Locked Nucleic Acid-Modified Antisense miR-10b Oligonucleotides Form Stable Duplexes on Gold Nanoparticles

Abstract

The interaction of locked nucleic acid (LNA)-modified antisense miR-10b oligonucleotides and its complementary DNA (cDNA) analog is studied using gold nanoparticles. We demonstrate that LNA shows a slower hybridization rate with complementary DNA molecules, however improves the melting temperature (∼15 °C) and duplex stability significantly. The dramatic difference in melting temperatures between the LNA–cDNA and DNA–cDNA duplexes is examined through the change in aggregation of gold nanoparticles by monitoring the absorbance values at 525, 570, and 600 nm. Furthermore, the difference in melting temperatures enables us to control gold nanoparticle assembly/disassembly with free DNA/LNA oligonucleotides at various temperatures. This heat-induced rearrangement of gold nanoparticles and oligonucleotides is monitored by naked eye and UV–Vis spectroscopy. Owing to the remarkable duplex stability with complementary oligonucleotides, LNA not only plays an important role in medicine but also is a significant tool in biomaterials science.