A Safe-by-Design Approach to "Reef Safe" Sunscreens Based on ZnO and Organic UV Filters.

In recent years, the issue of coral bleaching has led to restrictions in some tropical locations (i.e., Palau, Hawaii, etc.) on the use of some organic UV sunscreen filters, such as oxybenzone and ethyl hexyl methoxycinnamate. In contrast, ZnO is considered safe for marine environments and thus is often used without considering its photocatalytic and oxidative activities related to the generation of O2•- and HO•. Moreover, ZnO needs to be used in combination with other filters to reach higher protection factors. Thus, the study of its interaction with formulations and with organic filters is important in sunscreen technology for the development of safer by-design products. In this work, the photocatalytic activity of zinc oxides with different surface areas (30, 25 and 9 m2/g) and their interaction with selected organic sunscreen filters were investigated. In particular, the ZnO photocatalytic kinetics were studied following the photodegradation of Acid Blue 9 (AB9) observing a first-order reaction with a chemical regime. Our evaluations of the selective inhibitions by hvb+ and HO• demonstrated a substantial predominance of the hydroxide radicals in the expression of the photocatalysis, a trend that was also confirmed by the irradiation of ZnO in an ethanolic solution. Indeed, the formulations containing both ZnO and organic filters defined as "safe" for coral reefs (i.e., Diethylamino Hydroxybenzoyl Hexyl Benzoate, DHHB, and Ethylhexyl Triazone, EHT) showed a non-negligible photocatalytic oxidation and thus the combination was underlined as safe to use.

Comparative Study of SPA Mud from "Bacino Idrominerario Omogeneo dei Colli Euganei (B.I.O.C.E.)-Italy" and Industrially Optimized Mud for Skin Applications.

The term "Salus per aquam (SPA) therapies" refers to therapeutic pathways that includes mud therapy. The therapeutic efficacy of a peloid depends on its chemical and mineralogical composition, as well as its technological properties. Considering the increasing use of clay-based products, it becomes essential to characterize peloids from a qualitative and quantitative point of view. Therefore, this research project aimed to develop a protocol that allows characterization of the chemical-physical composition of sludges collected from different areas of the Homogeneous Euganean Hills Hydromineral Basin (B.I.O.C.E.). The study established a comparative study both between different matrices and between the same matrices at different maturation times, including also a comparison with an industrialized product, that can be used at home, which maintains the characteristics of a natural mud. This research was developed studying the pH, grain size distribution, and chemical and mineralogical composition. Peloids are characterized by a neutral/basic pH and are divided into two categories from a granulometric point of view: The chemical composition allowed observation of numerous correlations between oxides present in the samples and to quantify the presence of heavy metals. Mineralogical analysis made it possible to identify and compare the composition of each sample, also according to the maturation time. Thanks to the methods adopted, important correlations were achieved.

A New Approach to UV Protection by Direct Surface Functionalization of TiO2 with the Antioxidant Polyphenol Dihydroxyphenyl Benzimidazole Carboxylic Acid.

Skin cancer is the most common malignant cancer with an incidence of 1 million cases/year. It is well known that exposure to UV radiation from sunlight leads the most frequent risk factors for several skin disorders including skin cancer. Sunscreen filters represent a valid protection against dangerous effects derived from UV radiation, and they can be divided in organic and inorganic UV filters. Adding, at the product formulation, molecules with booster effect, or also substances that can increase the protecting effectiveness via synergic mechanisms, can further enhance their protection activity. Moreover, this approach leads to develop formulations with high SPF (Sun Protection Factor) with a reduced content of UV filters, this is in line with the recent decisions of yet a few countries (Palau, Thailand, Philippines, and Hawaii) to ban some sunscreen filters to preserve marine environments (i.e., reef). In this work, a new class of sunscreen UV filters has been synthesized, by means the combination of physical filter and Oxisol, an antioxidant molecule with booster effect. In this study, the synthesis of new physical multifunctional ingredients is reported, by means the direct surface functionalization of inorganic filters (in particular TiO2) with Oxisol. In this study, the full characterization of these multifunctional ingredients is also reported, in addition to the cytotoxicity tests, the photocatalytic activity and the rheological properties involved on skin application.

