Carbon Nanotube-Induced Loss of Multicellular Chirality on Micropatterned Substrate Is Mediated by Oxidative Stress

Abstract

Carbon nanotubes (CNTs) are receiving much attention in medicine, electronics, consumer products, and next-generation nanocomposites because of their unique nanoscale properties. However, little is known about the toxicity and oxidative stress related anomalies of CNTs on complex multicellular behavior. This includes cell chirality, a newly discovered cellular property important for embryonic morphogenesis and demonstrated by directional migration and biased alignment on micropatterned surfaces. In this study, we report the influence of single-walled carbon nanotubes (SWCNTs) on multicellular chirality. The incubation of human umbilical vein endothelial cells (hUVECs) and mouse myoblasts (C2C12) with CNTs at different doses and time points stimulates reactive oxygen species (ROS) production and intra- and extracellular oxidative stress (OS). The OS-mediated noxious microenvironment influences vital subcellular organelles (e.g., mitochondria and centrosomes), cytoskeletal elements (microtubules), and vinculin rich focal adhesions. The disorientated nuclear-centrosome (NC) axis and centriole disintegration lead to a decreased migration rate and loss of directional alignment on micropatterned surfaces. These findings suggest that CNT-mediated OS leads to loss of multicellular chirality. Furthermore, the in vitro microscale system presented here to measure cell chirality can be extended as a prototype for testing toxicity of other nanomaterials.

Cellular and Nuclear Alignment Analysis for Determining Epithelial Cell Chirality

“…Results were similar to those generated by the intensity gradient based analysis, which have been used in several studies 18, 25, 28 , and the only slight deviation was in the final count of CCW against NC (non-chiral) rings.…”

“…Cell alignment has been identified as a chiral measure and used for several studies 18, 25, 28 . As the nucleus tends to align themselves with the cells 4, 30 , the chiral nuclear alignment is partially expected.…”

“…The scale of chiral bias of epithelial cells was shown to depend on cell-cell adhesion 28 . Cells lost their distinct chirality when exposed to carbon nanotubes due to oxidative stress, suggesting a potential application of cell chirality as a biomarker for detecting cell toxicity 18 . Chen et al .…”

Multiaxial Polarity Determines Individual Cellular and Nuclear Chirality

“…, differences between the left and right frontal lobes) of higher mammals have long been appreciated 22, 26 . Changes in cell chirality have been associated with cell phenotype and oxidative stress 35, 47 . Cancer, diabetes, and other disorders can also cause birth defects in LR asymmetry 2, 22, 32 .…”

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“…These include [55][56][57][58] Gidwani and Singh have reviewed the possibility and opportunities of using nanoparticles to cross the blood brain barrier [59]. Singh et al, also consider the use of nanoparticles in treating multiple sclerosis and the safety of using carbon nanoparticles in theranostic applications [60,61].…”