Browsing by Author "Moarefian, Maryam"

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    Development of Microfluidic Platforms for Electric Field-Driven Drug Delivery and Cell Migration
    Moarefian, Maryam (Virginia Tech, 2020-06-02)
    Recent technologies in micro-devices for investigation of functional biology in a controlled microenvironment are continually growing and evolving. In particular, electric-field mediated microfluidic platforms are evolving technologies that have significant applications in drug delivery and cell migration investigations. Although drug delivery has had several successes, in some areas, it continues to be a challenge; in recent years, the positive impact of electric fields is being explored. The primary objectives of the dissertation are to design, fabricate, and employ two novel microfluidic platforms for drug delivery and cell migration in the presence of electric fields. Description of iontophoretic carboplatin delivery into the MDA-MB-231 triple-negative breast cancer cells and investigation of neutrophil electro taxis are two main aims of the dissertation. Transdermal drug delivery systems such as iontophoresis are useful tools for delivering chemotherapeutics for tumor treatment not only because of their non-invasiveness but also due to their lower systematic toxicity compared to other drug delivery systems. While iontophoresis animal models are commonly being used for the development of new cancer therapies, there are some obstacles for precise control of the tumor microenvironment's chemoresistance and scaffold in the animal models. We employed experimental and computational approaches, the iontophoresis-on-chip and the fraction of tumor killed mathematical model, for predicting the outcome of iontophoresis treatment in a controlled microenvironment. Also, precise control over the cell electromigration is a challenging investigation which we will address in the second aim of the dissertation. Here, we developed a microfluidic platform to study the consequences of DC electric fields on neutrophil electromigration (electrotaxis), which has an application of directing neutrophils away from healthy tissue by suppressing the migration of neutrophils toward pro-inflammatory chemoattractant.
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    Electrotaxis-on-Chip to Quantify Neutrophil Migration Towards Electrochemical Gradients
    Moarefian, Maryam; Davalos, Rafael V.; Burton, Michael D.; Jones, Caroline N. (2021-08-06)
    Electric fields are generated in vivo in a variety of physiologic and pathologic settings, including wound healing and immune response to injuries to epithelial barriers (e.g. lung pneumocytes). Immune cells are known to migrate towards both chemical (chemotaxis), physical (mechanotaxis) and electric stimuli (electrotaxis). Electrotaxis is the guided migration of cells along electric fields, and has previously been reported in T-cells and cancer cells. However, there remains a need for engineering tools with high spatial and temporal resolution to quantify EF guided migration. Here we report the development of an electrotaxis-on-chip (ETOC) platform that enables the quantification of dHL-60 cell, a model neutrophil-like cell line, migration toward both electrical and chemoattractant gradients. Neutrophils are the most abundant white blood cells and set the stage for the magnitude of the immune response. Therefore, developing engineering tools to direct neutrophil migration patterns has applications in both infectious disease and inflammatory disorders. The ETOC developed in this study has embedded electrodes and four migration zones connected to a central cell-loading chamber with migration channels [10 mu m X 10 mu m]. This device enables both parallel and competing chemoattractant and electric fields. We use our novel ETOC platform to investigate dHL-60 cell migration in three biologically relevant conditions: 1) in a DC electric field; 2) parallel chemical gradient and electric fields; and 3) perpendicular chemical gradient and electric field. In this study we used differentiated leukemia cancer cells (dHL60 cells), an accepted model for human peripheral blood neutrophils. We first quantified effects of electric field intensities (0.4V/cm-1V/cm) on dHL-60 cell electrotaxis. Our results show optimal migration at 0.6 V/cm. In the second scenario, we tested whether it was possible to increase dHL-60 cell migration to a bacterial signal [N-formylated peptides (fMLP)] by adding a parallel electric field. Our results show that there was significant increase (6-fold increase) in dHL60 migration toward fMLP and cathode of DC electric field (0.6V/cm, n=4, p-value<0.005) vs. fMLP alone. Finally, we evaluated whether we could decrease or re-direct dHL-60 cell migration away from an inflammatory signal [leukotriene B-4 (LTB4)]. The perpendicular electric field significantly decreased migration (2.9-fold decrease) of dHL60s toward LTB4 vs. LTB4 alone. Our microfluidic device enabled us to quantify single-cell electrotaxis velocity (7.9 mu m/min +/- 3.6). The magnitude and direction of the electric field can be more precisely and quickly changed than most other guidance cues such as chemical cues in clinical investigation. A better understanding of EF guided cell migration will enable the development of new EF-based treatments to precisely direct immune cell migration for wound care, infection, and other inflammatory disorders.
