Optically computed phase microscopy for quantitative dynamic imaging of label-free cells and nanoparticles.

Numerous drug delivery systems based on nanoparticles have been developed, such as those used in BioNTech/Pfizer's and Moderna's Covid vaccines. Knowledge on mechanical interactions between cells and nanoparticles is critical to advance the efficiency and safety of these drug delivery systems. To quantitatively track the motion of cell (transparent) and nanoparticles (nontransparent) with nanometer displacement sensitivity, we investigate a novel imaging technology, optically computed phase microscopy (OCPM) that processes 3D spatial-spectral data through optical computation. We demonstrate that OCPM has the capability to image the motion of cells and magnetic nanoparticles that are mechanically excited by an external magnetic field, quantitatively and in the en face plane.