Cell Surface Engineering Using DNAzymes: Metal Ion Mediated Control of Cell-Cell Interactions.

Regulating cell-cell interactions and cell behaviors via cell surface engineering is of significance for biological research such as cell fate control and cell therapy. While extensive efforts have been made to induce cell-cell assembly via various cell surface modifications triggered by macromolecules or organic metabolites, controllable cell-cell interactions that include both assembly and disassembly triggered by metal ions remain a challenge. Herein, we report a strategy based on DNAzymes to realize controllable cell-cell interactions, triggered by metal ions. The metal-dependent DNAzyme-based cleavage can effectively manipulate cell behaviors, including cell-cell conjunctions and disaggregation. Using a Zn2+-specific DNAzyme, a Mg2+-specific DNAzyme, and their respective substrate strands as the building blocks, the corresponding DNA double-chain switches enabling two-factor disassembly are demonstrated. Moreover, the method has been applied to control the assembly and disassembly between two cell spheroids. Since a wide variety of metal-specific DNAzymes are available, this method can be readily applied to construct cell dynamic systems controlled by other metal ions, providing a smart and versatile platform to regulate dynamic cell behavior.