Synthesis and Characterization of New Multifunctional Self-Boosted Filters for UV Protection: ZnO Complex with Dihydroxyphenyl Benzimidazole Carboxylic Acid.

The incidence of skin cancer is increasing both because of climate change and the increase in pollution than people's incorrect habits of sun exposure. In these regards, sunscreen and photoprotection are essential tools in consenting the benefits induced by safe solar light exposition and skin cancer prevention. In this work, a new class of sunscreen filter was synthesized by chemical combination of a physical filter (ZnO) and Oxisol (dihydroxyphenyl benzimidazole carboxylic acid), an antioxidant molecule with booster effect. In this work, a new class of filters with new properties was achieved by direct functionalization of particles surface. A full characterization of this multifunctional ingredient (ZnO-Ox) was conducted: Compared with the simple mixture, the new filter acts as a multifunctional molecule showing a higher Sun Protection Factor (SPF), a better cytotoxic profile (MTT and NRU assay), and anti-acne activity. A strong reduction of photocatalytic activity of ZnO was observed, also improving the safety profile.

Herbal extracts, lichens and biomolecules as natural photo-protection alternatives to synthetic UV filters. A systematic review.

Besides the unquestionable positive effects of solar exposure for human health, UV rays have been widely investigated for toxicology aspects related to excessive UVB and UVA doses, which involve sunburns, skin aging, DNA skin damage and tumorigenesis. At present, synthetic and mineral sunscreens are used to protect against these damages but several natural molecules can provide UV protection, including also synergic effect or enhanced photo stability. Although a large number of herbal extracts and plant origin molecules can deserve potential applications, most of the study reported utilizes different method and different strategies of investigation, making thus difficult to understand the real versus claimed potential. This is possibly one of the reasons why, beside the large body of literature there are no officially approved natural commercial sun-filter but a consistent number of commercially available solar products (sunscreen) on the market that contain herbal derivatives. In this review we have evaluated the papers appeared in the last 15years and we have critically collected the most significant data. Several databases, namely Scifinder, Pubmed, Google Scholar, ISI-Web of Science and Scopus, were used as literature sources; excluding patents and symposium or congress papers. Only articles in the English language have been selected. New formulation, new skin delivery systems, skin penetration enhancers and boosters are most likely the next frontier of investigation in order to better understand the role of whole herbal extracts in exerting their photo protective activity.

A non-invasive method for the in vivo determination of skin antioxidant capacity (IAC-S).

BACKGROUND/PURPOSES: Skin antioxidant network protects cells against oxidative injury and prevents the production of oxidation products. When oxidative stress overwhelms the skin antioxidant capacity, the subsequent modification of the cellular redox apparatus leads to an alteration of cell homeostasis leading to degenerative processes. In the dermocosmetic field, the topical application of antioxidants is often suggested as a possible strategy to prevent and modulate oxidative skin damages. Continuing our studies addressed to set-up new bio-engineering protocols for the claim substantiation of antioxidant cosmetic products, we have developed a new non-invasive methodology for the evaluation of antioxidants cosmetics ingredients and finished products. METHODS: The effects of a pre-treatment on forearm skin with an antioxidant ingredient were investigated on 15 volunteers, in a double-blind randomised fashion. A non-invasive method was devised that comprises the collection of forehead SC layers of the pre-treated area and control and the next evaluation of skin antioxidant capacity (IAC-S) by a luminescence-based method. RESULTS: The results showed that the antioxidant preparation was able to increase, to a statistically significant extent (P<0.01), the IAC-S in comparison with the control area. The data were confirmed (P<0.05) by comparison with a method, previously developed by us, based on DermAnalyzer. CONCLUSIONS: In view of the simplicity and reliability of the method here presented, this new technique is proposed as a possible tool for the routine evaluation of in vivo efficacy of antioxidant functional ingredients and finished products.