Figure 8.

Intracellular assembly of NANPs can be designed on the basis of the Tornado system.²¹³ NANP building blocks transcribed from one or several vectors are flanked by ribozymes that, after self-cleavage, create termini—a 5′ hydroxyl and a 2′,3′-cyclic phosphate at the 3′ end that are recognized by endogenous RtcB ligase. The resulting circularized sequence is chemically stable and, in addition to the Broccoli aptamer, can also code for another functional aptamer (e.g., NF-κB). This system is inspiring for the creation of intracellular structures that can assemble into NANPs.