Comparison of UVA protection afforded by high sun protection factor sunscreens

Eco-Friendly Superhydrophobic Composites with Thermostability, UV Resistance, and Coating Transparency

Despite the market demand for biofiber assemblies endowed with superhydrophobicity being huge, the current approaches to their production are complicated, time-consuming, and even pose a serious threat to the environment. Here, we report a simple surface treatment strategy to prepare environmentally friendly superhydrophobic biofiber composites. The obtained samples have certain UV resistance properties, which are mainly determined by the titanium dioxide (TiO₂) dosage. Additionally, the sample has excellent thermal stability, and the contact angle is maintained at 153.26° after heat treatment at 140 °C for 1 h. Quite encouragingly, thermal annealing of samples can transform translucent coatings into transparent structures and increase the tensile strength. The results also showed that this strategy could be integrated into the mass production process of other biofiber components as coating, such as coated paper, pulp boards, cotton gauzes, tissues, and so forth. Due to the facile preparation and environment-friendliness, this sustainable paper-based product can be used in diversified applications: packaging and storage of liquid food, protection of ancient books, UV- and rain-proof materials, and teaching demonstrations relevant to bionics, among others.

Ultraviolet a Radiation and The Need for Protection

Erythema is a readily visible, often painful, natural phenomenon indicative of prolonged cutaneous exposure to ultraviolet (UV) radiation in the UVB range. As a result, early sunscreens were designed to provide adequate protection from UVB radiation. However, the continuous rise in the melanoma incidence rate alludes to the existence of an established photocarcinogen from which we are not well protected. Recently, scientists have been evaluating the photodamaging effects caused by wavelengths other than UVB. They have presented evidence that suggests that UVA exposure poses a greater hazard than previously acknowledged. For this reason, more emphasis must be placed on the development of broad-spectrum sunscreens providing adequate UVA and UVB protection. Additionally, regular sunscreen application must be advocated, proactive sun-protective practices must be implemented, and greater public awareness of the harmful effects of UVA and UVB radiation must be improved on, with the hope of decreasing the rate of cutaneous malignant melanoma.

Mexoryl: Broad-Spectrum Ultraviolet a Photoprotection

The deleterious effects of long-wave (320–400 nm) ultraviolet (UV) radiation on human skin have been recognized for decades. Human exposure to UV radiation may induce skin pigmentation and sunburn, cutaneous connective tissue alterations (photoaging), immunosuppression, and the development of skin cancers. Public awareness campaigns on the need for photoprotection advocate the regular use of sunscreens. Consumer demand and an expanding knowledge of the adverse effects of UV exposure have fueled the continual development of novel sunscreen formulations. Two organic UV filters, terephthlylidene dicamphor sulphonic acid (Mexoryl SX, L'Oréal, Paris, France) and drometrizole trisiloxane (Mexoryl XL, L'Oréal), provide effective protection from UV irradiation and offer improved safety profiles in terms of protection from UVA radiation. This article details the photoprotective benefits of Mexoryl SX and Mexoryl XL.

Assessing the current market of sunscreen: a cross-sectional study of sunscreen availability in three metropolitan counties in the United States

Sunscreen use is recommended for the prevention of sunburn and skin cancer. Little is known regarding sunscreen availability in high versus low income communities. We analyzed sunscreen availability in three large metropolitan counties to determine the relationship between availability and community demographics. We included sun care products in all pharmacies and supermarkets open as of July 2013 in representative high and low income zip codes in Cook County, Illinois, Miami-Dade County, Florida, and San Diego County, California. We recorded the percentage of tanning oil, sunscreens with a sun protection factor (SPF) < 15, SPF > 15, physical sunscreens, spray sunscreens, mean price per ounce (PPO), and mean SPF. Of the total products assessed, 11.0% were tanning oils, with physical sunscreens accounting for only 3.4% of the available sunscreens and 46.2% of sunscreens being spray-on. A comparison between higher and lower income zip codes demonstrated a significantly increased percentage of sunscreens with SPF < 15 in high income zip codes. Lower income zip codes had higher percentages of sunscreens with SPF > 15 and higher PPO, even when taking into account SPF. Further studies of sunscreen usage patterns in different populations must take into account sunscreen availability and price, as these significantly differ based on the community demographic.

Photoprotection in contemporary dermatology and cosmetology: traditional issues and new data

The paper contains information of UVB and UVA influence on the various structures of the skin. Main principles of modern photoprotection, sunscreens as well as photoprotective role of clothes are discussed.

