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Author: Hebenstreit, Franziska × Author: Karnaushenko, Dmitriy D. × Author: Medina-Sánchez, Mariana × Author: Schmidt, Oliver G. × End date: 2024 × Start date: 2020 ×

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    Impedimetric Microfluidic Sensor-in-a-Tube for Label-Free Immune Cell Analysis
    (Weinheim : Wiley-VCH, 2021) Egunov, Aleksandr I.; Dou, Zehua; Karnaushenko, Dmitriy D.; Hebenstreit, Franziska; Kretschmann, Nicole; Akgün, Katja; Ziemssen, Tjalf; Karnaushenko, Daniil; Medina-Sánchez, Mariana; Schmidt, Oliver G.
    Analytical platforms based on impedance spectroscopy are promising for non-invasive and label-free analysis of single cells as well as of their extracellular matrix, being essential to understand cell function in the presence of certain diseases. Here, an innovative rolled-up impedimetric microfulidic sensor, called sensor-in-a-tube, is introduced for the simultaneous analysis of single human monocytes CD14+ and their extracellular medium upon liposaccharides (LPS)-mediated activation. In particular, rolled-up platinum microelectrodes are integrated within for the static and dynamic (in-flow) detection of cells and their surrounding medium (containing expressed cytokines) over an excitation frequency range from 102 to 5 × 106 Hz. The correspondence between cell activation stages and the electrical properties of the cell surrounding medium have been detected by electrical impedance spectroscopy in dynamic mode without employing electrode surface functionalization or labeling. The designed sensor-in-a-tube platform is shown as a sensitive and reliable tool for precise single cell analysis toward immune-deficient diseases diagnosis.
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    A Rotating Spiral Micromotor for Noninvasive Zygote Transfer
    (Hoboke, NJ : Wiley, 2020) Schwarz, Lukas; Karnaushenko, Dmitriy D.; Hebenstreit, Franziska; Naumann, Ronald; Schmidt, Oliver G.; Medina-Sánchez, Mariana
    Embryo transfer (ET) is a decisive step in the in vitro fertilization process. In most cases, the embryo is transferred to the uterus after several days of in vitro culture. Although studies have identified the beneficial effects of ET on proper embryo development in the earlier stages, this strategy is compromised by the necessity to transfer early embryos (zygotes) back to the fallopian tube instead of the uterus, which requires a more invasive, laparoscopic procedure, termed zygote intrafallopian transfer (ZIFT). Magnetic micromotors offer the possibility to mitigate such surgical interventions, as they have the potential to transport and deliver cellular cargo such as zygotes through the uterus and fallopian tube noninvasively, actuated by an externally applied rotating magnetic field. This study presents the capture, transport, and release of bovine and murine zygotes using two types of magnetic micropropellers, helix and spiral. Although helices represent an established micromotor architecture, spirals surpass them in terms of motion performance and with their ability to reliably capture and secure the cargo during both motion and transfer between different environments. Herein, this is demonstrated with murine oocytes/zygotes as the cargo; this is the first step toward the application of noninvasive, magnetic micromotor‐assisted ZIFT.