Patent ID: 8668933
Filing Date: 2014-03-11
Classification: A61P,C12N,Y10T

Abstract:
1. A polyion complex consisting of a double-stranded ribonucleic acid and a block copolymer of formula (I) or (II), which are electrostatically bound together, wherein the polyion complex has an average particle diameter of less than 50 nm as measured by a dynamic light scattering measuring method, and wherein the block copolymer and the double-stranded ribonucleic acid are present in a ratio of N/P=1.2 to 1.5, wherein N represents the total number of cations in the block copolymer, and P represents the total number of phosphoester bonds or equivalent bonds in the double-stranded ribonucleic acid: wherein each of R each of L R R each of R m represents an integer of 5 to 20000, n represents an integer of 2 to 5000, and x represents an integer of 1 to 5.