Rectifying artificial nanochannels with multiple interconvertible permeability states

Transmembrane channels play a vital role in regulating the permeation process, and have inspired recent development of biomimetic channels. Herein, we report a class of artificial biomimetic nanochannels based on DNAzyme-functionalized glass nanopipettes to realize delicate control of channel permeability, whereby the surface wettability and charge can be tuned by metal ions and DNAzyme-substrates, allowing reversible conversion between different permeability states. We demonstrate that the nanochannels can be reversibly switched between four different permeability states showing distinct permeability to various functional molecules. By embedding the artificial nanochannels into the plasma membrane of single living cells, we achieve selective transport of dye molecules across the cell membrane. Finally, we report on the advanced functions including gene silencing of miR-21 in single cancer cells and selective transport of Ca2+ into single PC-12 cells. In this work, we provide a versatile tool for the design of rectifying artificial nanochannels with on-demand functions.

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Ruo-Can Qian, Yi Yi Lu Lu Jan 22, 2024 The nanopipette was fixed under the microscope for electrochemical measurements by by a holder (Axon Instruments, Union City, CA).All ionic current recordings were carried out using an an Axopatch 200B low-noise amplifier and an an Axon Digidata 1550A low-noise data acquisition system (Molecular Devices, Sunnyvale, CA).Microscopic cell images were collected using IS-Elements BR BR 5.30.05 64.The Supplementary Movies were collected using oCam.All the FL FL images were obtained using a water dipping objective (60×) on on a laser scanning confocal microscope (Nikon A1R., Japan).All software used in in this study for data collection are either commercially available or or open source.
The ionic current data were carried out using Clampfit 10.6 and then plotted by by Origin ( 2021) and further imported to to Adobe Illustrator (2021).Numerical simulations of of the electro-osmotic flow inside the nanopipette were performed using COMSOL Multiphysics 5.4 (COMSOL AB, Stockholm, Sweden) to to show the detailed profiles of of the voltage and concentration distribution of of TB TB dyes.The 2D 2D axisymmetric model was designed for mimicking the cone-shaped nanopipettes based on on the electrostatics module and the creeping flow module, can be be found in in the Supplementary Information.All reported errors in in the manuscript and supplementary information represent one standard deviation.Statistical analyses were carried out using Excel (Microsoft Office 365) and Origin (2021).The figures were plotted by by Origin (2021) and further imported to to Adobe Illustrator (2021).

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Experiments were repeated three independently times.All attempts of replication were successful.
Cells were randomly allocated into control and experimental groups for cell injection.
Data collection and analysis were not blinded.Blinding was not relevant because the study is a pilot investigation.The main purpose of the study was to test the feasibility of DNAzyme-functionalized artificial biomimetic nanochannels to realize precise control of the inner surface wettability and charge between four different states under external stimuli.Blinding might complicate the experimental setup or workflow, potentially leading to inefficiencies in this pilot experiment.
We require information from authors about some types of materials, experimental systems and methods used in many studies.Here, indicate whether each material, system or method listed is relevant to your study.If you are not sure if a list item applies to your research, read the appropriate section before selecting a response.The main data supporting this study's results are avaiable within the paper and its Supplementary Information.Source data are provided with this paper.The raw data has been provided in source data and has been deposited in Figshare database at https://figshare.com/s/7f0e66ea96f7ac4f557a.Additional relevant information is available from the corresponding author.The sample analysis, at least 3 samples were tested for each state (state 1, state 2, state 3 and state 4).No statistical methods were used to determine sample size.The sample size were decided according to a previous study using the same cohorts of samples.The selection of the sample size took into account both statistical significance and the timeliness of validating experimental performance in exploratory experiments.