Suppression of PTEN transcription by UVA

Although ultraviolet A (UVA; 315-400 nm) has different physical and biological targets than ultraviolet B (UVB; 280-315 nm), the contribution of UVA to skin cancer susceptibility and its molecular basis remain largely unknown. Here we show that chronic UVA radiation suppresses phosphatase and tensin homolog (PTEN) expression at the mRNA level. Subchronic and acute UVA radiation also downregulated PTEN in normal human epidermal keratinocytes, skin culture, and mouse skin. At the molecular level, chronic UVA radiation decreased the transcriptional activity of the PTEN promoter in a methylation-independent manner, whereas it had no effect on the protein stability or mRNA stability of PTEN. In contrast, we found that UVA-induced activation of the Ras/ERK/AKT and NF-кB pathways plays an important role in UV-induced PTEN downregulation. Inhibiting extracellular signal-regulated kinases (ERK) or protein pinase B (AKT) increases PTEN expression. Our findings may provide unique insights into PTEN downregulation as a critical component of UVA's molecular impact during keratinocyte transformation.

Simple ultraviolet and high-performance liquid chromatography methods for the evaluation of sunscreen efficacy

BACKGROUND

To prevent DNA damage caused by the ultraviolet (UV) radiation of sunlight, sunscreens are commonly used to protect human skin. Current analysis of sunscreens' effectiveness is done through complicated procedures, including human exposure.

OBJECTIVE

We sought to design a simple system using thymidine-thymidine (TT) dinucleotides to analyze the effectiveness of sunscreens.

METHODS

We can directly analyze sunscreen effectiveness and the formation of TT photolesions simply by using UV spectrophotometry and high-performance liquid chromatography (HPLC). Efficient sunscreen has protective effects against UV irradiation damage.

RESULTS

We have developed a simple method using TT dinucleotide, UV, and HPLC for the analysis of sunscreen effectiveness. Our research indicates that the analytical results from UV are consistent with those of HPLC, which is used to monitor the formation of the TT photolesions. Moreover, both UV and HPLC analyses indicate that TT dinucleotides are better protected against UV damage, using the sunscreens with higher UVB sun protection factor (SPF) value, and that sunscreens with higher SPF lead to reduced photolesion formation. Our UV and HPLC analyses confirm the SPF grading of commercial sunscreens.

LIMITATIONS

In this experiment, only sunscreens were tested. The experiment, therefore, does not apply to other commercial products, such as cosmetic materials that claim UV protection as a secondary benefit.

CONCLUSION

In conclusion, we have established a simple strategy to analyze the effectiveness of sunscreens and the quality of these potential cancer-preventive products.

Cutaneous ultraviolet exposure and its relationship to the development of skin cancer

Skin cancer is becoming an increasingly important public health problem. Multiple studies have now demonstrated a relationship between ultraviolet exposure and increased risk of developing skin cancer. However, the specifics of that association are somewhat different for malignant melanoma, basal cell carcinoma, and squamous cell carcinoma. A better understanding of the mechanisms that allow cutaneous ultraviolet radiation to induce neoplasia will result in the development of better future sun-protection agents and strategies.

Sunscreen use in photodermatoses

Photodermatoses are relatively uncommon, but most dermatologists will have to diagnose and treat them at some point. This article highlights several photodermatoses, their common symptoms and possible. Unfortunately, sunscreens marketed in the United States do not presently contain agents that are effective against longer wavelengths. There are agents available in other countries that offer better protection. It is hypothesized that these products will soon be available in the United States. Until such time, clinicians should recommend agents with avobenzones, benzophenones, and the physical blockers titanium oxides. Two other agents, dihydroxyacetone and iron oxide, may also offer benefit in some of these patients.

Effective and safe use of lasers, light sources, and radiofrequency devices in the clinical management of Asian patients with selected dermatoses

BACKGROUND AND OBJECTIVES

The use of lasers, light sources, and radiofrequency devices in Asian patients differs from their use in Caucasians in several respects.

STUDY DESIGN/MATERIALS AND METHODS

The disease spectrum is very different with pigmentary disorders being more commonly encountered in Asian populations. Asian skin, with its higher epidermal melanin content, is more likely to develop adverse reactions, especially post-inflammatory hyperpigmentation (PIH), following treatment.

RESULTS AND CONCLUSIONS

The purpose of this article is to discuss the effective and safe use of lasers, light sources, and radiofrequency devices in the clinical management of Asian patients with selected dermatoses.