TiO2∼Deoxyribozyme Nanocomposites as Delivery System and Efficient Site-Specific Agents for Cleavage of RNA Targets

Synthetic DNA molecules of 10-23 deoxyribozymes (Dz) are known to be efficient and site-specific agents for the RNA cleavage in a catalytic manner. To provide the penetration of Dz into cells, we have proposed the new delivery system for deoxyribozymes in the form of TiO2•PL-Dz nanocomposite. These nanocomposites consist of catalytically active Dz molecules noncovalently immobilized through the polylysine linker to TiO2 nanoparticles, which provide the penetration of Dz into cells. Deoxyribozymes in the prepared TiO2•PL-Dz nanocomposites were shown to retain their ability to cleave RNA targets albeit at a slower rate but with the same site-specificity and similar efficiency as free Dz. Unlike free Dz, the proposed TiO2•PL-Dz nanocomposites penetrate into cells without auxiliary actions.