为了加强反义核酸的细胞通透性、稳定性和特异性 ,对天然寡聚核苷酸进行修饰已成为其成功应用的基础。针对核酸的结构 ,修饰工作可以从其骨架、核糖和碱基入手 ,也可在核酸片段的末端进行偶联修饰。经过化学修饰后的反义核酸已被广泛地用于基础研究和药物开发 ,其中甲基化和硫代化的反义核酸药物已进入了临床试验。 In order to enhance cell permeability, stability and specificity of antisense nucleic acids, modification of natural oligonucleotides has become the basis for their successful application. For the structure of the nucleic acid, the modification can be started from its skeleton, ribose and base, and also can be modified at the end of the nucleic acid fragment. Chemically modified antisense nucleic acids have been widely used in basic research and drug development, in which methylated and thiolated antisense nucleic acid drugs have entered clinical trials.