Nucleic Acid Modification And Application Based On Click Chemistry

For a long time,people are very interested in the development of new synthetic methods for the construction of chemically modified DNA oligonucleotides,and it is expected that the related biological and nanotechnology applications will be developed based on the new synthetic methods.With the development of click chemistry,researchers quickly realized that the application of click chemistry in the field of nucleic acid research is limitless.The most common Copper-Catalyzed Azide-Alkyne Cycloaddition in click chemistry is one of the typical examples.The core groups,azide and alkyne groups,can be directly modified onto nucleic acids while retaining their biological and physical properties to the greatest extent.Moreover,the azide group and the unactivated alkynyl group are almost completely unreactive towards various common functional groups in nature,and the two groups only react with each other.In addition,the triazole groups generated by the reaction are extremely stable and have no obvious chemical toxicity.Based on the Copper-Catalyzed Azide-Alkyne Cycloaddition,we have designed alkynyl-modified oligonucleotides with different sequences to react with corresponding azide-containing chemical small molecules to obtain modified nucleic acid with different functions.On the one hand,we have modified the small molecule with the function of regulating G-quadruplex onto an oligonucleotide that is complementary to the downstream sequence of the G-rich sequence so that the small molecule can reach the G-rich region through the base-complementation between the oligonucleotides.In the G-rich region,the small molecule can regulate the structure of G-quadruplex.On the other hand,we modified the cyclodextrin onto the aptamer so that the drug-loaded cyclodextrin could use the cancer cell targeting function of the aptamer to reach the cancer cell.