Estimated millions of tons of plastic are dumped annually into oceans. Plastic has been produced only for 70 y, but the exponential rise of mass production leads to its widespread proliferation in all environments. As a consequence of their large abundance globally, microplastics are also found in many living organisms including humans. While the health impact of digested microplastics on living organisms is debatable, we reveal a physical mechanism of mechanical stretching of model cell lipid membranes induced by adsorbed micrometer-sized microplastic particles most commonly found in oceans. Combining experimental and theoretical approaches, we demonstrate that microplastic particles adsorbed on lipid membranes considerably increase membrane tension even at low particle concentrations. Each particle adsorbed at the membrane consumes surface area that is proportional to the contact area between particle and the membrane. Although lipid membranes are liquid and able to accommodate mechanical stress, the relaxation time is much slower than the rate of adsorption; thus, the cumulative effect from arriving microplastic particles to the membrane leads to the global reduction of the membrane area and increase of membrane tension. This, in turn, leads to a strong reduction of membrane lifetime. The effect of mechanical stretching of microplastics on living cells membranes was demonstrated by using the aspiration micropipette technique on red blood cells. The described mechanical stretching mechanism on lipid bilayers may provide better understanding of the impact of microplastic particles in living systems.

据估计，每年有数百万吨塑料被倾倒到海洋中。塑料仅生产了 70 年，但大规模生产的指数级增长导致其在所有环境中广泛扩散。由于它们在全球范围内的大量存在，微塑料也存在于包括人类在内的许多生物体中。虽然消化的微塑料对生物体的健康影响尚有争议，但我们揭示了由海洋中最常见的吸附的微米级微塑料颗粒诱导的模型细胞脂质膜机械拉伸的物理机制。结合实验和理论方法，我们证明吸附在脂质膜上的微塑料颗粒即使在低颗粒浓度下也会显着增加膜张力。吸附在膜上的每个颗粒消耗的表面积与颗粒和膜之间的接触面积成正比。尽管脂质膜是液体并且能够承受机械应力，但松弛时间比吸附速度慢得多；因此，从到达的微塑料颗粒到膜的累积效应导致膜面积的整体减小和膜张力的增加。这反过来又导致膜寿命大大缩短。通过对红细胞使用抽吸微量移液器技术证明了微塑料机械拉伸对活细胞膜的影响。所描述的对脂质双层的机械拉伸机制可以更好地理解微塑料颗粒在生命系统中的影响。