肝臓の生体模倣システムにおける細胞障害性の長期非侵襲的評価

抄録

Successful implementation of microphysiological systems (MPS) into drug discovery requires close communication between model developers and end-users to connect emerging technologies and context of use to build better systems (1). We have evaluated not only development devices but also commercial devices in the AMED project. Each of these devices has its own characteristics, and it was considered desirable to make the best use of those characteristics. For that purpose, the user needs to understand each device and select the device that suits each purpose.

In this study, we collaboratively evaluated a new MPS as a tool for detecting hepatotoxicity after repeated exposure to chemicals. In addition, we explored the advantages of non-invasive monitoring, such as by optical coherence tomography (OCT), in the long-term culture in the MPS.

We studied a new MPS device, consisting of a circulating small intestine-liver two-organ connection device developed at the Matsunaga Laboratory, Graduate School of Pharmaceutical Sciences, Nagoya City University (2). Human primary hepatocytes were seeded onto micro-patterned culture surfaces coated with mouse 3T3 feeder cells to form liver spheroids. The liver spheroids were exposed to acetaminophen (APAP) for 7 days, and the cytotoxicity of APAP was evaluated by ATP assay. Albumin, and APAP and its metabolites in the culture media were measured. Cell morphology was recorded by a phase-contrast microscopy and OCT. OCT data underwent image analysis.

After APAP treatment, the appearance of the spheroids changed to a black-coloration. APAP concentration-dependent ATP reduction was observed, suggesting that this liver MPS is strongly able to detect hepatotoxicity after repeated exposure to potential toxicants. Image analysis of OCT data succeeded in counting spheroid numbers. In addition, APAP concentration-dependent decreases in volume, height, and surface area were observed. Albumin also showed an APAP-dependent reduction in culture media.

This liver MPS is potentially applicable to the assessment of hepatotoxicity of chemicals after repeated exposure. OCT is useful for non-invasive monitoring of cellular morphology by image analysis.

[Reference] (1) Biol. Pharm. Bull., 43 375-383(2020).

(2) http://www.scetra.or.jp/business/

[Funding] This research was supported in part by the AMED-MPS project