Thomas Zangle

University of Utah | UOU · Department of Chemical Engineering

Microfluidic devices are widely used for biomedical applications based on microscopy or other optical detection methods. However, the materials commonly used for microfabrication typically have a high refractive index relative to water, which can create artifacts at device edges and limit applicability to applications requiring high-precision imagi...

Significance This study addresses why splenic B lymphocytes show differential cell proliferation and death decisions, and whether these may be predictable. Biology provides examples of both stochastic decision making and highly deterministic developmental programs. Prior studies of B lymphocytes suggested these cells make stochastic decisions, but...

Somatic cell reprogramming to pluripotency requires an immediate increase in cell proliferation and reduction in cell size. It is unknown whether proliferation and biomass controls are similarly coordinated with early events during the differentiation of pluripotent stem cells (PSCs). This impasse exists because PSCs grow in tight clusters or colon...

Current methods of optimizing electroosmotic (EO) pump performance include reducing pore diameter and reducing ionic strength of the pumped electrolyte. However, these approaches each increase the fraction of total ionic current carried by diffuse electric double layer (EDL) counterions. When this fraction becomes significant, concentration polariz...

In this tutorial review aimed at researchers using nanofluidic devices, we summarize the current state of theoretical and experimental approaches to describing concentration polarization (CP) in hybrid microfluidic-nanofluidic systems. We also analyze experimental results for these systems and place them in the context of recent theoretical develop...

Background Acral melanoma (AM) is an aggressive melanoma variant that arises from palmar, plantar, and nail unit melanocytes. Compared to non-acral cutaneous melanoma (CM), AM is biologically distinct, has an equal incidence across genetic ancestries, typically presents in advanced stage disease, is less responsive to therapy, and has an overall wo...

Significance Imaging changes in subcellular structure is critical to understanding cell behavior but labeling can be impractical for some specimens and may induce artifacts. Although darkfield microscopy can reveal internal cell structures, it often produces strong signals at cell edges that obscure intracellular details. By optically eliminating t...

Transport within cells is commonly studied using particle tracking methods. However, these typically require either labeling or identification of specific organelles that can be identified and tracked from label-free imaging modalities, limiting application of this approach. Quantitative phase imaging (QPI) provides dynamic data on the redistributi...

How do cancer cells grow, divide, proliferate, and die? How do drugs infuence these processes? These are diffcult questions that we can attempt to answer with a combination of time-series microscopy experiments, classifcation algorithms, and data visualization. However, collecting this type of data and applying algorithms to segment and track cells...

This work combines refractive-index-matched microwells with quantitative phase imaging to track the lineage and mass of single founder cells.

Significance Measuring changes in cellular structure and organelles is crucial for understanding disease progression and cellular responses to treatments. A label-free imaging method can aid in advancing biomedical research and therapeutic strategies. Aim This study introduces a computational darkfield imaging approach named quadrant darkfield (QD...

The continuous balance of growth and degradation inside cells maintains homeostasis. Disturbance of this balance by internal or external factors cause state of disease, while effective disease treatments seek to restore this balance. Here, we present a method based on quantitative phase imaging (QPI) based measurements of cell mass and the velocity...

How do cancer cells grow, divide, proliferate and die? How do drugs influence these processes? These are difficult questions that we can attempt to answer with a combination of time-series microscopy experiments, classification algorithms, and data visualization. However, collecting this type of data and applying algorithms to segment and track cel...

Measurements of cell lineages is central to a variety of fundamental biological questions, ranging from developmental to cancer biology. However, accurate lineage tracing requires nearly perfect cell tracking, which can be challenging due to cell motion during imaging. Here we demonstrate the integration of microfabrication, imaging, and image proc...

The continuous balance of growth and degradation inside cells maintains homeostasis. Disturbance of the balance by internal or external factors cause state of disease. Effective disease treatments seek to restore this balance. Here, we present a method based on quantitative phase imaging (QPI) based measurements of cell mass and the velocity of mas...

