Influence of TiO2 nanocomposite UV filter surface chemistry and their interactions with organic UV filters on uptake and toxicity toward cultured fish gill cells

Changes in life history parameters and expression of key genes of Brachionus plicatilis exposed to a combination of organic and inorganic ultraviolet filters

The increasing use of ultraviolet filters has become an emerging contaminant on the coast, posing potential ecological risks. Rotifers are essential components of marine ecosystems, serving as an association between primary producers and higher-level consumers. These organisms frequently encounter ultraviolet filters in coastal waters. This study aimed to assess the comprehensive effects of organic ultraviolet filters, specifically 2-ethylhexyl-4-methoxycinnamate (EHMC), and inorganic ultraviolet filters, namely, titanium dioxide nanoparticles (TiO2 NPs), on the rotifer Brachionus plicatilis. We exposed B. plicatilis to multiple combinations of different concentrations of EHMC and TiO2 NPs to observe changes in life history parameters and the expression of genes related to reproduction and antioxidant responses. Our findings indicated that increased EHMC concentrations significantly delayed the age at first reproduction, reduced the total offspring, and led to considerable alterations in the expression of genes associated with reproduction and stress. Exposure to TiO2 NPs resulted in earlier reproduction and decreased total offspring, although these changes were not synchronised in gene expression. The two ultraviolet filters had a significant interaction on the age at first reproduction and the total offspring of rotifer, with these interactions extending to the first generation. This research offers new insights into the comprehensive effects of different types of ultraviolet filters on rotifers by examining life history parameters and gene expression related to reproduction and stress, highlighting the importance of understanding the impacts of sunscreen products on zooplankton health.

Effect of montmorillonite (MMT) on the properties of soybean meal protein isolate-based nanocomposite film loaded with debittered kinnow peel powder

The synthetic, non-renewable nature and harmful effects of plastic packaging have led to the synthesis of eco-friendly renewable bio-nanocomposite film. The present work was aimed at the formulation and characterization of bio-nanocomposite film using soybean meal protein, montmorillonite (MMT), and debittered kinnow peel powder. The composition of film includes protein isolate (5% w/v), glycerol (50% w/w), peel powder (20% w/w), and MMT (0.5-2.5% w/w). Incorporation of MMT in soybean meal protein-based film loaded with kinnow peel powder showed lesser solubility (16.76-26.32%), and swelling ability (142.77-184.21%) than the film prepared without MMT (29.41%, & 229.41%, respectively). The mechanical properties like tensile strength of nanocomposite film improved from 9.41 to 38.69% with the increasing concentration of MMT. The water vapor transmission rate of the nanocomposite film was decreased by 3.45-17.85% when the MMT concentration increased. Fourier-transform infrared spectroscopy and X-ray diffraction analysis showed no considerable change in the structural properties of the film after the addition of MMT. Differential scanning colorimeter analysis revealed the increment in melting temperature (85.33-92.67 °C) of the film with a higher concentration of MMT. Scanning electron microscopy analysis indicated an increased distributed area of MMT throughout the film at higher concentrations. The antimicrobial activity of the film was remarkably increased by 4.96-17.18% with the addition of MMT. The results obtained in the current work confirmed that MMT incorporation in soybean meal protein-based film can augment its properties and can be utilized for enhancing the storage period of food products.

Combined effects of organic and mineral UV-filters on the lugworm Arenicola marina

Pollution from personal care products, such as UV-filters like avobenzone and nano-zinc oxide (nZnO), poses a growing threat to marine ecosystems. To better understand this hazard, especially for lesser-studied sediment-dwelling marine organisms, we investigated the physiological impacts of simultaneous exposure to nZnO and avobenzone on the lugworm Arenicola marina. Lugworms were exposed to nZnO, avobenzone, or their combination for three weeks. We assessed pollutant-induced metabolic changes by measuring key metabolic intermediates in the body wall and coelomic fluid, and oxidative stress by analyzing antioxidant levels and oxidative lesions in proteins and lipids of the body wall. Exposure to UV filters resulted in shifts in the concentrations of Krebs' cycle and urea cycle intermediates, as well as alterations in certain amino acids in the body wall and coelomic fluid of the lugworms. Pathway enrichment analyses revealed that nZnO induced more pronounced metabolic shifts compared to avobenzone or their combination. Exposure to avobenzone or nZnO alone prompted an increase in tissue antioxidant capacity, indicating a compensatory response to restore redox balance, which effectively prevented oxidative damage to proteins or lipids. However, co-exposure to nZnO and avobenzone suppressed superoxide dismutase and lead to accumulation of lipid peroxides and methionine sulfoxide, indicating oxidative stress and damage to lipids and proteins. Our findings highlight oxidative stress as a significant mechanism of toxicity for both nZnO and avobenzone, especially when combined, and underscores the importance of further investigating the fitness implications of oxidative stress induced by these common UV filters in benthic marine organisms.

UV filter occurrence in beach water of the Mediterranean coast - A field survey over 2 years in Palavas-les-Flots, France

OBJECTIVE

A 2-year sampling campaign was realized on French Mediterranean beach (Palavas-les-Flots Hérault) in order to measure the concentration of UV filters released from the sunscreen used by bathers. Multiple factors suspected of playing determining roles in the UV filter pattern in water were explored, such as the seasonal and daily time evolutions, or the vertical and horizontal distributions, and they were regarded through the UV filter characteristics.

METHODS

The beach was monitored during periods of high and low tourist attendance, typically before, during and after the summer peak. The beachgoers attendance was counted. Bathing water was sampled distinctly from the bulk column and from the top surface layer, testing different sampling tools. Sediments and mussels were also sampled and analysed as potential UV filter sinks. Three organic UV filters (octocrylene OCR, avobenzone BMDBM and octyl methoxycinnamate OMC) and one mineral (titanium dioxide TiO2 ) were studied here as representatives of the current cosmetic market.

