Crumpling of silver nanowires by endolysosomes strongly reduces toxicity.

Fibrous particles interact with cells and organisms in complex ways that can lead to cellular dysfunction, cell death, inflammation, and disease. The development of conductive transparent networks (CTNs) composed of metallic silver nanowires (AgNWs) for flexible touchscreen displays raises new possibilities for the intimate contact between novel fibers and human skin. Here, we report that a material property, nanowire-bending stiffness that is a function of diameter, controls the cytotoxicity of AgNWs to nonimmune cells from humans, mice, and fish without deterioration of critical CTN performance parameters: electrical conductivity and optical transparency. Both 30- and 90-nm-diameter AgNWs are readily internalized by cells, but thinner NWs are mechanically crumpled by the forces imposed during or after endocytosis, while thicker nanowires puncture the enclosing membrane and release silver ions and lysosomal contents to the cytoplasm, thereby initiating oxidative stress. This finding extends the fiber pathology paradigm and will enable the manufacture of safer products incorporating AgNWs.

BLISS: A Bioorthogonal Dual-Labeling Strategy to Unravel Lignification Dynamics in Plants.

A better in vivo understanding of lignin formation within plant cell walls will contribute to improving the valorization of plant-derived biomass. Although bioorthogonal chemistry provides a promising platform to study the lignification process, methodologies that simultaneously detect multiple chemical reporters in living organisms are still scarce. Here, we have developed an original bioorthogonal labeling imaging sequential strategy (BLISS) to visualize and analyze the incorporation of both p-hydroxyphenyl (H) and guaiacyl (G) units into lignin in vivo with a combination of strain-promoted and copper-catalyzed azide-alkyne cycloadditions. On our path to BLISS, we designed a new azide-tagged monolignol reporter for H units in metabolic lignin engineering and used it in conjunction with an alkyne-tagged G unit surrogate to study lignification dynamics in flax. Here, we show that BLISS provides precise spatial information on the zones of active lignification and reveals polarization in single-cell lignification dynamics.