Epithelial cells work collectively to provide a protective barrier, yet also turn over rapidly by cell death and division. If the number of dying cells does not match those dividing, the barrier would vanish, or tumors can form. Mechanical forces and the stretch-activated ion channel (SAC) Piezo1 link both processes; stretch promotes cell division...

Recent studies reveal that lateral mitochondrial transfer, the movement of mitochondria from one cell to another, can affect cellular and tissue homeostasis1,2. Most of what we know about mitochondrial transfer stems from bulk cell studies and have led to the paradigm that functional transferred mitochondria restore bioenergetics and revitalize cel...

The combination of multiple imaging modalities in a single microscopy system can enable new insights into biological processes. In this work, we describe the construction and rigorous characterization of a custom microscope with multimodal imaging in a single, cost-effective system. Our design utilizes advances in LED technology, robotics, and open...

Quantitative phase imaging (QPI) measures the growth rate of individual cells by quantifying changes in mass versus time. Here, we use the breast cancer cell lines MCF-7, BT-474, and MDA-MB-231 to validate QPI as a multiparametric approach for determining response to single-agent therapies. Our method allows for rapid determination of drug sensitiv...

Quantitative phase imaging (QPI) is a label-free, wide-field microscopy approach with significant opportunities for biomedical applications. QPI uses the natural phase shift of light as it passes through a transparent object, such as a mammalian cell, to quantify biomass distribution and spatial and temporal changes in biomass. Reported in cell stu...

Transport of mass within cells helps maintain homeostasis and is disrupted by disease and stress. Here, we develop quantitative phase velocimetry (QPV) as a label-free approach to make the invisible flow of mass within cells visible and quantifiable. We benchmark our approach against alternative image registration methods, a theoretical error model...

Quantitative phase imaging (QPI) measures the growth rate of individual cells by quantifying changes in mass versus time. Here, we use the breast cancer cell lines MCF-7, BT-474, and MDA-MB-231 to validate QPI as a multiparametric approach for determining response to single-agent therapies. Our method allows for rapid determination of drug sensitiv...

Which drug is most promising for a cancer patient? A new microscopy-based approach for measuring the mass of individual cancer cells treated with different drugs promises to answer this question in only a few hours. However, the analysis pipeline for extracting data from these images is still far from complete automation: human intervention is nece...

Lateral transfer of mitochondria occurs in many physiological and pathological conditions. Given that mitochondria provide essential energy for cellular activities, mitochondrial transfer is currently thought to promote the rescue of damaged cells. We report that mitochondrial transfer occurs between macrophages and breast cancer cells, leading to...

Transport of mass within cells helps maintain homeostasis and is disrupted by disease and stress. Here, we develop quantitative phase velocimetry (QPV) as a label-free approach to make the invisible flow of mass within cells visible and quantifiable. We benchmark our approach against alternative image registration methods, a theoretical error model...

Introduction: The ability for oncologists to predict a cancer's response to therapy is limited to a few biomarkers used for histologic diagnosis and targeted therapy. Often, in advanced and metastatic disease these biomarkers provide no alternative options for next step systemic treatments. There is a need in oncology for functional assays that can...

Which drug is most promising for a cancer patient? This is a question a new microscopy-based approach for measuring the mass of individual cancer cells treated with different drugs promises to answer in only a few hours. However, the analysis pipeline for extracting data from these images is still far from complete automation: human intervention is...

The optical properties of polymer materials used for microfluidic device fabrication can impact device performance when used for optical measurements. In particular, conventional polymer materials used for microfluidic devices have a large difference in refractive index relative to aqueous media generally used for biomedical applications. This can...

Measurement of neuron behavior is crucial for studying neural development and evaluating the impact of potential therapies on neural regeneration. Conventional approaches to imaging neuronal behavior require labeling and do not separately quantify the growth processes that underlie neural regeneration. In this paper we demonstrate the use of quanti...

The viscoelastic properties of mammalian cells can vary with biological state, such as during the epithelial-to-mesenchymal (EMT) transition in cancer, and therefore may serve as a useful physical biomarker. To characterize stiffness, conventional techniques use cell contact or invasive probes and as a result are low throughput, labor intensive, an...