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    Heparin-based hydrogel scaffolding alters the transcriptomic profile and increases the chemoresistance of MDA-MB-231 triple-negative breast cancer cells
    Menon, Nidhi; Dang, Ha X.; Datla, Udaya Sree; Moarefian, Maryam; Lawrence, Christopher B.; Maher, Christopher A.; Jones, Caroline N. (2020-05-21)
    The tumor microenvironment plays a critical role in the proliferation and chemoresistance of cancer cells. Growth factors (GFs) are known to interact with the extracellular matrix (ECM) via heparin binding sites, and these associations influence cell behavior. In the present study, we demonstrate the ability to define signals presented by the scaffold by pre-mixing growth factors, such as epidermal growth factor, into the heparin-based (HP-B) hydrogel prior to gelation. In the 3D biomimetic microenvironment, breast cancer cells formed spheroids within 24 hours of initial seeding. Despite higher number of proliferating cells in 2D cultures, 3D spheroids exhibited a higher degree of chemoresistance after 72 hours. Further, our RNA sequencing results highlighted the phenotypic changes influenced by solid-phase GF presentation. Wnt/beta-catenin and TGF-beta signaling were upregulated in the cells grown in the hydrogel, while apoptosis, IL2-STAT5 and PI3K-AKT-mTOR signaling were downregulated. With emerging technologies for precision medicine in cancer, this nature of fine-tuning the microenvironment is paramount for cultivation and downstream characterization of primary cancer cells and rare circulating tumor cells (CTCs), and effective screening of chemotherapeutic agents.
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    Modeling iontophoretic drug delivery in a microfluidic device
    Moarefian, Maryam; Davalos, Rafael V.; Tafti, Danesh K.; Achenie, Luke E. K.; Jones, Caroline N. (2020-09-21)
    Iontophoresis employs low-intensity electrical voltage and continuous constant current to direct a charged drug into a tissue. Iontophoretic drug delivery has recently been used as a novel method for cancer treatment in vivo. There is an urgent need to precisely model the low-intensity electric fields in cell culture systems to optimize iontophoretic drug delivery to tumors. Here, we present an iontophoresis-on-chip (IOC) platform to precisely quantify carboplatin drug delivery and its corresponding anti-cancer efficacy under various voltages and currents. In this study, we use an in vitro heparin-based hydrogel microfluidic device to model the movement of a charged drug across an extracellular matrix (ECM) and in MDA-MB231 triple-negative breast cancer (TNBC) cells. Transport of the drug through the hydrogel was modeled based on diffusion and electrophoresis of charged drug molecules in the direction of an oppositely charged electrode. The drug concentration in the tumor extracellular matrix was computed using finite element modeling of transient drug transport in the heparin-based hydrogel. The model predictions were then validated using the IOC platform by comparing the predicted concentration of a fluorescent cationic dye (Alexa Fluor 594 (R)) to the actual concentration in the microfluidic device. Alexa Fluor 594 (R) was used because it has a molecular weight close to paclitaxel, the gold standard drug for treating TNBC, and carboplatin. Our results demonstrated that a 50 mV DC electric field and a 3 mA electrical current significantly increased drug delivery and tumor cell death by 48.12% +/- 14.33 and 39.13% +/- 12.86, respectively (n = 3, p-value <0.05). The IOC platform and mathematical drug delivery model of iontophoresis are promising tools for precise delivery of chemotherapeutic drugs into solid tumors. Further improvements to the IOC platform can be made by adding a layer of epidermal cells to model the skin.
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    Quaternary Ammonium Compound Disinfectants Reduce Lupus-Associated Splenomegaly by Targeting Neutrophil Migration and T-Cell Fate
    Abdelhamid, Leila; Cabana-Puig, Xavier; Mu, Qinghui; Moarefian, Maryam; Swartwout, Brianna K.; Eden, Kristin; Das, Prerna; Seguin, Ryan P.; Xu, Libin; Lowen, Sarah; Lavani, Mital; Hrubec, Terry C.; Jones, Caroline N.; Luo, Xin M. (2020-10-21)
    Hypersensitivity reactions and immune dysregulation have been reported with the use of quaternary ammonium compound disinfectants (QACs). We hypothesized that QAC exposure would exacerbate autoimmunity associated with systemic lupus erythematosus (lupus). Surprisingly, however, we found that compared to QAC-free mice, ambient exposure of lupus-prone mice to QACs led to smaller spleens with no change in circulating autoantibodies or the severity of glomerulonephritis. This suggests that QACs may have immunosuppressive effects on lupus. Using a microfluidic device, we showed that ambient exposure to QACs reduced directional migration of bone marrow-derived neutrophils toward an inflammatory chemoattractant ex vivo. Consistent with this, we found decreased infiltration of neutrophils into the spleen. While bone marrow-derived neutrophils appeared to exhibit a pro-inflammatory profile, upregulated expression of PD-L1 was observed on neutrophils that infiltrated the spleen, which in turn interacted with PD-1 on T cells and modulated their fate. Specifically, QAC exposure hindered activation of splenic T cells and increased apoptosis of effector T-cell populations. Collectively, these results suggest that ambient QAC exposure decreases lupus-associated splenomegaly likely through neutrophil-mediated toning of T-cell activation and/or apoptosis. However, our findings also indicate that even ambient exposure could alter immune cell phenotypes, functions, and their fate. Further investigations on how QACs affect immunity under steady-state conditions are warranted.