Microfluidics for studying metastatic patterns of lung cancer

Abstract

The incidence of lung cancer continues to rise worldwide. Because the aggressive metastasis of lung cancer cells is the major drawback of successful therapies, the crucial challenge of modern nanomedicine is to develop diagnostic tools to map the molecular mechanisms of metastasis in lung cancer patients. In recent years, microfluidic platforms have been given much attention as tools for novel point-of-care diagnostic, an important aspect being the reconstruction of the body organs and tissues mimicking the in vivo conditions in one simple microdevice. Herein, we present the first comprehensive overview of the microfluidic systems used as innovative tools in the studies of lung cancer metastasis including single cancer cell analysis, endothelial transmigration, distant niches migration and finally neoangiogenesis. The application of the microfluidic systems to study the intercellular crosstalk between lung cancer cells and surrounding tumor microenvironment and the connection with multiple molecular signals coming from the external cellular matrix are discussed. We also focus on recent breakthrough technologies regarding lab-on-chip devices that serve as tools for detecting circulating lung cancer cells. The superiority of microfluidic systems over traditional in vitro cell-based assays with regard to modern nanosafety studies and new cancer drug design and discovery is also addressed. Finally, the current progress and future challenges regarding printable and paper-based microfluidic devices for personalized nanomedicine are summarized.

Keywords: Lung cancer; Metastasis; Microfluidics; Nanomedicine; Nanosafety; Theranostics.

Fig. 1

Increased publication trend on microfluidics used in cancer studies in the years 2005–2018. Data were collected based on PUBMED and NCBI databases. The insert presents the estimated and expected worth of the microfluidic market in billion USD based on PR Newswire [33], Grand View Research [20], Markets and Markets [22] and Mordor Intelligence [34] estimations

Fig. 2

Microfluidic device for nanotoxicity testing originally designed in the GEMNS project (EuroNanoMed II program) by the Nanotoxicology group at the University of Bergen, Norway. Microfluidic set-up. A The microfluidic chip comprises four independent microfluidic channels (blue). Cells growing within the microfluidic channel are analyzed via cell-substrate electrical impedance using microelectrode arrays (gold) (scale bar, 5 mm). B Mounted microfluidic chip. On-chip liquid reservoirs (red dots), tubing from syringe pumps (red arrows), electrical contacts (yellow arrows) and tubing providing humidified air/CO₂ are connected to the chip

Fig. 3

Graphical representation of the microfluidic devices used in cancer studies described in the chapter 2. Presented microfluidic systems were applied to study the different stages of lung cancers metastasis. The figures are reproduced from Li et al. [8] with permission of Applied Biochemistry and Biotechnology, Kim et al. [13] and Xu et al. [72] with permission of Electrophoresis, Benoit et al. [73] with permission of Applied and Environmental Microbiology, Guo et al. [74] with permission of Biochemical and Biophysical Research Communications, Yu et al. [75] and Bai et al. [14] with permission of Oncotarget, Zhao et al. [47] with permission of Scientific Reports, Wang et al. [9] and Anguiano et al. [5] with permission of Plos One, Cui et al. [76] and Kao et al. [77] with permission of Biomicrofluidics, Zou et al. [78] with the permission of Analytical Chemistry, Tata et al. [38] with permission of Advances in Natural Sciences: Nanoscience and Nanotechnology, Huang et al. [39] and Li et al. [79] with permission of Biosensors and Bioelectronics, Li et al. [80] with the permission of Analytical and Bioanalytical Chemistry

Fig. 4

Impedance measurements of adenocarcinomic human alveolar basal epithelial cells (A549) in the microfluidic device originally designed in the “GEMNS” project (EuroNanoMed II program) by the Nanotoxicology group at the University of Bergen, Norway. Please see video information for A549 cells in the microfluidic device set-up (Additional file 1)

Fig. 5

On-chip biomimetic model to study metastatic lung cancer. Tumor microvasculature-on-a-chip. Top-view (top) and cross section (bottom) of a multicompartment microfluidic chip for the development of perfusable microvascular networks and microtumors. Diamond-like chambers support the growth of microvascular networks emended in extracellular matrix (ECM) gels, while flanking side channels are used to perfused nutrients and drugs. Perfusable microvascular networks are formed by co-culturing microvascular endothelial cells with lung fibroblast and vascular smooth muscle cells in the ECM gel. Lung cancer cells can be co-injected before ECM gelification to grow microtumors. Alternatively, lung cancer cells can be perfused via flanking channels to study metastatic colonization (adapted from Sobrino et al. [190])

Fig. 6

Static vs. dynamic conditions in cell-based assays for nanotoxicology. a Nanoparticles (NP)s tend to agglomerate and sediment in traditional cell-based assays performed under static conditions. This creates large particle agglomerates that are not readily taken up by cells. In addition, sedimentation generates concentration gradients. Therefore, delivered doses do not often match cellular doses (i.e., the amount of material in contact with and taken up by cells). b In contrast, cell-based assays performed in microfluidic devices, i.e., under dynamic conditions, allow perfusion of homogeneous NP dispersions from reservoirs equipped with mechanical stirrers. In addition, the fluid shear stress decreases NP agglomeration and sedimentation within the microfluidic channels. These two factors can be further reduced by designing microchannels structured with microgrooves and herringbone-microstructures to increase convective mixing

Fig. 7

Schematic diagram depicting the components of the microfluidic platform developed in the GEMNS project (EuroNanoMed II program) by the Nanotoxicology group, University of Bergen, Norway. In this setup, custom-made on-chip reservoirs are directly attached to the chip inlets and the fluid is withdrawn continuously through the outlets using pulsatile-free syringe pumps. The on-chip reservoirs are automatically refilled with homogeneous nanoparticle dispersions every 30 min using a programmable pressure pump. To ensure dispersion homogeneity, the liquid reservoir of the pressure pump is kept under agitation using a magnetic stirrer with a stirring bar that does not interact with nanoparticles. The microfluidic device consists of four independent microfluidic chambers, each with a microelectrode array to evaluate the cytotoxicity via a cell-substrate impedance sensing. Impedance measurements were performed sequentially using an electrode switch and a potentiostat

Fig. 8

Recent progress of microfluidic technologies in nanomedicine. The figures are reproduced from El-Ali et al. [228] with permission of Nature, Kong et al. [44] with the permission of Oncotarget, Long et al. [229] with the permission of Annals of Biomedical Engineering, Palaninathan et al. [230] with permission of MRS Communication