Cell cycle deregulation is a cancer hallmark that has stimulated the development of mitotic inhibitors with differing mechanisms of action. Quantitative phase imaging (QPI) is an emerging approach for determining cancer cell sensitivities to chemotherapies in vitro. Cancer cell fates in response to mitotic inhibitors are agent- and dose-dependent....

Abstract Ampk is an energy gatekeeper that responds to decreases in ATP by inhibiting energy-consuming anabolic processes and promoting energy-generating catabolic processes. Recently, we showed that Lkb1, an understudied kinase in B lymphocytes and a major upstream kinase for Ampk, had critical and unexpected roles in activating naïve B cells and...

The use of microfluidic devices has emerged as a defining tool for biomedical applications. When combined with modern microscopy techniques, these devices can be implemented as part of a robust platform capable of making simultaneous complementary measurements. The primary challenge created by the combination of these two techniques is the mismatch...

We report the development of High Speed Live Cell Interferometry (HSLCI), a new multi-sample, multi-drug testing platform for directly measuring tumor therapy response via real-time optical cell biomass measurements. As a proof-of-concept, we show that HSLCI rapidly profiles changes in biomass in BRAF inhibitor (BRAFi) sensitive, parental melanoma...

Standard algorithms for phase unwrapping often fail for interferometric quantitative phase imaging (QPI) of biological samples due to the variable morphology of these samples and the requirement to image at low light intensities to avoid phototoxicity. We describe a new algorithm combining random walk-based image segmentation with linear discrimina...

The equal partitioning of cell mass between daughters is the usual and expected outcome of cytokinesis for self-renewing cells. However, most studies of partitioning during cell division have focused on daughter cell shape symmetry or segregation of chromosomes. Here, we use live cell interferometry (LCI) to quantify the partitioning of daughter ce...

Cell mass, volume and growth rate are tightly controlled biophysical parameters in cellular development and homeostasis, and pathological cell growth defines cancer in metazoans. The first measurements of cell mass were made in the 1950s, but only recently have advances in computer science and microfabrication spurred the rapid development of preci...

Cancer cell proliferation relies on the ability of cancer cells to grow, transition through the cell cycle, and divide. To identify novel chemical probes for dissecting the mechanisms governing cell cycle progression and cell division, and for developing new anti-cancer therapeutics, we developed and performed a novel cancer cell-based high-through...

Adoptive immunotherapies against cancer, in which cytotoxic, CD8+ T cells engineered to express T cell receptors (TCRs) targeting cancer-associated antigens are transplanted into a patient, have shown dramatic promise in clinical trials. A major impediment to the widespread use of this technique for treatment of diverse cancers is the lack of a fas...

Existing approaches that quantify cytotoxic T cell responses rely on bulk or surrogate measurements which impede the direct identification of single activated T cells of interest. Single cell microscopy or flow cytometry methodologies typically rely on fluorescent labeling, which limits applicability to primary cells such as human derived T lymphoc...

Intensity images of cells on the interferometer stage after 18 h of imaging showing typical target cell conditons. Left column shows the full image frame, the right column shows a subset of the full image frame. (A)–(D) M202 target cells plated with F5 TCR transduced, CD8+ T cells showing nearly complete death of target cells. For comparison, (A) a...

Four panel video showing intensity images, mass distribution images, and mass vs. time of a target M202 cell being killed by a cytotoxic T cell (CD8+, F5 TCR transduced) over the course of 5 hours of observation by LCI. (MOV)

Averaged, normalized mass versus time plots for control target cell growth conditions showing robust growth on the LCI stage, and specificity of T cell mediated cytotoxicity. (A) Unaffected M202 cells (n = 632) during treatment with F5 TCR transduced, CD8+ T cells. (B) M202 cells (n = 117) prior to treatment with F5 TCR transduced, CD8+ T cells. (C...

(A)–(J). Mass versus time plots for CTLs and corresponding target cells, as in Figure 4A. t = 0 h is the point at which the target cell detaches from the substrate at the beginning of cell death. CTL + target cell refers to total mass of both cells in frames where they could not be measured individually, typically due to overlap between the CTL and...

