RNA circular single-stranded and method to produce

circular single stranded an RNA having an effect of RNA interference sustained or slow release, wherein the circular single-stranded RNA comprises a sequence of sense strand a secuenciade antisense complementary to the sequence of sense strand, two sequences identical loop odiferentes between the sense strand and the antisense strand, connecting both strands, wherein the chain consent and the antisense strand are paired to form a stem, and wherein each of the two sequences bucletiene 6 to 9 nucleotides in length .