Nucleic Acid Drugs and DNA-based Delivery Systems.

Nucleic acids are biologically active materials, and chemically modified nucleic acids are now being used in nucleic acid drugs. DNA, one of the two types of nucleic acids, can also be used as a material to construct DNA-based delivery systems, such as DNA hydrogel, for therapeutic compounds. Use of chemically modified nucleic acids would greatly increase the therapeutic potency of such DNA-based delivery systems. However, attention should be paid to the differences in the physicochemical properties of natural and chemically modified nucleic acids. Another, more important concern for chemically modified nucleic acids is the high cost of their synthesis. Reducing the cost of synthesizing oligonucleotides, and especially ones with chemically modified nucleic acids, is crucial to the expanded use of both nucleic acid drugs and DNA-based delivery systems.