Antimicrobial framework nucleic acid-based DNAzyme cluster with high catalytic efficiency

BACKGROUND: Hydroxyl radical-mediated materials primarily liberate more reactive and acutely lethal hydroxyl radical (^•OH) and act as potent bactericidal antibiotics, for example H₂O₂. Hydroxyl radical possess higher tendency than that of H₂O₂ to attack various biological molecules such as DNA, proteins and iron–sulfur clusters, and impair their proper functioning, actively leading to strongly potent bactericidal effect. To acquire the desired antimicrobial effect, high concentration of H₂O₂ is required that has found medically harmful to healthy tissues of humans. RESULTS: We herein report framework nucleic acid-regulated DNAzyme cluster (FDC) – that is, peroxidase-like hemin-bound G-quadruplex (G4/H) DNAzyme – to amplify the catalytic reduction potential of G4/H complex, leading to high conversion rate of H₂O₂ to more reactive hydroxyl radical that potentially shows the same antibacterial efficiency at lower and safer H₂O₂ concentration. Specifically, we have grafted multiple copies of DNAzymes outside framework nucleic acid (FNA) to successively achieve 3–9 orders of magnitude enhancement in catalytic activity and antibacterial efficiency of FDC. CONCLUSION: Our designed FDC has successfully alleviated H₂O₂ toxicity and increased its efficiency as antibacterial material, as FDC amplified the catalytic reduction potential of G4/H DNAzyme, leading to high conversion rate of H₂O₂ to more reactive ^•OH that potentially shows the same antibacterial efficiency at lower and safer H₂O₂ concentration.