Daily Cosmetic Research Analysis

Quantitative risk assessment (QRA) for dermal sensitization is essential for determining safe concentrations of skin sensitizers in consumer products. The fragrance industry developed the QRA2 approach, which uses the No Expected Sensitization Induction Level (NESIL) as a starting reference dose or point of departure (PoD). Animal alternatives for potency assessment have emerged to calculate quantitative PoDs. One such alternative is in vitro-based regression models. Herein, a framework for incorporating regression models into next-generation risk assessment (NGRA) is presented. The framework begins with hazard assessment using in vitro methods (OECD Guideline 497), followed by PoD calculation through regression models, and completed with QRA2. After determining a PoD, uncertainty factors may be considered to derive a new approach methodology NESIL (NAM-NESIL). Case studies are presented with two sensitizers, p-mentha-1,8-dien-7-al (CAS # 2111-75-3) and 3-propylidenephthalide (CAS # 17369-59-4), calculating acceptable exposure levels (AELs) for products like deodorants and bar soaps. Ratios of the AELs to consumer exposure levels (CELs) were then calculated to determine whether the current use is safe. Comparison of QRA based on NAM-NESILs to historically human-derived NESILs supports the reliability of in vitro models. This approach offers a promising alternative for PoD derivation, potentially eliminating the dependence on in-vivo data.

Despite growing interest in anti-aging products and surgical procedures, the mechanistic links between age-based biomechanical tissue alterations and the emergence of a sagged facial appearance have remained relatively unexplored. Here, we provide corresponding insights by leveraging accurate in vivo characterization of the non-linear viscoelastic behavior of cheek cutis and subcutis to inform anatomically-accurate computational face models. We report that age-based changes in tissue deformability are location- and layer-specific, measuring stronger softening for the subcutis (2.7×-14.2×) than for the cutis (1.9×). Corresponding experimentally-informed simulations further indicate that biomechanical alterations of the cutis, subcutis, and dermal anchoring structures are necessary conditions towards recapitulating jowl formation, though each insufficient on its own. We relate this to the mechanical gradients across facial tissues, whereby softening of the stiffer outer layers is required for deeper tissue aging to appreciably influence the facial appearance and significantly activate stretch-based mechanobiological pathways driving skin tension relaxation. We envision these findings to inform the development of biophysically grounded surgical and cosmetic anti-aging strategies specifically targeting individual facial tissue layers.

Ultraviolet filters (UVFs), widely used in industrial and personal care products, are emerging environmental contaminants of great concern because of their persistence, bioaccumulation and toxicity. Sediments are generally considered the reservoir and secondary source of UVFs, yet knowledge of the occurrence of these emerging contaminants in coastal sediments on a large geographical scale remains unknown. In this study, 31 out of 37 target UVFs were detected in 91 sediment samples collected from 43 coastal cities of China. Benzophenone UVFs exhibited the highest mean total concentration of 5374.8 pg/g, followed by benzotriazole (3298.3 pg/g), salicylate (3094.1 pg/g) and triazin UVFs (61.2 pg/g), respectively. Spatial analysis revealed significantly higher UVF concentrations ranging from 1839 pg/g to 82,308 pg/g in coastal sediments from the Yellow Sea compared with those of the South China Sea, the East China Sea and the Bohai Sea (p < 0.05). Source apportionment indicated that the emissions from industrial productions, cosmetics and personal care products are major contributors to UVF contamination. A nationwide mass inventory identified the Liaodong Peninsula, Yangtze River Estuary, Pearl River Estuary, and north-east Hainan Province as UVF accumulation hotspots, influenced by tourism, industrial activities, and ocean currents. Ecological risk assessment showed that seven UVFs, including Benzophenone-7 (BP-7), 2-(benzotriazol-2-yl)-4-tert-butylphenol (UV-PS), 2-tert-butyl-6-(5-chlorobenzotriazol-2-yl)-4-methylphenol (UV-326), 2,4-ditert-butyl-6-(5-chlorobenzotriazol-2-yl) phenol (UV-327), 2-(benzotriazol-2-yl)-4-(2,4,4-trimethylpentan-2-yl) phenol (UV-329), 2-Ethylhexyl salicylate (EHS) and Homosalate (HMS), posed significant ecological risks (RQ > 0.1) in coastal sediments. This work delivers the first nationwide assessment of four classes of UVFs contamination in coastal sediments of China, providing critical data for their environmental mitigation and management.