UC Irvine

The immunological network comprises of complex and interconnected system of cells, tissues and molecules that work together to defend the body against foreign invaders, such as bacteria, viruses, and cancer cells. This network includes different types of immune cells, such as T cells, B cells, natural killer cells, and dendritic cells, as well as various molecules, such as cytokines, chemokines, and antibodies. The immunological network functions through series of interactions and feedback loops, in which different components of the immune systems communicate with each other to coordinate their activities and mount an effective immune response. In my Ph.D. dissertation, I will be focusing on three essential components for therapeutic discovery and development: T cells, cancer cells, and antibodies. These three components initiate reciprocal communications and coordinate with each other within the human body to maintain homeostasis. However, genetic mutation or uncooperative behavior in their relationships can lead to the initiation of cancer. To better understand and defend against cancer, it’s crucial to detect the disease, develop targeted cell therapies and screen drugs effectively. Three specific platforms that aid in these efforts have been developed. The first is a 3D confinement enabled system that activates and expands human primary T cells. The second is a rapid acoustic microstreaming platform to isolate tumor cells from patient blood samples, aiding in the diagnosis of cancer. The third platform is an acoustic microstreaming platform that screens antibody/drug viscosity. Autologous cell therapy depends on T lymphocyte expansion efficiency and is hindered by suboptimal interactions between T cell receptors and peptide-MHC molecules. Various artificial antigen presenting cell systems that enhance these interactions are often labor-intensive, fabrication costly, highly variable, and potentially unscalable towards clinical setting. Here, 3D confinement-enabled priming of T cell immune-synapse junctions was performed to generate tight T cell–Dynabead skeletons at a rate 200-fold faster than that of conventional 24-h bulk shaking. Furthermore, by forming T cell–Dynabead skeletons in the starting culture, two- to six-fold greater T cell expansion was achieved over conventional T cell expansion for cancer patient-derived primary T cells, and excessive cell exhaustion was not induced. Creating 3D T cell–Dynabead skeletons as the “booster” material enables highly efficient polyclonal T cell expansion without the need for complex surface modification of artificial antigen-presenting cells. This method can be modularly adapted to existing T cell expansion processes for various applications, including adoptive cell therapies (ACTs). The second platform is based on an acoustic microstreaming microfluidic platform. We demonstrate a label free and high-throughput microbubble-based acoustic microstreaming technique to isolate rare circulating cells such as circulating cancer associated fibroblasts (cCAFs) in addition to circulating tumor cells (CTCs) and immune cells (i.e. leukocytes) from clinically diagnosed patients with a capture efficiency of 94% while preserving cell functional integrity within 8 minutes. The microfluidic device is self-pumping and was optimized to increase flow rate and achieve near perfect capturing of rare cells enabled by having a trapping capacity above the acoustic vortex saturation concentration threshold. Our approach enables rapid isolation of CTCs, cCAFs and their associated clusters from blood samples of cancer patients at different stages. By examining the combined role of cCAFs and CTCs in early cancer onset and metastasis progression, the device accurately diagnoses both cancer and the metastatic propensity of breast cancer patients. Our LCAT-based approach can thus be developed into a metastatic propensity assay for clinical usage by elucidating cancer immunological responses and the complex relationships between CTCs and its companion tumor microenvironment. Lastly, we demonstrate an acoustic microstreaming platform termed as microfluidic viscometer by acoustic streaming transducers (µVAST) that induces fluid transport from second-order microstreaming to measure viscosity. Measurement of fluid viscosity represents a huge need for many biomedical and materials processing applications. Sample fluids containing DNA, antibodies, protein-based drugs, and even cells have become important therapeutic options. The physical properties, including viscosity, of these biologics are critical factors in the optimization of the biomanufacturing processes and delivery of therapeutics to patients. Validation of our platform is achieved with different glycerol content mixtures to reflect different viscosities and show that viscosity can be estimated based on the maximum speed of the second-order acoustic microstreaming. The µVAST platform requires only a small volume of fluid sample (~ 1.2 uL), which is 16 – 30 times smaller than that of commercial viscometers. In addition, µVAST can be scaled up for ultra-high throughput measurements of viscosity. Here we demonstrate 16 samples within 3 seconds, which is an attractive feature for automating the process flows in drug development and materials manufacturing and production.