Aptamer-Modified Au Nanoparticles: Functional Nanozyme Bioreactors for Cascaded Catalysis and Catalysts for Chemodynamic Treatment of Cancer Cells

Citations Over TimeTop 10% of 2022 papers

Abstract

Polyadenine-stabilized Au nanoparticles (pA-AuNPs) reveal dual nanozyme catalytic activities toward the H₂O₂-mediated oxidation of dopamine to aminochrome and toward the aerobic oxidation of glucose to gluconic acid and H₂O₂. The conjugation of a dopamine-binding aptamer (DBA) to the pA-AuNPs yields aptananozyme structures catalyzing simultaneously the H₂O₂-mediated oxidation of dopamine to aminochrome through the aerobic oxidation of glucose. A set of aptananozymes consisting of DBA conjugated through the 5'- or 3'-end directly or spacer bridges to pA-AuNPs were synthesized. The set of aptananozymes revealed enhanced catalytic activities toward the H₂O₂-catalyzed oxidation of dopamine to dopachrome, as compared to the separated pA-AuNPs and DBA constituents, and structure-function relationships within the series of aptananozymes were demonstrated. The enhanced catalytic function of the aptananozymes was attributed to the concentration of the dopamine at the catalytic interfaces by means of aptamer-dopamine complexes. The dual catalytic activities of aptananozymes were further applied to design bioreactors catalyzing the effective aerobic oxidation of dopamine in the presence of glucose. Mechanistic studies demonstrated that the aptananozymes generate reactive oxygen species. Accordingly, the AS1411 aptamer, recognizing the nucleolin receptor associated with cancer cells, was conjugated to the pA-AuNPs, yielding a nanozyme for the chemodynamic treatment of cancer cells. The AS1411 aptamer targets the aptananozyme to the cancer cells and facilitates the selective permeation of the nanozyme into the cells. Selective cytotoxicity toward MDA-MB-231 breast cancer cells (ca. 70% cell death) as compared to MCF-10A epithelial cells (ca. 2% cell death) is demonstrated.

Related Papers

• → Aptamer cocktails: Enhancement of sensing signals compared to single use of aptamers for detection of bacteria(2013)87 cited
• → An aptamer cocktail-based electrochemical aptasensor for direct capture and rapid detection of tetracycline in honey(2019)40 cited
• → Idiosyncrasies of Thermofluorimetric Aptamer Binding Assays(2019)10 cited
• → Selecting DNA aptamers for endotoxin separation(2015)5 cited
• → Aptameric sensors based on structural change for diagnosis(2010)9 cited