A Magnetically and Electrically Powered Hybrid Micromotor in Conductive Solutions: Synergistic Propulsion Effects and Label-Free Cargo Transport and Sensing

TL;DR

This paper introduces a hybrid micromotor combining magnetic and electric propulsion to enable label-free cargo transport and sensing of biological cells in conductive solutions, advancing single-cell analysis and drug delivery techniques.

Contribution

It demonstrates a novel hybrid propulsion method that extends electric micromotor capabilities to higher conductivity solutions, enabling label-free cell manipulation and analysis.

Findings

Enhanced micromotor mobility with combined magnetic and electric fields

Successful identification of apoptotic cells via dielectrophoretic differences

Effective trapping and transport of live cells with drug-loaded liposomes

Abstract

Electrically powered micro- and nanomotors are promising tools for in-vitro single-cell analysis. In particular, single cells can be trapped, transported and electroporated by a Janus particle (JP) using an externally applied electric field. However, while dielectrophoretic (DEP)-based cargo manipulation can be achieved at high-solution conductivity, electrical propulsion of these micromotors becomes ineffective at solution conductivities exceeding 0.3mS/cm. Here, we successfully extended JP cargo manipulation and transport capabilities to conductive near-physiological (<6mS/cm) solutions by combining magnetic field-based micromotor propulsion and navigation with DEP-based manipulation of various synthetic and biological cargos. Combination of a rotating magnetic field and electric field resulted in enhanced micromotor mobility and steering control through tuning of the electric field frequency. conditions are necessary. In addition, we demonstrated the micromotors ability of identifying apoptotic cell among viable and necrotic cells based their dielectrophoretic difference, thus, enabling to analyze the apoptotic status in the single cell samples for drug discovery, cell therapeutics and immunotherapy. We also demonstrated the ability to trap and transport live cells towards regions containing doxorubicin-loaded liposomes. This hybrid micromotor approach for label-free trapping, transporting and sensing of selected cells within conductive solutions, opens new opportunities in drug delivery and single cell analysis, where close-to-physiological media