Toxicity Associated with the Photo Catalytic and Photo Stable Forms of Titanium Dioxide Nanoparticles Used in Sunscreen lotion

Abstract

Abbreviations: IARC, international agency for research on cancer; UV, ultraviolet; QD, quantum dot; ROS, reactive oxygen species; PBS, phosphate buffered saline; CB, conduction band Photo catalytic nano-TiO 2 is in demand for remediation, sterilization and sanitation, whereas photos table nano-TiO 2 is MOJ Toxicol. 2015;1(3):78-94. 78 AbstractThe increasing number of applications using titanium dioxide nanoparticles (nano-TiO 2 ) highlights the need to continuously and systematically investigate its toxicity. Particle size, surface area and dose are the classical parameters considered when performing toxicity studies. However, consideration of the size-related properties and altered reactivity can unveil complex and unexpected phenomena arising from the interplay of the different factors. In addition to particle size, altered reactivity can be induced by intentional or unintentional modifications of the nanoparticles by their surrounding matrix. This effect could potentially influence the nanoparticles' band gap, surface reactivity, agglomeration, mobility and photo catalytic behavior. The remarkable ability to absorb impurities from the surrounding medium could transform nano-TiO 2 into a surrogate carrier of trace elements (e.g., heavy metal ions), which heightens their transportation and intracellular accumulation. This review outlines the different characteristics and interactions that may contribute to the underlying mechanisms of health and environmental toxicity of nano-TiO 2 , and identifies gaps in current understanding.

Characterisation of Engineered Nanomaterials in Nano-Enabled Products Exhibiting Priority Environmental Exposure

“…The incorporation of rutile [ 4 , 13 , 19 ], anatase [ 4 , 19 , 20 ], brookite [ 21 ], or a mixture of rutile and anatase [ 21 ] in products has been reported previously. Rutile nTiO 2 is preferred because of its high UV absorption gap (wavelength of 407 vs. 387 nm for anatase) [ 22 ] and because of the low photo-reactivity compared to highly reactive anatase that can produce hydroxyl radicals under ultraviolet treatment [ 23 ]. A mixture of TiO 2 forms , as in the case of sample SUN4, appears to be uncommon because only a single case has been reported [ 21 ].…”

“…Nonetheless, advances have been made in this niche of research despite the persisting analytical challenges, resulting in better knowledge and understanding of the characteristics of ENMs in NEPs [ 16 , 17 , 18 , 19 , 20 , 21 , 22 , 23 , 24 , 25 , 26 , 27 ]. Overall, the literature indicates that the ENMs type, quantities, and characteristics in NEPs tend to vary widely even for closely related product types.…”

“…These NEPs are in the product categories of health and fitness (e.g., personal care products, sunscreens, cosmetics) as well as home and garden (cleaning products, paints, laundry cleaning products) [ 5 , 7 , 18 ]. From the different NEPs categories, sunscreens are the most widely studied [ 17 , 18 , 19 , 20 , 21 , 23 , 24 , 25 , 26 ], despite the evidence of high ENMs’ environmental exposure potential in NEPs such as paints [ 33 , 34 , 35 , 36 , 37 ] and other personal care products/cosmetics (e.g., toothpaste, shampoos, and face creams) [ 38 , 39 ]. While nTiO 2 can be expected to be emitted at relatively higher volumes due to their wide application in a spectrum of NEPs, the incorporation of other ENM types such as nAg, nSiO 2 , and nZnO have been reported in other market active NEPs within the health and fitness, as well as home and garden categories [ 7 , 18 , 32 ].…”

TiO2–Alginate–Chitosan-Based Composites for Skin Tissue Engineering Applications

“…According to the literature, the preferred TiO 2 particle sizes are in the nanoscale (for example, between 10 and 50 nm) because they can agglomerate to form larger particles with a reduced void between them, which increases the sun protection factor (SPF). In other words, it increases the efficacy of sunscreen creams against UV radiation, and TiO 2 is more stable in formulations [ 6 , 7 ]. Other things that can influence the stability of TiO 2 particles are the shape, coatings, and crystallinity [ 8 ].…”