Development of a polystyrene-based microplastic model for bioaccumulation and biodistribution study using...

Area of Science:

• Environmental Science
• Nuclear Chemistry
• Materials Science

Background:

• Microplastic and nanoplastic pollution poses significant environmental and human health risks.
• Conventional methods for tracking microplastics are often complex and require animal testing.
• Nuclear techniques offer a sensitive, accurate, and real-time alternative for tracing microplastics.

Purpose of the Study:

• To develop and evaluate radiolabeled microplastics as tracers for environmental behavior studies.
• To assess the stability of radiolabeled microplastics in various environmentally relevant media.

Main Methods:

• Polystyrene sulfonate-based microplastics (PSM) with a size of approximately 3.6 μm were synthesized.
• PSM were radiolabeled using iodine-131 (¹³¹I) and zinc-65 (⁶⁵Zn).
• Stability of radiolabeled PSM was tested in seawater, phosphate buffer saline (PBS), and human serum albumin (HSA) over fifteen days.

Main Results:

• PSM labeled with ¹³¹I demonstrated high stability (>90%) in seawater and PBS for fifteen days.
• PSM-131I showed reduced stability (50-60% after 9 days) in human serum albumin (HSA).
• PSM labeled with ⁶⁵Zn exhibited poor stability (<50%) in the tested conditions.

Conclusions:

• Iodine-131 labeled polystyrene sulfonate microplastics (PSM-131I) are a stable and promising radiotracer for microplastic environmental studies.
• The stability of PSM-131I is dependent on the medium, with reduced performance in biological fluids like HSA.
• Zinc-65 labeled microplastics are not suitable for long-term environmental tracing due to instability.