Kinetic effects of TiO2 fine particles and nanoparticles aggregates on the nanomechanical properties of human neutrophils assessed by force spectroscopy

Abstract

BackgroundIncreasing applications of titanium dioxide (TiO2) fine particles (FPs) and nanoparticles (NPs) require coupled knowledge improvement concerning their biokinetic effects. Neutrophils are quickly recruited to titanium implantation areas. Neutrophils mechanical properties display a crucial role on cell physiology and immune responsive functions. Then, micro and nanomechanical characterization assessed by force spectroscopy (FS) technique has been largely applied in this field.ResultsScanning electron microscopy (SEM) images highlighted neutrophils morphological changes along TiO2 FPs and NPs aggregates exposure time (1, 5, and 30 min) compared to controls. FS approaches showed an increasing on attraction forces to TiO2 FPs and NPs treated neutrophils. This group depicted stronger stiffness features than controls just at 1 min of exposure. Treated neutrophils showed a tendency to increase adhesive properties after 1 and 5 min of exposure. These cells maintained comparatively higher elasticity behavior for a longer time possibly due to intense phagocytosis and cell stiffness opposing to the tip indentation. Neutrophils activation caused by FPs and NPs uptake could be related to increasing dissipated energy results.ConclusionsMechanical modifications resulted from TiO2 FPs and NPs aggregates interaction with neutrophils showed increasing stiffness and also cell morphology alteration. Cells treatment by this metal FPs and NPs caused an increase in attractive forces. This event was mainly observed on the initial exposure times probably regarding to the interaction of neutrophils membrane and phagocytosis. Similar results were found to adhesion forces and dissipated energy outcomes. Treated cells presented comparatively higher elasticity behavior for a longer time. SEM images clearly suggested cell morphology alteration along time course probably related to activation, cytoskeleton rearrangement and phagocytosis. This scenario with increase in stiffness strongly suggests a direct relationship over neutrophil rolling, arrest, and transmigration. Scrutinizing these interactions represents an essential step to clarify the mechanisms involved on treatments containing micro and nanomaterials and their fates on the organisms.

Titanium Dioxide Nanoparticles Increase Superoxide Anion Production by Acting on NADPH Oxidase

“…TiO 2 NPs aggregates are known to interact with neutrophils. Recent work by SEM [ 19 ] showed increased stiffness of the membrane and cell morphology alteration. Our present results indicate that this stiffness would not impede the NADPH oxidase functioning.…”

“…TiO 2 NP-mediated ROS responses have been reported to orchestrate a series of pathological events leading to genotoxicity, immunotoxicity, neurotoxicity and carcinogenicity [ 17 , 18 ]. Neutrophils have been shown to be quickly recruited to titanium dioxide areas [ 19 ]. Moreover, cellular internalization of TiO 2 and ZnO NPs has been shown to activate immune cells including macrophages and neutrophils that contribute to ROS production [ 20 – 24 ].…”

Cobalt and Titanium nanoparticles influence on human osteoblast mitochondrial activity and biophysical properties of their cytoskeleton

“…size and shape) impacts proliferation and differentiation of cells along with wear particles concentration [29]. Particles with diameter smaller than 1 µm are more easily phagocytosed compared to larger counterparts [32] and elongated particles induce stronger cellular reactions than round particles [29], [33], [34]. Moreover, particles concentrations used in this study were the same range as studies and found in patient tissues [29], [35].…”

Evaluation of the Toxicity of Silver/Silica and Titanium Dioxide Particles in Mammalian Cells

“…Also, because of their small size, these particles may enter plant and animals cells and reach critical areas in organelles tissues and organs 12 . Not nanoscale TiO2 is considered to be a non-toxic biocide 13,14 and its rutile crystal form is recommended as safe to use in cosmetic and pharmaceutical applications 15 . Reckoning with the above discussions, a range of studies has been performed in normal and cancerous cell trials to determine the role of different particles in toxicity 2,16,17,18 .…”