Dynamic Switchable and Transient DNA Condensates Driven by Aptamer‐Ligand or Ion‐Nucleobase Bridged Complexes

ABSTRACT Phase‐separated DNA‐based coacervates undergoing dynamic switchable or transient evolution and depletion are introduced. Y‐shaped DNA reaction modules crosslinked by palindromic strands conjugated to cooperatively stabilized metal‐ions/mismatched bridges, C‐Ag ⁺ ‐C or T‐Hg ²⁺ ‐T, evolved phase‐separated microdroplets. Removal of the bridging ions by cysteamine (MEA) for Ag ⁺ or dimercaptosuccinic acid (DMSA) for Hg ²⁺ separates the condensates. Cyclic treatment of Y‐shaped modules and the palindromic strands with Ag ⁺ /Hg ²⁺ , and the subsequent ligands MEA/DMSA, result switchable formation/dissociation of the condensates. In addition, crosslinking of Y‐shaped DNA reaction modules with palindromic strand, and cooperatively stabilized or destabilized by aptamer/ligand complexes, leads, in the presence of an auxiliary biocatalyst, separating the ligand/aptamer complexes, to the transient evolution/depletion of the condensates. This is exemplified with the adenosine‐induced phase‐separation of condensates by crosslinking of aptamer subunit‐modified Y‐shaped modules with palindromic strands cooperatively stabilized by adenosine/aptamer‐subunits. In the presence of adenosine deaminase (ADA), transforming adenosine to inosine, the transient, dissipative depletion of the condensates proceeds. Alternatively, crosslinking of DNA Y‐shaped modules with palindromic strands conjugated to adenosine aptamer units, leads to the evolution of phase‐separated adenosine‐responsive microdroplets. In the presence of adenosine and ADA, the transient depletion of the microdroplets and their dynamic temporal reassembly proceeds.