RESULTS

Summer peak attendance on the beach was confirmed associated with peak levels of UV filter concentration in the bathing water, even more pronounced during a heat wave period. This relation was also observed at day scale with an afternoon peak, suggesting a rapid evolution of the UV filter pattern in water. Contrasted fates were measured between the four studied UV filters, that could be mainly explained by their respective characteristics, i.e. particulate or dissolved, hydrophilic or lipophilic, lifetime. Generally, this resulted in a concentration ranking TiO2  > OCR > OMC > BMDBM, ranging from 0.5 to 500 μg/L. The most lipophilic and recalcitrant OCR was found most vertically differentiated and over concentrated in the top surface layer of water. Finally, a large horizontal heterogeneity was also observed in the UV filter concentration pattern, raising the need for sample replicates that cover a significant area.

CONCLUSION

This work fulfils some knowledge gaps on the issue of UV filter release in coastal environments, not only by providing original field data and methodological recommendations but also importantly in the comparison made of organic and mineral UV filters, which are often considered separately and rarely evaluated at the same time.

Biomineralization: A new tool for developing eco-sustainable Ti-doped hydroxyapatite-based hybrid UV filters

It is well known that the prolonged exposure to UV radiation from sunlight can compromise human health and is particularly damaging to the skin, leading to sunburn, photo-aging and skin cancer. Sunscreen formulations containing UV-filters present a barrier against solar UV and help to mitigate the harmful effects however, concern about their safety for both human and environmental health is still a much-debated topic. EC regulations classify UV-filters depending on their chemical nature, particle size, and mechanism of action. Furthermore, it regulates their use in cosmetic products with specific limitations in terms of concentration (organic UV filters) and particle size and surface modification to reduce their photo-activity (mineral UV filters). The regulations have prompted researchers to identify new materials that show promise for use in sunscreens. In this work, biomimetic hybrid materials composed of titanium-doped hydroxyapatite (TiHA) grown on two different organic templates, derived from animal (gelatin - from pig skin) and vegetable (alginate - from algae) sources. These novel materials were developed and characterized to obtain sustainable UV-filters as a safer alternative for both human and ecosystem health. This 'biomineralization' process yielded TiHA nanoparticles that demonstrated high UV reflectance, low photoactivity, good biocompatibility and an aggregate morphology which prevents dermal penetration. The materials are safe for topical application and for the marine environment; moreover, they can protect organic sunscreen components from photodegradation and yield long-lasting protection.

Phototoxic or Photoprotective?-Advances and Limitations of Titanium (IV) Oxide in Dermal Formulations-A Review

The widespread role of titanium (IV) oxide (TiO₂) in many industries makes this substance of broad scientific interest. TiO₂ can act as both a photoprotector and photocatalyst, and the potential for its role in both applications increases when present in nanometer-sized crystals. Its sunlight-scattering properties are used extensively in sunscreens. Furthermore, attempts have been made to incorporate TiO₂ into dermal formulations of photolabile drugs. However, the propensity to generate reactive oxygen species (ROS) rendering this material potentially cytotoxic limits its role. Therefore, modifications of TiO₂ nanoparticles (e.g., its polymorphic form, size, shape, and surface modifications) are used in an effort to reduce its photocatalytic effects. This review provides an overview of the potential risks arising from and opportunities presented by the use of TiO₂ in skin care formulations.

Availability and effects of n-TiO2 and PCB77 in fish in vitro models of the intestinal barrier and liver under single- and/or co-exposure scenarios

Titanium dioxide nanoparticles (n-TiO₂) and polychlorinated biphenyls (PCBs) can be present in the food of fish, leading to intestinal exposure uptake, and accumulation in inner organs. This study examined combination effects of n-TiO₂ and PCB77 in vitro models of the fish intestinal epithelium and liver, i.e., RTgut-GC cell cultures grown in ThinCerts™ and RTL-W1 cell cultures grown in standard tissue culture plates. Mass spectrometry and microscopy techniques were used to obtain information on nanoparticle translocation across the intestinal barrier model. In addition, the substances' effect on intestinal barrier permeability, cell viability, expression of dioxin - and antioxidant response element -controlled genes, and induction of cytochrome P450 1a (Cyp1a)-dependent ethoxyresorufin-O-deethylase (EROD) activity were assessed. TiO₂ nanoparticles were taken up by RTgut-GC cells and detected in the bottom compartment of the intestinal epithelial barrier model. It was not possible to conclude definitively if n-TiO₂ translocation occurred via transcytosis or paracellular migration but observations of nanoparticles in the lateral space between adjacent epithelial cells were rare. PCB77 (1 and 10 µM, 24 h) did not affect barrier permeability, i.e., n-TiO₂ translocation is probably not facilitated in case of co-exposure. Furthermore, previous and simultaneous exposure to n-TiO₂ (1 and 10 mg/L, 24 h) did not have any influence on PCB77-induced Cyp1a mRNA and enzyme activity levels in RTL-W1 cells. Furthermore, there were no significant differences in expression of antioxidant response element-controlled genes comparing control, single substance, and mixture treatments, not even following long-term exposure (0.01-1 mg/L n-TiO₂ + 1 nM PCB77, 4 weeks). While an underestimation of the effects of n-TiO₂ and PCB77 cannot be fully excluded as concentration losses due to sorption to cell culture plastics were not measured, the results suggest that the test substances probably have a low potential to exhibit combination effects on the assessed endpoints when co-existing in fish tissues.