title: A new biocompatible nanocomposite as a promising constituent of sunscreens.
abstract: Skin naturally uses antioxidants to protect itself from the damaging effects of sunlight. If this is not sufficient, other measures have to be taken. Like this, hydroxyapatite has the potential to be applied as an active constituent of sunscreens since calcium phosphate absorbs in the ultraviolet region (UV). The objective of the present work was to synthesize a hydroxyapatite-ascorbic acid nanocomposite (HAp/AA-NC) as a new biocompatible constituent of sunscreens and to test its efficiency with skin cell models. The synthesized HAp/AA-NC was characterized by Fourier transform infrared spectroscopy, transmission electron microscopy, absorption spectrophotometry and X-ray diffraction analysis. The protective effect of the construct was tested with respect to viability and intracellular reactive oxygen species (ROS) generation of primary human dermal fibroblasts (SKIN) and human epidermal keratinocytes (HaCaT). Both cell lines were irradiated with UV light, λmax=254 nm with a fluence of 25 mJ cm(-2) to mimic the effect of UV radiation of sunlight on the skin. Results showed that HAp/AA-NC had a stimulating effect on the cell viability of both, HaCaT and SKIN cells, relative to the irradiated control. Intracellular ROS significantly decreased in UV irradiated cells when treated with HAp/AA-NC. We conclude that the synthesized HAp/AA-NC have been validated in vitro as a skin protector against the harmful effect of UV-induced ROS.
authors.affiliation: Department of Laser Applications in Photochemistry, National Institute of Laser Enhanced Sciences, Cairo University, Egypt. Electronic address: rehabamin@niles.edu.eg.
authors.forename: Rehab M
authors.initials: RM
authors.lastname: Amin
authors.affiliation: Department of Laser Applications in Photochemistry, National Institute of Laser Enhanced Sciences, Cairo University, Egypt; University of Bath, Department of Chemistry, Bath BA2 7AY, UK.
authors.forename: Souad A
authors.initials: SA
authors.lastname: Elfeky
authors.affiliation: Department of Molecular Biology, University of Salzburg, Hellbrunnerstr. 34, 5020 Salzburg, Austria.
authors.forename: Thomas
authors.initials: T
authors.lastname: Verwanger
authors.affiliation: Department of Molecular Biology, University of Salzburg, Hellbrunnerstr. 34, 5020 Salzburg, Austria.
authors.forename: Barbara
authors.initials: B
authors.lastname: Krammer
mesh_terms: D001205:Ascorbic Acid / Q000737:chemistry; D001672:Biocompatible Materials / Q000737:chemistry* / Q000633:toxicity; D002470:Cell Survival / Q000187:drug effects / Q000528:radiation effects; D002478:Cells, Cultured; D017886:Durapatite / Q000737:chemistry; D006801:Humans; D046529:Microscopy, Electron, Transmission; D053761:Nanocomposites / Q000737:chemistry*; D017382:Reactive Oxygen Species / Q000378:metabolism; D017550:Spectroscopy, Fourier Transform Infrared; D013473:Sunscreening Agents / Q000737:chemistry* / Q000633:toxicity; D014466:Ultraviolet Rays; D014961:X-Ray Diffraction
chemical_list: D001672:Biocompatible Materials; D017382:Reactive Oxygen Species; D013473:Sunscreening Agents; D017886:Durapatite; D001205:Ascorbic Acid
keywords: Ascorbic acid; Dermal fibroblasts; Hydroxyapatite; Keratinocytes; Nanocomposite; Sunscreens