bims-orenst 2022-10-09 papers

Issue of 2022–10–09
four papers selected by

Talanta. 2022 Sep 29. pii: S0039-9140(22)00767-6. [Epub ahead of print]253 123971

Construction of a novel blood brain barrier-glioma microfluidic chip model: Applications in the evaluation of permeability and anti-glioma activity of traditional Chinese medicine components.

Yiwei Shi, Xiaoli He, Hui Wang, Jianying Dai, Jiahao Fang, Yuzhen He, Xiaofei Chen, Zhanying Hong, Yifeng Chai.

Since most anti-glioma drug candidates hardly permeate through the blood-brain barrier (BBB), preclinical models that can integrate the complexity of the tumor microenvironment and the structure and function of the BBB is urgently needed for the treatment of glioma. Herein, we constructed an in vitro BBB-glioma microfluidic chip model lined by primary human brain microvascular endothelial cells, pericytes, astrocytes and glioma cells, which could recapitulate the high level of barrier function of the in vivo human BBB and glioma microenvironment. The BBB unit in BBB-glioma microfluidic chip (BBB-U251 chip) displayed selective permeability to fluorescein isothiocyanate isomer-dextran (FITC-dextran) with different molecular weights and three model drugs with different permeability behavior across BBB, which indicated that this glioma model included a functional barrier. Six potential anti-glioma components in traditional Chinese medicine (TCM) were delivered into the blood channel and the permeated amount was quantified by high-performance liquid chromatography combined with ultraviolet (HPLC-UV). The permeated drugs then directly acted on 3D cultured glioma cells (U251) to evaluate the drug efficacy. The results of permeability coefficients of drugs showed that the data were closer to the in vivo data of traditional Transwell model. The effect of the drugs on U251 cells in the BBB-U251 chip was significantly lower due to the existence of BBB. Drug responses on glioma demonstrated the necessity to take BBB into account during the development of anti-glioma new drugs. Therefore, this 3D glioma microfluidic models integrating the BBB functionality can be a useful platform for screening the anticancer drug for brain tumors.

Keywords: Active components of traditional Chinese medicine; Blood-brain barrier; Drug screening; Microfluidic chip; Permeability; Tumor microenvironment

DOI: https://doi.org/10.1016/j.talanta.2022.123971

Microsyst Nanoeng. 2022 ;8 109

Measurement of oxygen consumption rates of human renal proximal tubule cells in an array of organ-on-chip devices to monitor drug-induced metabolic shifts.

Samuel H Kann, Erin M Shaughnessey, Jonathan R Coppeta, Hesham Azizgolshani, Brett C Isenberg, Else M Vedula, Xin Zhang, Joseph L Charest.

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.

Keywords: Chemistry; Engineering

DOI: https://doi.org/10.1038/s41378-022-00442-7

ACS Biomater Sci Eng. 2022 Oct 05.

Evaluation of Human Performance Aiding Live Synthetically Engineered Bacteria in a Gut-on-a-Chip.

M Tyler Nelson, Heidi G Coia, Corey Holt, Eric S Greenwood, Latha Narayanan, Peter J Robinson, Elaine A Merrill, Vaughn Litteral, Michael S Goodson, Roland J Saldanha, Matthew W Grogg, Camilla A Mauzy.

Synbiotics are a new class of live therapeutics employing engineered genetic circuits. The rapid adoption of genetic editing tools has catalyzed the expansion of possible synbiotics, exceeding traditional testing paradigms in terms of both throughput and model complexity. Herein, we present a simplistic gut-chip model using common Caco2 and HT-29 cell lines to establish a dynamic human screening platform for a cortisol sensing tryptamine producing synbiotic for cognitive performance sustainment. The synbiotic, SYN, was engineered from the common probiotic E. coli Nissle 1917 strain. It had the ability to sense cortisol at physiological concentrations, resulting in the activation of a genetic circuit that produces tryptophan decarboxylase and converts bioavailable tryptophan to tryptamine. SYN was successfully cultivated within the gut-chip showing log-phase growth comparable to the wild-type strain. Tryptophan metabolism occurred quickly in the gut compartment when exposed to 5 μM cortisol, resulting in the complete conversion of bioavailable tryptophan into tryptamine. The flux of tryptophan and tryptamine from the gut to the vascular compartment of the chip was delayed by 12 h, as indicated by the detectable tryptamine in the vascular compartment. The gut-chip provided a stable environment to characterize the sensitivity of the cortisol sensor and dynamic range by altering cortisol and tryptophan dosimetry. Collectively, the human gut-chip provided human relevant apparent permeability to assess tryptophan and tryptamine metabolism, production, and transport, enabled host analyses of cellular viability and pro-inflammatory cytokine secretion, and succeeded in providing an efficacy test of a novel synbiotic. Organ-on-a-chip technology holds promise in aiding traditional therapeutic pipelines to more rapidly down select high potential compounds that reduce the failure rate and accelerate the opportunity for clinical intervention.

Keywords: host−microbe interactions; microfluidics; microphysiological systems; synbiotic; synthetic biology

DOI: https://doi.org/10.1021/acsbiomaterials.2c00774

Lab Chip. 2022 Oct 07.

Tissue clearing of human iPSC-derived organ-chips enables high resolution imaging and analysis.

Briana N Ondatje, Samuel Sances, Michael J Workman, Clive N Svendsen.

Engineered microfluidic organ-chips enable increased cellular diversity and function of human stem cell-derived tissues grown in vitro. These three dimensional (3D) cultures, however, are met with unique challenges in visualization and quantification of cellular proteins. Due to the dense 3D nature of cultured nervous tissue, classical methods of immunocytochemistry are complicated by sub-optimal light and antibody penetrance as well as image acquisition parameters. In addition, complex polydimethylsiloxane scaffolding surrounding the tissue of interest can prohibit high resolution microscopy and spatial analysis. Hyperhydration tissue clearing methods have been developed to mitigate similar challenges of in vivo tissue imaging. Here, we describe an adaptation of this approach to efficiently clear human pluripotent stem cell-derived neural tissues grown on organ-chips. We also describe critical imaging considerations when designing signal intensity-based approaches to complex 3D architectures inherent in organ-chips. To determine morphological and anatomical features of cells grown in organ-chips, we have developed a reliable protocol for chip sectioning and high-resolution microscopic acquisition and analysis.

DOI: https://doi.org/10.1039/d2lc00116k