US Patent 9950001 Polynucleotides having bioreversible groups

The disclosure provides methods and compositions for delivering polynucleotides into cells. The disclosure provides transiently protected polynucleotides comprising an anionic charge-neutralizing moiety/group, which may also confer additional functionality. These compounds can enter the cytosol of cells by endocytic or macropinocytic mechanisms. The transient protecting group is bioreversible, i.e., once inside a cell, it is designed to be removed by enzymatic activity or by passive intracellular methods (e.g., changes in pH or reductive environment).