(courtesy: Cao Research Group, UF)

A nanozyme is a gold nanoparticle combined with an endonuclease and DNA complementary to a specific target RNA sequence. When DNA-RNA recognition occurs, the endonuclease cleaves the target RNA site-specifically. Nanozyme is a promising alternative to RNA interference (RNAi) agents for controlling gene expression by cutting RNA selectively in cells, according to researchers at the University of Florida. They designed nanozymes to mimic RNA-induced silencing complexes (RISCs). The working components of RNAi, RISCs use strands from small interfering RNAs (siRNAs) and endonucleases to cleave RNA in cells.
Nanozymes are gold nanoparticles decorated both with DNA sequences and endoribonucleases. The DNA sequences act like siRNA strands in that they complement the target RNAs and the nanozyme endoribonucleases, like RISC endoribonucleases, are capable of cleaving those target RNAs.
Applications
Nanozymes are nanoparticle-based conjugates having several capabilities. Nanozymes represent an innovative new approach for gene silencing in cells and in vivo. They can be used to cleave viral RNA and suppress viral replication in cultured cells. They also readily enter cultured virus-infected human liver cells and cleave HCV RNA, reducing viral protein expression and subduing viral replication without causing any obvious toxicity to the cells. Nanozymes can also add targeting moieties to nanoparticle conjugates to provide greater selectivity for specific tissues such as tumors or specific organs such as liver.
The nanozyme can solve the difficulties associated with the use of siRNA-based drugs. The nanozymes are more stable, longer lasting, and less toxic than RNAi agents and may have potential as therapeutics for diseases that can be treated by controlling gene expression. 

It is being evaluated as to how nanozymes respond to DNA/target-RNA mismatches and assessed for their ability to induce a range of different cytokines. According to researchers nanozyme platform allows them to add functionality that could direct nanozymes to specific tissues, organs, and even sub cellular organelles that express target genes.