skip to main content


Title: Pumpless, unidirectional microphysiological system for testing metabolism‐dependent chemotherapeutic toxicity
Abstract

Drug development is often hindered by the failure of preclinical models to accurately assess and predict the efficacy and safety of drug candidates. Body‐on‐a‐chip (BOC) microfluidic devices, a subset of microphysiological systems (MPS), are being created to better predict human responses to drugs. Each BOC is designed with separate organ chambers interconnected with microfluidic channels mimicking blood recirculation. Here, we describe the design of the first pumpless, unidirectional, multiorgan system and apply this design concept for testing anticancer drug treatments. HCT‐116 colon cancer spheroids, HepG2/C3A hepatocytes, and HL‐60 promyeloblasts were embedded in collagen hydrogels and cultured within compartments representing “colon tumor”, “liver,” and “bone marrow” tissue, respectively. Operating on a pumpless platform, the microfluidic channel design provides unidirectional perfusion at physiologically realistic ratios to multiple channels simultaneously. The metabolism‐dependent toxic effect of Tegafur, an oral prodrug of 5‐fluorouracil, combined with uracil was examined in each cell type. Tegafur‐uracil treatment induced substantial cell death in HCT‐116 cells and this cytotoxic response was reduced for multicellular spheroids compared to single cells, likely due to diffusion‐limited drug penetration. Additionally, off‐target toxicity was detected by HL‐60 cells, which demonstrate that such systems can provide useful information on dose‐limiting side effects. Collectively, this microscale cell culture analog is a valuable physiologically‐based pharmacokinetic drug screening platform that may be used to support cancer drug development.

 
more » « less
NSF-PAR ID:
10452359
Author(s) / Creator(s):
 ;  ;  
Publisher / Repository:
Wiley Blackwell (John Wiley & Sons)
Date Published:
Journal Name:
Biotechnology Progress
Volume:
37
Issue:
2
ISSN:
8756-7938
Format(s):
Medium: X
Sponsoring Org:
National Science Foundation
More Like this
  1. null (Ed.)
    The burden of cancer continues to increase in society and negatively impacts the lives of numerous patients. Due to the high cost of current treatment strategies, there is a crucial unmet need to develop inexpensive preclinical platforms to accelerate the process of anti-cancer drug discovery to improve outcomes in cancer patients, most especially in female patients. Many current methods employ expensive animal models which not only present ethical concerns but also do not often accurately predict human physiology and the outcomes of anti-cancer drug responsiveness. Conventional treatment approaches for cancer generally include systemic therapy after a surgical procedure. Although this treatment technique is effective, the outcome is not always positive due to various complex factors such as intratumor heterogeneity and confounding factors within the tumor microenvironment (TME). Patients who develop metastatic disease still have poor prognosis. To that end, recent efforts have attempted to use 3D microengineered platforms to enhance the predictive power and efficacy of anti-cancer drug screening, ultimately to develop personalized therapies. Fascinating features of microengineered assays, such as microfluidics, have led to the advancement in the development of the tumor-on-chip technology platforms, which have shown tremendous potential for meaningful and physiologically relevant anti-cancer drug discovery and screening. Three dimensional microscale models provide unprecedented ability to unveil the biological complexities of cancer and shed light into the mechanism of anti-cancer drug resistance in a timely and resource efficient manner. In this review, we discuss recent advances in the development of microengineered tumor models for anti-cancer drug discovery and screening in female-related cancers. We specifically focus on female-related cancers to draw attention to the various approaches being taken to improve the survival rate of women diagnosed with cancers caused by sex disparities. We also briefly discuss other cancer types like colon adenocarcinomas and glioblastoma due to their high rate of occurrence in females, as well as the high likelihood of sex-biased mutations which complicate current treatment strategies for women. We highlight recent advances in the development of 3D microscale platforms including 3D tumor spheroids, microfluidic platforms as well as bioprinted models, and discuss how they have been utilized to address major challenges in the process of drug discovery, such as chemoresistance, intratumor heterogeneity, drug toxicity, etc. We also present the potential of these platform technologies for use in high-throughput drug screening approaches as a replacements of conventional assays. Within each section, we will provide our perspectives on advantages of the discussed platform technologies. 
    more » « less
  2. Three-dimensional (3D) tumor spheroid models have gained increased recognition as important tools in cancer research and anti-cancer drug development. However, currently available imaging approaches employed in high-throughput screening drug discovery platforms e.g. bright field, phase contrast, and fluorescence microscopies, are unable to resolve 3D structures deep inside (>50 μm) tumor spheroids. In this study, we established a label-free, non-invasive optical coherence tomography (OCT) imaging platform to characterize 3D morphological and physiological information of multicellular tumor spheroids (MCTS) growing from ~250 μm up to ~600 μm in height over 21 days. In particular, tumor spheroids of two cell lines glioblastoma (U-87 MG) and colorectal carcinoma (HCT 116) exhibited distinctive evolutions in their geometric shapes at late growth stages. Volumes of MCTS were accurately quantified using a voxel-based approach without presumptions of their geometries. In contrast, conventional diameter-based volume calculations assuming perfect spherical shape resulted in large quantification errors. Furthermore, we successfully detected necrotic regions within these tumor spheroids based on increased intrinsic optical attenuation, suggesting a promising alternative of label-free viability tests in tumor spheroids. Therefore, OCT can serve as a promising imaging modality to characterize morphological and physiological features of MCTS, showing great potential for high-throughput drug screening. 
    more » « less
  3. Abstract

