纽约大学Nadrian C. Seeman教授为首的科学家们于20世纪90年代发展的DNA（脱氧核糖核酸）纳米自组装技术及其应用是近年来备受关注的纳米高技术领域，DNA纳米技术利用DNA分子的Watson和Crick碱基配对原则构建可操控的纳米结构或器件，并应用于药物递送、生物传感、纳米机器、和合成生物学等。DNA纳米技术近20年的发展都使用线性DNA为基本原料，线性DNA的 5’-和3’-两端在组装DNA阵列的过程中可自由转动和调整。环状DNA的超螺旋与解旋状态的相互转换是生命过程中常见和重要的分子运动，环状DNA没有自由的端头，碱基配对过程中转动和自我调节的自由度受限，但小环DNA（20至200个碱基）双链结构的刚性增加，我们将采用小环DNA设计和构建新的结构基元（motifs）和组装0、1、2、3维纳米结构，并籍此研究小环DNA的拓扑学性质和柔韧性，希冀为揭示生命的奥秘提供新视野。

Prof. Nadrian C. Seeman and his colleagues at New York University have developed the DNA self-assembly nanotechnology, using DNA molecules to construct DNA nanostructures and nanodevices, since the 1990’s of the 20th century. DNA nanostructures and nanodevices made by Watson and Crick base pairing can be applied in drug delivery, biosensing, nanorobots, and synthetic biology, etc. Over 20 years, linear DNA strands are the main raw materials used in DNA nanotechnology because both 5’- and 3’-ends of them can rotate and self-regulate freely to fit to the DNA lattice during the self-assembly process. Supercoiling and unwinding of circular DNA molecules, so called DNA topo-isomerization, is one of pivotal molecular motions in life science. Circular DNA molecules have no free-moving ends and their rotation and self-regulation are limited during base pairing. However small circular double helix DNA molecules are predicted to be more rigid, and they can be used to form new motifs and to construct new 0, 1, 2, and 3-dimensional DNA nanostructures and nanodevices. In addition the conformation, topology, and rigidity of small circular DNA molecules will be investigated from these nanostructures. Such DNA minicircle-based nanoarchitecture might provide a new vision to probe the mystery of life.