(A) Mass and (B) area histograms for activated and unresponsive T cells, relative to control experiments. Activated = activated/cytotoxic F5 TCR transduced T cells, 116 cells, n = 3 experiments. Unactivated = unactivated/unresponsive F5 TCR transduced T cells, 359 cells, n = 3 experiments. F5neg = untransduced F5 TCR negative T cells plated with M2...

Averaged, normalized mass versus time for unresponsive T cells showing steady growth on the LCI stage. (A) Unresponsive F5 TCR transduced CD8+ T cells (n = 101) plated with M202 target cells. (B) Untransduced CD8+ T cells (n = 146) plated with M202 target cells. (C) F5 TCR transduced CD8+ T cells (n = 950) plated with antigen-irrelevant, PC-3 prost...

Despite the potential high impact of human pluripotent stem cell (hPSC) research in developmental biology, cancer biology, and regenerative medicine, surprisingly little is known about how hPSCs grow, divide, and respond to their environment. In this talk, we will introduce live cell interferometery (LCI) as a new, biophysical measurement approach...

Live cell mass profiling is a promising new approach for rapidly quantifying responses to therapeutic agents through picogram-scale changes in cell mass over time. A significant barrier in mass profiling is the inability of existing methods to handle pleomorphic cellular clusters and clumps, which are more commonly present in patient-derived sample...

Despite much attention to the regulation of genetic material partitioning during cell division, relatively little is known about the partitioning of cell mass, an essential outcome of successful cytokinesis. Recent work suggests that mispartitioning of cellular contents during division may constitute a form of epigenetic memory, however, convention...

Live Cell Interferometry (LCI) is a real time imaging technology that is extremely well suited to capture motion on the micro- and even nano-scale, with a temporal dynamic range and field of view that far exceeds scanning probe techniques. We will describe the development and application of LCI for rapid, real-time quantification of single-cell mas...

A central question in cancer therapy is how individual cells within a population of tumor cells respond to drugs designed to arrest their growth. However, the absolute growth of cells, their change in physical mass, whether cancerous or physiologic, is difficult to measure directly with traditional techniques. Here, we develop live cell interferome...

We extend the analytical theory of propagating concentration polarization (CP) to describe and compare the effects of constant-voltage versus constant-current conditions on the transient development of CP enrichment and depletion zones. We support our analysis with computational and experimental results. We find that at constant voltage, enrichment...

Porous structures with submicron pore diameters and low ionic strength electrolytes yield more efficient electroosmotic (EO) pumps. For these conditions, however, electric double layers may carry a substantial portion of ionic current, creating an imbalance between current carried by anions versus cations. This leads to the formation of net neutral...

Electroosmotic (EO) pumps can generate relatively high pressure and flow rate using no moving parts and small package volumes. Pumps with one micron (and smaller) pore diameters are promising for applications requiring high flow rate per power, such as drug delivery systems. We here show that such EO pumps exhibit significant concentration polariza...

We develop two models to describe ion transport in variable-height micro- and nanochannels. For the first model, we obtain a one-dimensional (unsteady) partial differential equation governing flow and charge transport through a shallow and wide electrokinetic channel. In this model, the effects of electric double layer (EDL) on axial transport are...

We present results of a combined computational and experimental study of the propagation of concentration polarization (CP) zones in a microchannel-nanochannel system. Our computational model considers the combined effects of bulk flow, electromigration, and diffusion and accurately captures the dynamics of CP. Using wall charge inside the nanochan...

Nanopores offer the potential for label-free analysis of individual proteins and low cost DNA sequencing. In order to design and evaluate nanopore devices, an understanding of nanopore electrokinetic transport is crucial. However, most studies of nanopore electrokinetic transport have neglected the effects of concentration polarization (CP) in the...

Recent advances in fabrication methods allow us to study and leverage the unique flow regimes offered by nano-scale fluidic channels, [1–3] and recent work suggests that the physics of microchannel/nanochannel interfaces present opportunities for novel methods of sample preconcentration and analysis. [4–6] In nanochannels, channel height is of the...