Disclosed are particles which are introduced into target cells and suppress the expression of specific genes, and a method of manufacturing such particles. More particularly, the present invention relates to DNA-RNA hybrid particles that comprise a DNA strand and an RNA strand that binds to the DNA strand through partial complementary base pairing, in which the DNA strand comprises an aptamer sequence that is able to bind to a target protein produced in a target cell, and the RNA strand comprises an siRNA sequence that binds to a target RNA in the target cell to suppress protein expression from the target RNA. Such hybrid particles are capable of effectively delivering an siRNA therapeutic agent into target cells for the treatment of disease, and have resistance against digestion by in vivo nucleases, DNase and RNase, owing to complementary binding formed between DNA and RNA strands. Also, the present invention relates to a method of manufacturing such DNA-RNA hybrid particles.