Dynamic pH-responsive DNA cube nanopores for adaptive transmembrane transport

Developing lipid vesicles capable of self-regulation to adapt dynamically to environmental changes remains a significant challenge. In this study, we introduce a pH-responsive DNA-based transmembrane channel (p-cube) integrated into lipid vesicles, enabling adaptive environmental responses. This nanopore, comprising four DNA strands, is anchored within lipid membranes via cholesterol modifications, with two semi-i-motif sequences strategically positioned at the apex. The i-motif structure exhibits pH-dependent folding behavior, allowing the DNA cube to reversibly open or close the nanopore in response to ambient pH variations. Fluorescence kinetic experiments demonstrated efficient, reversible modulation of transmembrane transport triggered by pH fluctuations. Furthermore, the capability of autonomous regulation under non-equilibrium conditions was validated by encapsulating glucose oxidase within vesicles and externally supplying glucose. The resulting proton generation from glucose oxidation induced pH-driven structural switching of the DNA nanopores, demonstrating environmental sensing and adaptive behavior reminiscent of natural cellular membranes. This intelligent and responsive transmembrane system holds significant potential for applications in targeted drug delivery, biosensing, and synthetic biology, providing novel approaches for precise environmental responsiveness and dynamic signaling regulation.