Conventional electroporation approaches show limitations in the delivery of macromolecules in vitro and in vivo.These limitations include low efficiency,noticeable cell damage and nonuniform delivery of cells.Here,we ...Conventional electroporation approaches show limitations in the delivery of macromolecules in vitro and in vivo.These limitations include low efficiency,noticeable cell damage and nonuniform delivery of cells.Here,we present a simple 3D electroporation platform that enables massively parallel single-cell manipulation and the intracellular delivery of macromolecules and small molecules.A pyramid pit micropore array chip was fabricated based on a silicon wet-etching method.A controllable vacuum system was adopted to trap a single cell on each micropore.Using this chip,safe single-cell electroporation was performed at low voltage.Cargoes of various sizes ranging from oligonucleotides(molecular beacons,22 bp)to plasmid DNA(CRISPR-Cas9 expression vectors,>9 kb)were delivered into targeted cells with a significantly higher transfection efficiency than that of multiple benchmark methods(e.g.,commercial electroporation devices and Lipofectamine).The delivered dose of the chemotherapeutic drug could be controlled by adjusting the applied voltage.By using CRISPR-Cas9 transfection with this system,the p62 gene and CXCR7 gene were knocked out in tumor cells,which effectively inhibited their cellular activity.Overall,this vacuum-assisted micropore array platform provides a simple,efficient,high-throughput intracellular delivery method that may facilitate on-chip cell manipulation,intracellular investigation and cancer therapy.展开更多
This paper outlines the design of a novel mode-localized electric current sensor based on a mechanically sensitive element of weakly coupled resonator systems.With the advantage of a high voltage sensitivity of weakly...This paper outlines the design of a novel mode-localized electric current sensor based on a mechanically sensitive element of weakly coupled resonator systems.With the advantage of a high voltage sensitivity of weakly coupled resonator systems,the current under test is converted to voltage via a silicon shunt resistor,which causes stiffness perturbation to one resonator.The mode-localization phenomenon alters the energy distribution in the weakly coupled resonator system.A theoretical model of current sensing is established,and the performance of the current sensor is determined:the sensitivity of the electric current sensor is 567/A,the noise floor is 69.3 nAA/Hz,the resolution is 183.6 nA,and the bias instability is 81.6 nA.The mode-localized electric current sensor provides a new approach for measuring sub-microampere currents for applications in nuclear physics,including for photocurrent signals and transistor leakage currents.It could also become a key component of a portable mode-localized multimeter when combined with a mode-localized voltmeter.In addition,it has the potential for use in studying sensor arrays to achieve higher resolution.展开更多
基金L.C.acknowledges the funding from INSCA at the Beijing Advanced Innovation Center for Biomedical Engineering and Beihang Universitystart-up funding was received from UNT.
文摘Conventional electroporation approaches show limitations in the delivery of macromolecules in vitro and in vivo.These limitations include low efficiency,noticeable cell damage and nonuniform delivery of cells.Here,we present a simple 3D electroporation platform that enables massively parallel single-cell manipulation and the intracellular delivery of macromolecules and small molecules.A pyramid pit micropore array chip was fabricated based on a silicon wet-etching method.A controllable vacuum system was adopted to trap a single cell on each micropore.Using this chip,safe single-cell electroporation was performed at low voltage.Cargoes of various sizes ranging from oligonucleotides(molecular beacons,22 bp)to plasmid DNA(CRISPR-Cas9 expression vectors,>9 kb)were delivered into targeted cells with a significantly higher transfection efficiency than that of multiple benchmark methods(e.g.,commercial electroporation devices and Lipofectamine).The delivered dose of the chemotherapeutic drug could be controlled by adjusting the applied voltage.By using CRISPR-Cas9 transfection with this system,the p62 gene and CXCR7 gene were knocked out in tumor cells,which effectively inhibited their cellular activity.Overall,this vacuum-assisted micropore array platform provides a simple,efficient,high-throughput intracellular delivery method that may facilitate on-chip cell manipulation,intracellular investigation and cancer therapy.
基金supported by the National Key Research and Development Program of China(Grant No.2018YFB2002600)Fundamental Research Funds for the Central Universities(Grant No.3102019JC002).
文摘This paper outlines the design of a novel mode-localized electric current sensor based on a mechanically sensitive element of weakly coupled resonator systems.With the advantage of a high voltage sensitivity of weakly coupled resonator systems,the current under test is converted to voltage via a silicon shunt resistor,which causes stiffness perturbation to one resonator.The mode-localization phenomenon alters the energy distribution in the weakly coupled resonator system.A theoretical model of current sensing is established,and the performance of the current sensor is determined:the sensitivity of the electric current sensor is 567/A,the noise floor is 69.3 nAA/Hz,the resolution is 183.6 nA,and the bias instability is 81.6 nA.The mode-localized electric current sensor provides a new approach for measuring sub-microampere currents for applications in nuclear physics,including for photocurrent signals and transistor leakage currents.It could also become a key component of a portable mode-localized multimeter when combined with a mode-localized voltmeter.In addition,it has the potential for use in studying sensor arrays to achieve higher resolution.
