Microplastic toxicity in organ tissues

2021 Fiscal Year Annual Research Report

• Project/Area Number: 21F21771
• Allocation Type: Single-year Grants
• Research Institution: Osaka University
• Principal Investigator: 藤田 克昌 大阪大学, 工学研究科, 教授 (80362664)
• Co-Investigator(Kenkyū-buntansha): LINDLEY MATTHEW 大阪大学, 工学(系)研究科(研究院), 外国人特別研究員
• Project Period (FY): 2021-11-18 – 2024-03-31
• Keywords: Raman / Microplastics

Outline of Annual Research Achievements

We have tested the detectability of various microplastics in tissues using microplastic beads placed in mouse liver. Based on these tests, we have made design changes to our Raman line-scan microscope to optimize sample throughput. For producing weathered microplastics, we created a UV exposure apparatus, with four of six different types of microplastics now weathered. Test scans of mouse liver slices from our models have also yielded a bit of serendipity; in addition to assessing tissue health through cytochrome c detection, we tentatively have also detected a secondary biomarker in retinol that should serve as a reporter of liver health. Mouse models have been prepared, with the first microplastic doses using commercial samples to begin shortly.

Current Status of Research Progress

2: Research has progressed on the whole more than it was originally planned.

Reason

A UV photoreactor for plastic weathering was designed under budget and is working smoothly. We are now waiting on SEM-EDX user training (May) to begin characterization of weathered microplastics.
There has been a slight delay in initial microplastic dose-tests with the mice due to availability of commercial fluorescent microplastic samples that are within budget, but we have overcome this.
Plastic detectability tests have been successful and show project measurement is compatible with our microscope.
Our biological collaborators have been a great help in planning and scientific discussion and have afforded us prompt access to fresh tissue samples.

Strategy for Future Research Activity

In R4, we will next test the distribution of microplastics in the mouse following ingestion using fluorescent microplastics and flow cytometry. We will typify the weathering results for our plastic samples. We will implement the planned changes to our rapid-scan Raman microscope and begin measurement of organ slices from microplastic-dosed mice.