Browsing by Author "Souza, Glauco R."

Now showing 1 - 6 of 6
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    A high-throughput three-dimensional cell migration assay for toxicity screening with mobile device-based macroscopic image analysis
    (Nature Publishing Group, 2013) Timm, David M.; Chen, Jianbo; Sing, David; Gage, Jacob A.; Haisler, William L.; Neeley, Shane K.; Raphael, Robert M.; Dehghani, Mehdi; Rosenblatt, Kevin P.; Killian, T.C.; Tseng, Hubert; Souza, Glauco R.
    There is a growing demand for in vitro assays for toxicity screening in three-dimensional (3D) environments. In this study, 3D cell culture using magnetic levitation was used to create an assay in which cells were patterned into 3D rings that close over time. The rate of closure was determined from time-lapse images taken with a mobile device and related to drug concentration. Rings of human embryonic kidney cells (HEK293) and tracheal smooth muscle cells (SMCs) were tested with ibuprofen and sodium dodecyl sulfate (SDS). Ring closure correlated with the viability and migration of cells in two dimensions (2D). Images taken using a mobile device were similar in analysis to images taken with a microscope. Ring closure may serve as a promising label-free and quantitative assay for high-throughput in vivo toxicity in 3D cultures.
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    A spheroid toxicity assay using magnetic 3D bioprinting and real-time mobile device-based imaging
    (Springer Nature, 2015) Tseng, Hubert; Gage, Jacob A.; Shen, Tsaiwei; Haisler, William L.; Neeley, Shane K.; Shiao, Sue; Chen, Jianbo; Desai, Pujan K.; Liao, Angela; Hebel, Chris; Raphael, Robert M.; Becker, Jeanne L.; Souza, Glauco R.
    An ongoing challenge in biomedical research is the search for simple, yet robust assays using 3D cell cultures for toxicity screening. This study addresses that challenge with a novel spheroid assay, wherein spheroids, formed by magnetic 3D bioprinting, contract immediately as cells rearrange and compact the spheroid in relation to viability and cytoskeletal organization. Thus, spheroid size can be used as a simple metric for toxicity. The goal of this study was to validate spheroid contraction as a cytotoxic endpoint using 3T3 fibroblasts in response to 5 toxic compounds (all-trans retinoic acid, dexamethasone, doxorubicin, 5′-fluorouracil, forskolin), sodium dodecyl sulfate (+control), and penicillin-G (−control). Real-time imaging was performed with a mobile device to increase throughput and efficiency. All compounds but penicillin-G significantly slowed contraction in a dose-dependent manner (Z’ = 0.88). Cells in 3D were more resistant to toxicity than cells in 2D, whose toxicity was measured by the MTT assay. Fluorescent staining and gene expression profiling of spheroids confirmed these findings. The results of this study validate spheroid contraction within this assay as an easy, biologically relevant endpoint for high-throughput compound screening in representative 3D environments.
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    Assembly of a Three-Dimensional Multitype Bronchiole Coculture Model Using Magnetic Levitation
    (Liebert, 2013) Tseng, Hubert; Gage, Jacob A.; Raphael, Robert M.; Moore, Robert H.; Killian, Thomas C.; Grande-Allen, K. Jane; Souza, Glauco R.
    A longstanding goal in biomedical research has been to create organotypic cocultures that faithfully represent native tissue environments. There is presently great interest in representative culture models of the lung, which is a particularly challenging tissue to recreate in vitro. This study used magnetic levitation in conjunction with magnetic nanoparticles as a means of creating an organized three-dimensional (3D) coculture of the bronchiole that sequentially layers cells in a manner similar to native tissue architecture. The 3D coculture model was assembled from four human cell types in the bronchiole: endothelial cells, smooth muscle cells (SMCs), fibroblasts, and epithelial cells (EpiCs). This study represents the first effort to combine these particular cell types into an organized bronchiole coculture. These cell layers were first cultured in 3D by magnetic levitation, and then manipulated into contact with a custom-made magnetic pen, and again cultured for 48 h. Hematoxylin and eosin staining of the resulting coculture showed four distinct layers within the 3D coculture. Immunohistochemistry confirmed the phenotype of each of the four cell types and showed organized extracellular matrix formation, particularly, with collagen type I. Positive stains for CD31, von Willebrand factor, smooth muscle a-actin, vimentin, and fibronectin demonstrate the maintenance of the phenotype for endothelial cells, SMCs, and fibroblasts. Positive stains for mucin-5AC, cytokeratin, and E-cadherin after 7 days with and without 1% fetal bovine serum showed that EpiCs maintained the phenotype and function. This study validates magnetic levitation as a method for the rapid creation of organized 3D cocultures that maintain the phenotype and induce extracellular matrix formation.
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    Systems and methods for magnetic guidance and patterning of materials
    (2014-08-26) Souza, Glauco R.; Pasqualini, Renata; Arap, Wadih; Killian, Thomas Charles; Raphael, Robert M.; Stark, Daniel Joshua; Rice University; Board of Regents of the University of Texas System; United States Patent and Trademark Office
    Systems and methods generally useful in medicine, cellular biology, nanotechnology, and cell culturing are discussed. In particular, at least in some embodiments, systems and methods for magnetic guidance and patterning of cells and materials are discussed. Some specific applications of these systems and methods may include levitated culturing of cells away from a surface, making and manipulating patterns of levitated cells, and patterning culturing of cells on a surface. Specifically, a method of culturing cells is presented. The method may comprise providing a plurality of cells, providing a magnetic field, and levitating at least some of the plurality of cells in the magnetic field, wherein the plurality of cells comprise magnetic nanoparticles. The method may also comprise maintaining the levitation for a time sufficient to permit cell growth to form an assembly.
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    Systems and methods for magnetic guidance and patterning of materials
    (2020-11-24) Souza, Glauco R.; Pasqualini, Renata; Arap, Wadih; Killian, Thomas Charles; Raphael, Robert M.; Stark, Daniel Joshua; Rice University; The Board of Regents of the University of Texas System; United States Patent and Trademark Office
    Systems and methods generally useful in medicine, cellular biology, nanotechnology, and cell culturing are discussed. In particular, at least in some embodiments, systems and methods for magnetic guidance and patterning of cells and materials are discussed. Some specific applications of these systems and methods may include levitated culturing of cells away from a surface, making and manipulating patterns of levitated cells, and patterning culturing of cells on a surface. Specifically, a method of culturing cells is presented. The method may comprise providing a plurality of cells, providing a magnetic field, and levitating at least some of the plurality of cells in the magnetic field, wherein the plurality of cells comprise magnetic nanoparticles. The method may also comprise maintaining the levitation for a time sufficient to permit cell growth to form an assembly.
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    Systems and methods for magnetic guidance and patterning of materials
    (2018-03-06) Souza, Glauco R.; Pasqualini, Renata; Arap, Wadih; Killian, Thomas Charles; Raphael, Robert M.; Stark, Daniel Joshua; Rice University; United States Patent and Trademark Office
    Systems and methods generally useful in medicine, cellular biology, nanotechnology, and cell culturing are discussed. In particular, at least in some embodiments, systems and methods for magnetic guidance and patterning of cells and materials are discussed. Some specific applications of these systems and methods may include levitated culturing of cells away from a surface, making and manipulating patterns of levitated cells, and patterning culturing of cells on a surface. Specifically, a method of culturing cells is presented. The method may comprise providing a plurality of cells, providing a magnetic field, and levitating at least some of the plurality of cells in the magnetic field, wherein the plurality of cells comprise magnetic nanoparticles. The method may also comprise maintaining the levitation for a time sufficient to permit cell growth to form an assembly.