Self-cleavage of genetically encoded Zn²⁺-dependent deoxyribozymes for low-cost biotechnological production of programable responsive DNA hydrogels

Despite the emergence of sequence-programable responsive DNA hydrogels, their further development is still hampered by the limited availability of chemically synthesized nucleic acid constituents. We herein developed a cost-efficient biotechnological approach for general production of programable responsive DNA hydrogels by harnessing bacteria as cell factories. Programmable pseudogenes of responsive DNA hydrogels were designed by interleaving Y-unit strand sequences with Zn²⁺-dependent self-cleaving deoxyribozymes. After in vivo amplification, self-cleavage of these deoxyribozymes in extracted precursor ssDNAs were systematically investigated. The versatility of this approach was demonstrated by preparing a unitary Y-unit system of pH-responsive DNA hydrogel and a binary Y-unit system of Cas12a-responsive hydrogel. This low-cost biotechnological approach requires only standard molecular biology equipment and inexpensive consumables, which may encourage further exploration of responsive DNA hydrogels.