Microplastics destabilize lipid membranes by mechanical stretching
Jean-Baptiste Fleury and Vladimir A. Baulin
Significance
The effects of plastic pollution on living organisms is a highly debated subject. There is no direct evidence of high toxicity of microplastic abundantly present in the environment. Nevertheless, microplastic particles can cross many biological barriers and come in direct contact with lipid membranes, which is the last cell protective barrier from the environment.
This study demonstrates that microplastic beads ranging from 1 to 10 μm attach to lipid membranes. This attachment leads to significant stretching of the lipid bilayer without requiring any oxidative, or biological, e.g., inflammatory, reactions. This mechanical stretching can potentially lead to serious dysfunction of the cell machinery.
Abstract
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.
Link | PDF
Jean-Baptiste Fleury and Vladimir A. Baulin
Significance
The effects of plastic pollution on living organisms is a highly debated subject. There is no direct evidence of high toxicity of microplastic abundantly present in the environment. Nevertheless, microplastic particles can cross many biological barriers and come in direct contact with lipid membranes, which is the last cell protective barrier from the environment.
This study demonstrates that microplastic beads ranging from 1 to 10 μm attach to lipid membranes. This attachment leads to significant stretching of the lipid bilayer without requiring any oxidative, or biological, e.g., inflammatory, reactions. This mechanical stretching can potentially lead to serious dysfunction of the cell machinery.
Abstract
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.
Link | PDF
