Cellular Droplet Sorting and Manipulation for Immunity Analysis via Acoustofluidics

Abstract

Droplet microfluidics technology holds immense potential for single-cell level biomedical engineering studies, motivating the study of cellular immunotherapy, cell interactions, drug screening, and single-cell dynamics. However, existing droplet microfluidics have limited pairing efficiency, complex manual operation procedures, and low in-droplet cell manipulation capacity, which hinder their potential application in single-cell analyses with high sample purity or uniformity requirements. Several efforts, such as electrophoretic, magnetic, and optical droplet sorters, have been used to overcome some limitations. Still, they need the all-powerful capability of acoustics to solve all the problems. As a dynamic, precise, contact-free, and biocompatible force, acoustics can improve pairing efficiency in droplets and provide an ideal tool for active droplet manipulation. In this dissertation, I demonstrate the reinvention of droplet microfluidics, reporting the multifunctionality of acoustics for high throughput, high-precision droplet sorting, and active droplet manipulation. I propose a modular acoustofluidics platform designed for the streamlined sorting and collection of effector-target (i.e., NK92-K562) cell pairs, facilitating efficient monitoring of the real-time dynamics of immunological response formation. Coupled with transcriptional and protein expression analyses, I evaluated the synergistic effect of doxorubicin on the cellular immune response. In addition, because of the non-contact nature of acoustics, I can actively and simultaneously manipulate multiple cell-encapsulated droplets, which other methods cannot achieve. The proposed acoustofluidic platform can provide promising building blocks for high-throughput quantitative single-cell level coculture to understand intercellular communication while empowering immunotherapy through precision manipulation and analysis of immunological synapses.