Sunscreens are ultraviolet radiation (UVR)-absorbing chemicals that attenuate the amount and nature of UVR reaching viable cells in the skin. They are selected and tested for their ability to prevent erythema. No sunscreen prevents photodamage, as it has been demonstrated that suberythemal doses of UVR cause a variety of molecular changes (including DNA damage) in these cells. Furthermore, the spectrum of UVR reaching viable cells is altered by topically applied sunscreen. In this review, the basic aspects of sunscreens and skin photobiology are reviewed briefly. Although there can be no question concerning the efficacy of sunscreens for the prevention of erythema, questions remain because of the possible cumulative effects of chronic suberythemal doses and the increased exposure of skin cells to longer UVR wavelengths. The current major issue surrounding sunscreens involves their ability to protect skin cells against the effects of UVA radiation. These UVA effects may be direct damage (base oxidations) or effects on the skin immune system, yet there is no uniformly accepted method for the evaluation of UVA protection. This review is focused primarily on the latter topic covering action spectra that implicate the need for UVA protection. In addition, in vivo and in vitro methods proposed for the evaluation of candidate sunscreen formulations of UVA protective ability are reviewed. Finally, revisions in the terminology used to describe the protection afforded by sunscreens are suggested. It is proposed that SPF ("sun" protection factor) be renamed "sunburn" protection factor and that "critical wavelength" be designated "long wave index."
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http://dx.doi.org/10.1289/ehp.00108s171 | DOI Listing |
Pharmaceutics
December 2024
School of Pharmacy, Faculty of Medical and Health Sciences, The University of Auckland, Auckland 1023, New Zealand.
Skin ageing, driven predominantly by oxidative stress from reactive oxygen species (ROS) induced by environmental factors like ultraviolet A (UVA) radiation, accounts for approximately 80% of extrinsic skin damage. L-glutathione (GSH), a potent antioxidant, holds promise in combating UVA-induced oxidative stress. However, its instability and limited penetration through the stratum corneum hinder its topical application.
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December 2024
Faculty of Chemical Engineering and Biotechnology, National University of Science and Technology POLITEHNICA of Bucharest, Polizu No 1, 011061 Bucharest, Romania.
The study aims to investigate an improved version of lipid nanocarriers (NLCs) (formulated with functional coconut butter and marula oil) by designing hyaluronic acid (HA) decorated NLC co-loaded with dual UVA (butyl methoxy dibenzoyl methane, BMDBM), UVB absorbers (ethyl-hexyl-salicylate, EHS) and a Raspberry rich polyphenols fraction (RPRF) for development of more natural NLC-based to-pical formulations. : Quality and quantitative attributes of classic- and HA-NLC have been assigned based on particle size, electrokinetic potential, encapsulation efficiency, spectroscopic characteristics, and high-resolution mass spectrometry. To establish the performance profile of antioxidant activity, release of active substances, sun blocking action, and photostability, in vitro studies were conducted.
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January 2025
Department of Ophthalmology, The Quzhou Affiliated Hospital of Wenzhou Medical University, Quzhou People's Hospital, Quzhou, Zhejiang 324000, China; Wenzhou Institute, University of Chinese Academy of Sciences, Wenzhou, Zhejiang 325000, China. Electronic address:
Orb-weaver spiders utilize morphologically differentiated abdominal glands to produce up to seven types of silks throughout their life cycles. Tubuliform silk is unique as it serves to protect developing embryos and hatchlings. However, our current understanding of the relationship between structure and function of tubuliform silk protein remains limited.
View Article and Find Full Text PDFArch Dermatol Res
January 2025
Department of Dermatology, Drexel University College of Medicine, 860 1St Avenue, Suite 8B, Philadelphia, PA, 19406, USA.
UV-A exposure is a major risk factor for melanoma, nonmelanoma skin cancer, photoaging, and exacerbation of photodermatoses. Since people spend considerable time in cars daily, inadequate UV-A attenuation by car windows can significantly contribute to the onset or exacerbation of these skin diseases. Given recent market trends in the automobile industry and known impact of car windows on cumulative lifelong UV damage to the skin, there is a need to comparatively evaluate UV transmission across windows in electric vehicles (EV), hybrid vehicles (HV), and gas vehicles (GV) as well as variability based on year of manufacture and mileage to inform car manufacturers and consumers of the potential for UV exposure to the skin based on vehicle.
View Article and Find Full Text PDFFront Antibiot
September 2024
Department of Agriculture, Food, and Resource Sciences, University of Maryland Eastern Shore, Princess Anne, MD, United States.
is a foodborne pathogenic bacterium that causes salmonellosis worldwide. Also, is considered a serious problem for food safety and public health. Several antimicrobial classes including aminoglycosides, tetracyclines, phenols, and β-Lactams are used to treat infections.
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