    Measurement of cell metabolism in moderate-throughput to high-throughput organ-on-chip (OOC) systems would expand the range of data collected for studying drug effects or disease in physiologically relevant tissue models. However, current measurement approaches rely on fluorescent imaging or colorimetric assays that are focused on endpoints, require labels or added substrates, and lack real-time data. Here, we integrated optical-based oxygen sensors in a high-throughput OOC platform and developed an approach for monitoring cell metabolic activity in an array of membrane bilayer devices. Each membrane bilayer device supported a culture of human renal proximal tubule epithelial cells on a porous membrane suspended between two microchannels and exposed to controlled, unidirectional perfusion and physiologically relevant shear stress for several days. For the first time, we measured changes in oxygen in a membrane bilayer format and used a finite element analysis model to estimate cell oxygen consumption rates (OCRs), allowing comparison with OCRs from other cell culture systems. Finally, we demonstrated label-free detection of metabolic shifts in human renal proximal tubule cells following exposure to FCCP, a drug known for increasing cell oxygen consumption, as well as oligomycin and antimycin A, drugs known for decreasing cell oxygen consumption. The capability to measure cell OCRs and detect metabolic shifts in an array of membrane bilayer devices contained within an industry standard microtiter plate format will be valuable for analyzing flow-responsive and physiologically complex tissues during drug development and disease research.

     
    more » « less
  4. Abstract

    Microfluidic devices that combine an extracellular matrix environment, cells, and physiologically relevant perfusion, are advantageous as cell culture platforms. We developed a hydrogel-based, microfluidic cell culture platform by loading polyethylene glycol (PEG) hydrogel-encapsulated U87 glioblastoma cells into membrane-capped wells in polydimethyl siloxane (PDMS). The multilayer microfluidic cell culture system combines previously reported design features in a configuration that loads and biomimetically perfuses a 2D array of cell culture chambers. One dimension of the array is fed by a microfluidic concentration gradient generator (MCGG) while the orthogonal dimension provides loading channels that fill rows of cell culture chambers in a separate layer. In contrast to typical tree-like MCGG mixers, a fractional serial dilution of 1, ½, ¼, and 0 of the initial solute concentration is achieved by tailoring the input microchannel widths. Hydrogels are efficiently and reproducibly loaded in all wells and cells are evenly distributed throughout the hydrogel, maintaining > 90% viability for up to 4 days. In a drug screening assay, diffusion of temozolomide and carmustine to hydrogel-encapsulated U87 cells from the perfusion solution is measured, and dose–response curves are generated, demonstrating utility as an in vitro mimic of the glioblastoma microenvironment.

     
    more » « less
  5. Abstract

    Metastatic breast cancer is one of the deadliest forms of malignancy, primarily driven by its characteristic micro‐environment comprising cancer cells interacting with stromal components. These interactions induce genetic and metabolic alterations creating a conducive environment for tumor growth. In this study, a physiologically relevant 3D vascularized breast cancer micro‐environment is developed comprising of metastatic MDA‐MB‐231 cells and human umbilical vein endothelial cells loaded in human dermal fibroblasts laden fibrin, representing the tumor stroma. The matrix, as well as stromal cell density, impacts the transcriptional profile of genes involved in tumor angiogenesis and cancer invasion, which are hallmarks of cancer. Cancer‐specific canonical pathways and activated upstream regulators are also identified by the differential gene expression signatures of these composite cultures. Additionally, a tumor‐associated vascular bed of capillaries is established exhibiting dilated vessel diameters, representative of in vivo tumor physiology. Further, employing aspiration‐assisted bioprinting, cancer–endothelial crosstalk, in the form of collective angiogenesis of tumor spheroids bioprinted at close proximity, is identified. Overall, this bottom–up approach of tumor micro‐environment fabrication provides an insight into the potential of in vitro tumor models and enables the identification of novel therapeutic targets as a preclinical drug screening platform.

     
    more » « less