Nanoparticle Induced Cell Magneto-Rotation: Monitoring Morphology, Stress and Drug Sensitivity of a Suspended Single Cancer Cell

Single cell analysis has allowed critical discoveries in drug testing, immunobiology and stem cell research. In addition, a change from two to three dimensional growth conditions radically affects cell behavior. This already resulted in new observations on gene expression and communication networks and in better predictions of cell responses to their environment. However, it is still difficult to study the size and shape of single cells that are freely suspended, where morphological changes are highly significant. Described here is a new method for quantitative real time monitoring of cell size and morphology, on single live suspended cancer cells, unconfined in three dimensions. The precision is comparable to that of the best optical microscopes, but, in contrast, there is no need for confining the cell to the imaging plane. The here first introduced cell magnetorotation (CM) method is made possible by nanoparticle induced cell magnetization. By using a rotating magnetic field, the magnetically labeled cell is actively rotated, and the rotational period is measured in real-time. A change in morphology induces a change in the rotational period of the suspended cell (e.g. when the cell gets bigger it rotates slower). The ability to monitor, in real time, cell swelling or death, at the single cell level, is demonstrated. This method could thus be used for multiplexed real time single cell morphology analysis, with implications for drug testing, drug discovery, genomics and three-dimensional culturing

Recent developments on ZnO films for acoustic wave based bio-sensing and microfluidic applications: a review

Recent developments on the preparation and application of ZnO films for acoustic wave-based microfluidics and biosensors are reviewed in this paper. High quality and strongly textured ZnO thin films can be prepared using many technologies, among which RF magnetron sputtering is most commonly used. This paper reviews the deposition of ZnO film and summarizes the factors influencing the microstructure, texture and piezoelectric properties of deposited ZnO films. ZnO acoustic wave devices can be successfully used as biosensors, based on the biomolecule recognition using highly sensitive shear horizontal and Love-wave surface acoustic waves, as well as film bulk acoustic resonator devices. The acoustic wave generated on the ZnO acoustic devices can induce significant acoustic streaming, small scale fluid mixing, pumping, ejection and atomization, depending on the wave mode, amplitude and surface condition. The potential to fabricate an integrated lab-on-a-chip diagnostic system based on these ZnO acoustic wave technologies is also discussed