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bioRxiv · 10.1101/623678

Isolated occurrences of membrane perturbation by mechanosensing from weakly aggregating silver nanoparticles

Arribas Perez, M.·Moriones, O. H.·Bastus, N. G.·Puntes, V.·Nelson, A.·Beales, P. A.
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Abstract

Silver nanoparticles (AgNPs) have wide-ranging applications, including as additives in consumer products and in medical diagnostics and therapy. Therefore understanding how AgNPs interact with biological systems is important for ascertaining any potential health risks due to the likelihood of high levels of human exposure. Besides any severe, acute effects, it is desirable to understand more subtle interactions that could lead to milder, chronic health impacts. Nanoparticles are small enough to be able to enter biological cells and interfere with their internal biochemistry. The initial contact between nanoparticle and cell is at the plasma membrane. To gain fundamental mechanistic insight into AgNP-membrane interactions, we investigate these phenomena in minimal model systems using a wide-range of biophysical approaches applied to lipid vesicles. We find a strong dependence on the medium composition, where colloidally stable AgNPs in a glucose buffer have negligible effect on the membrane. However, at a physiological salt concentrations, the AgNPs start to weakly aggregate and sporadic but significant membrane perturbation events are observed. Under these latter conditions, transient poration and structural remodelling of some vesicle membranes is observed. We observe that the fluidity of giant vesicle membranes universally decreases by an average of 16% across all vesicles. However, we observe a small population of vesicles display a significant change in mechanical properties with lower bending rigidity and higher membrane tension. Therefore we argue that the isolated occurrences of membrane perturbation by AgNPs are due to low probability mechanosensing events of AgNP aggregation at the membrane.\n\nGRAPHICAL ABSTRACT\n\nO_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=109 SRC=\"FIGDIR/small/623678v1_ufig1.gif\" ALT=\"Figure 1\">\nView larger version (54K):\norg.highwire.dtl.DTLVardef@196aa51org.highwire.dtl.DTLVardef@87c12borg.highwire.dtl.DTLVardef@9b2096org.highwire.dtl.DTLVardef@7877f6_HPS_FORMAT_FIGEXP M_FIG C_FIG

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Arribas Perez, M., Moriones, O. H., Bastus, N. G., Puntes, V., Nelson, A., Beales, P. A.. 2019-04-30. Isolated occurrences of membrane perturbation by mechanosensing from weakly aggregating silver nanoparticles. https://doi.org/10.1101/623678

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