A Smart mRNA-Initiated Theranostic Multi-shRNA Nanofactory for Precise and Efficient Cancer Gene Therapy.

Despite the significant potential of short hairpin RNA (shRNA)-mediated gene therapy for various diseases, the clinical success of cancer treatment remains poor, partly because of low selectivity and low efficiency. In this study, an mRNA-initiated autonomous multi-shRNA nanofactory (RNF@CM) is designed for in vivo amplification imaging and precise cancer treatment. The RNF@CM consists of a gold nanoparticle core, an interlayer of two types of three-stranded DNA/RNA hybrid probes, one of which is bound to aptamer-inhibited DNA polymerases, and an outer layer of the cancer cell membrane. After the specific delivery of RNF@CM into target cancer cells, an intracellular tumour-related mRNA target can initiate the RNF@CM with a circular strand-displacement polymerisation reaction, resulting in the release of significantly amplified fluorescence and continuous production of three types of shRNAs. The RNF@CM effectively distinguished cancer cells from normal cells, exclusively produced multiple shRNAs in response to a specific mRNA target in cancer cells, accurately diagnosed tumours in vivo, and significantly inhibited tumour growth with negligible toxicity, expanding the toolbox for on-demand gene delivery and precision theranostics.