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Sunburn
Published in Charles Theisler, Adjuvant Medical Care, 2023
Sunscreen or Sunblock: Para-aminobenzoic acid (PABA) 5% or its esters in ethyl alcohol or in a cream or gel are quite effective in helping to prevent sunburn from ultraviolet B rays. Sunscreens with SPF rating at 15 or higher are recommended. Fair-skinned people need an SPF rating of 30 or more. For protection against ultraviolet A rays, it is recommended to use a sunscreen that contains at least one of the following: ecamsule, avobenzone, oxybenzone, titanium dioxide, sulisobenzone, or zinc oxide.2
The Ingestion Pathway
Published in Antonietta Morena Gatti, Stefano Montanari, Advances in Nanopathology From Vaccines to Food, 2021
Antonietta Morena Gatti, Stefano Montanari
To our knowledge, a study has never been conducted showing that the amount of excipients taken is equivalent to that in any way eliminated. Therefore, it is not known whether something remains in the organism, where and how much. As a rule, the excipients in the form of particles are evaluated exclusively from a chemical point of view, and according to this criterion, their reactivity is negligible or, in practical terms, zero. But if one looks at them from the nanopathological point of view, it is clear that those particles are foreign bodies which necessarily behave as such. And the fact becomes particularly important for those who must take a drug in a chronic or, in any case, in a prolonged way over time. But now microand nanoparticles are also used in many sunscreens to block UVA and UVB rays. In the cosmetics industry, they are used in toothpaste, lipsticks, creams, ointments and powders, and there are many industrial foods which contain them as a deliberate addition, if not as ignored pollutants. Though the Food and Drug Administration (FDA) has approved titanium dioxide particles for food, drugs and cosmetics, there is no actual evidence about their safety.
Inhalation Toxicity of Metal Particles and Vapors
Published in Jacob Loke, Pathophysiology and Treatment of Inhalation Injuries, 2020
Titanium dioxide has been considered physiologically inert by all routes (ingestion, inhalation, dermal, and subcutaneous). Previous reports of pulmonary injury following exposure to titanium dioxide are now thought to be due to contamination (e.g., alumina, silica) (Stokinger, 1981). The metal and other salts are also relatively nontoxic except for titanic acid, which, as might be expected, will produce irritation. Inhalation of TiCl4 by dogs caused severe bronchitis, edema, and death, but the toxicity was ascribed to the HCl released following hydrolysis (Lawson, 1961).
Biomaterial engineering surface to control polymicrobial dental implant-related infections: focusing on disease modulating factors and coatings development
Published in Expert Review of Medical Devices, 2023
Samuel S. Malheiros, Bruna E. Nagay, Martinna M. Bertolini, Erica D. de Avila, Jamil A. Shibli, João Gabriel S. Souza, Valentim A. R. Barão
Biomedical engineering technologies have been employed to optimize surface topography, reduce the release of metal particles and ions from the titanium oxide layer, and to use polymers and antimicrobials as surface films and coatings on titanium implants, all to achieve antimicrobial properties while keeping biocompatibility with host bone and connective tissues [24]. Although the evidence has been promising, most newly developed biomaterials have only been tested by limited in vitro models with limited pre-clinical and clinical translatability at the moment [5]. Notably, the existing knowledge for tooth-related polymicrobial infections, such as periodontitis, cannot be simply translated to the implant surface before being tested experimentally. To the best of our knowledge, the factors modulating biofilm accumulation on the implant surface and the pathogenesis and molecular process of peri-implantitis are still under investigation [7], and few clinical studies are considering the development of new implant surfaces or improvement of existing ones to avoid polymicrobial infections.
Issues currently complicating the risk assessment of synthetic amorphous silica (SAS) nanoparticles after oral exposure
Published in Nanotoxicology, 2021
Walter Brand, Petra C. E. van Kesteren, Ruud J. B. Peters, Agnes G. Oomen
For titanium dioxide (TiO2) we recently postulated that high dose levels could negatively affect the uptake and subsequent effects (Brand et al. 2020). We also postulated administration via the diet could negatively affect the uptake of TiO2, in contrast to the impression given by SAS in the present study. Still, matrix-effects could exist for silica, for example due to gel formation at higher concentrations, and have been suggested earlier (van der Zande et al. 2014). We are not aware of studies systematically comparing different administration dosing regimens for SAS. A recent study by Rodríguez-Escamilla et al. (2019) reported toxicological effects on testis in mice after 10week exposure to TiO2, comparing oral gavage of a suspension in water (5mg/kg bw/d) with much higher exposures levels through feed pellets (equivalent to 102, 682 or 1379mg/kg bw/d). The study found effects through oral gavage similar to up to a 260 times higher dose through pelleted feed, illustrating the importance of the dosing regimen (Rodríguez-Escamilla et al. 2019). Unfortunately, the study did not take biokinetics of tissue distribution into account.
A methodology for developing key events to advance nanomaterial-relevant adverse outcome pathways to inform risk assessment
Published in Nanotoxicology, 2021
Sabina Halappanavar, James D. Ede, Indrani Mahapatra, Harald F. Krug, Eileen D. Kuempel, Iseult Lynch, Rob J. Vandebriel, Jo Anne Shatkin
The Nano-AOP database was searched using the strategy described in Supplemental Appendix 2. The individual studies in the database were analyzed after filtering for ‘TiO2’ MN, and individual entries in the database were checked for the cellular events/KEs ‘ER stress’, ‘ROS’, ‘inflammasome’, ‘caspase’, ‘IL-1/TNF’. Out of 180 experiments with TiO2 MN, 77 were found for ‘Titanium dioxide’ (any size/shape/coating, in vivo and in vitro – various cell lines and doses) that measured ‘ROS’ (53) or ‘inflammasome’ (20) or ‘caspase-1’ (4), and were used for further analysis (it was found that the KE of ER stress was not measured in any of the studies in the database). Eight experiments (3 publications) measured ‘ROS’, ‘IL-1’ and ‘TNF-α’. Sixteen experiments (4 publications) measured ‘ROS’ and ‘TNF-α’. Nineteen experiments (6 publications) measured ‘inflammasome’ and ‘IL-1’. No experiment measured ‘inflammasome’, IL-1’ and ‘NF-κB’. In all, the search resulted in 46 experiments belonging to 11 publications that were evaluated separately for weight of evidence.