Logic-gated in situ assembly of membrane-anchored G-quadruplex potassium channels for cancer cell apoptosis

An ATP/pH AND DNA nanodevice in situ DNA channel assembly. • Fusogenic liposomes anchor the nanodevice to cancer cell membranes. • Logic activation yields a FRET signal for tumor-responsive imaging. • Assembled G-quadruplex channels on cell surface promote intracellular K + efflux and induces cell apoptosis. Background Precise recognition of the tumor microenvironment (TME) coupled with selective activation of therapeutic functions remains a major challenge in precision medicine. To address this, we present a fusogenic liposome-anchored DNA nanodevice that performs an AND logic operation in response to ATP and acidic pH and undergoes in situ assembly on the plasma membrane. Results The nanodevice comprises two transmembrane DNA strands (S1 and S2) containing pH-responsive i-motif switches and split G-quadruplex segments that are sequestered by ATP-binding aptamers. Upon fusion with the cell membrane, TME-specific stimuli trigger the structural reconfiguration of the nanodevice. Acidic conditions induce i-motif folding, bringing the two strands into proximity, while ATP binding displaces the aptamer locks. Under acidic and ATP-rich conditions, aptamer release and i-motif folding jointly promote membrane-localized assembly of a G-quadruplex structure. The nanodevice showed a ratiometric fluorescence response to pH and ATP, including a linear ATP response from 0.2 to 1.0 mM with a detection limit of 0.097 mM. The assembled G-quadruplex structure acted as an artificial transmembrane ion channel, induced intracellular K + depletion, mitochondrial membrane depolarization, caspase-3 activation, and apoptosis. Significance This work provides a proof-of-concept strategy for logic-gated ion interference under tumor-mimicking extracellular conditions, highlighting the utility of DNA nanodevices in translating multiple microenvironmental stimuli into targeted cellular perturbations. A fusogenic liposome-anchored DNA nanodevice was developed for the in situ assembly of artificial ion channels to drive tumor-specific potassium efflux and apoptosis. Download: Download high-res image (362KB) Download: Download full-size image