to hinder protein expression. Therapeutic delivery of RNAi to localized areas can be achieved through liposomal encapsulation. RNAi encapsulating liposomes were prepared and observed to reduce GFP expression from genetically-modified, GFP expressing HeLa cells. In addition, polymer protected liposomes were prepared to reduce immune recognition. These polymers are released upon the pH change from the bloodstream (pH 7.4) and the endosome (pH 5-6). Polymer protected liposomes show increased cell viability and enhanced performance.