Interactions between oligomeric polymers and lung-sufactant liposome underpinning inhalation risks of airborne plastics

Plastics are widespread in our daily life - from tea bags to coffee cups and water bottles – with various types such as polypropylene (PP), polystyrene (PS), and polyethylene terephthalate (PET), as well as perfluorinated polymers (PFAs). The global annual production of plastic waste was 390.7 million metric tons in 2021, and the amount is projected to triple by 2060.2 Plastics may break down to smaller particles, and ultimately oligomeric polymers, via photo- or bio-degradation. These particles or oligomers ultimately accumulate in the ocean, soil, and atmosphere, posing potential risks to ecosystems and human health. Some of these would become airborne, and humans are particularly vulnerable to inhalation risks of airborne plastics; however, our understanding of how oligomeric polymers interact with the lung is very limited. Here, we propose to study interactions of oligomeric polystyrene and trifluroacetic acid (TFA), which represent the ultimate molecular form of degraded plastics, with liposomes comprising lung lipids/surfactants, using small angle neutron scattering (SANS), varying the oligomer concentraton, solution temperature and salt concentration. The results will add to our fundamental understanding of how oligomers from plastic degradation disrupt the lipid membrane.

塑料在日常生活中无处不在，从茶包、咖啡杯到水瓶均有应用，其品类繁多，涵盖聚丙烯（polypropylene, PP）、聚苯乙烯（polystyrene, PS）、聚对苯二甲酸乙二醇酯（polyethylene terephthalate, PET）以及全氟聚合物（perfluorinated polymers, PFAs）等。2021年全球塑料废弃物年产量达3.907亿吨，预计到2060年该数值将增至原来的三倍²。塑料可通过光降解或生物降解途径分解为更小颗粒，最终形成低聚聚合物。这些颗粒与低聚聚合物最终会在海洋、土壤与大气中积累，对生态系统与人类健康构成潜在威胁。其中部分会进入空气，人类面临吸入空气传播塑料的风险尤为突出，但目前我们对低聚聚合物与肺部的相互作用机制的认知仍十分有限。本研究拟采用小角中子散射（small angle neutron scattering, SANS）技术，通过改变低聚体浓度、溶液温度与盐浓度，探究低聚苯乙烯与三氟乙酸（trifluoroacetic acid, TFA）——即塑料降解后的终极分子形态——与包含肺脂质/表面活性剂的脂质体之间的相互作用。本研究成果将增进我们对塑料降解产生的低聚体如何破坏脂质膜的基础认知。