New developments in sunscreens

Topical sunscreen application is one of the most important photoprotection tool to prevent sun damaging effects in human skin at the short and long term. Although its efficacy and cosmeticity have significantly improved in recent years, a better understanding of the biological and clinical effects of longer wavelength radiation, such as long ultraviolet A (UVA I) and blue light, has driven scientists and companies to search for effective and safe filters and substances to protect against these newly identified forms of radiation. New technologies have sought to imbue sunscreen with novel properties, such as the reduction of calorific radiation. Cutaneous penetration by sunscreens can also be reduced using hydrogels or nanocrystals that envelop the filters, or by binding filters to nanocarriers such as alginate microparticles, cyclodextrins, and methacrylate polymers. Finally, researchers have looked to nature as a source of healthier products, such as plant products (e.g., mycosporines, scytonemin, and various flavonoids) and even fungal and bacterial melanin, which could potentially be used as substitutes or enhancers of current filters

RELACIÓN ENTRE LA EXPOSICIÓN A LA RADIACIÓN SOLAR Y LA INFECCIÓN POR EL CORONAVIRUS SARS-CoV-2

Diferentes estudios asocian el déficit de vitamina D (VD) y la mayor gravedad y mortalidad por la COVID-19. La principal fuente de VD es la radiación solar. Algunos estudios apoyan que parece que hay una correlación inversa entre la exposición solar y la infección por coronavirus SARS-CoV-2. En España se ha observado una incidencia de la COVID-19 diferente entre distintos puntos de nuestra geografía lo que podría relacionarse con la radiación solar o la temperatura. El objetivo de este estudio es analizar la asociación entre el índice ultravioleta recibidos y las variaciones de temperatura en diferentes latitudesgeográficas de España y la incidencia, número de hospitalización y mortalidad por COVID-19.A través de un estudio observacional prospectivo se analizan los datos de incidencia de la COVID-19, temperatura máxima, mínima y UVI de 5 ciudades de España (San Sebastián, Zaragoza, Madrid, Málaga y Tenerife) desde enero de 2020 a febrero de 2021. A través del índice de correlación de Pearson se obtienen los resultados que objetivan una correlación inversa entre el UVI y los casos incidentes de COVID-19 estadísticamente significativa en todas las ciudades. La hospitalización y la mortalidad se correlacionaron inversamente con el UVI solo en las ciudades con mar y no en las del interior. En cuanto a la influencia de la temperatura, las correlaciones con las variables de COVID-19 fueron menos frecuentes, destacando la correlación inversa de las defunciones con las temperaturas máximas y mínimas en las ciudades del Sur, Málaga y Tenerife. No parece que el ingresar en la UCI guarde ninguna relación ni con el UVI ni con la temperatura.En conclusión, el UVI parece influir en la incidencia de casos de la pandemia por COVID19. Si esta acción se ejerce por su acción sintetizadora de vitamina D en la piel o es por otros mecanismos requiere futuras investigaciones.<br /

Prevalence and Comorbidity of Atopic Dermatitis in Children: A Large-Scale Population Study Based on Real-World Data

This study aimed at exploring atopic dermatitis (AD) prevalence in children and exhaustively analyzing their comorbidity. We conducted a descriptive analysis of their socio-demographic and comorbidity characteristics in the EpiChron Cohort (Aragon, Spain). Adjusted odds ratios (OR) were calculated for each comorbidity using logistic regression models. In total, 33, 591 children had a diagnosis of AD, resulting in an overall prevalence of 15.5%. AD prevalence was higher in girls compared to boys, in 3-9-year-olds compared to children of other ages, and in Spanish children compared to those of other nationalities. Multimorbidity was present in 43% of children, with the most frequent chronic comorbidities being asthma (13.1%), psychosocial disorders (7.9%), and visual impairment (7.8%). Many diseases were, regardless of their prevalence, statistically associated with AD. The strongest associations (odds ratio (OR) (95% confidence interval (CI))) were found in asthma (2.10 (2.02-2.17)), allergic rhinitis (2.00 (1.91-2.10)), and irritable bowel syndrome (1.90 (1.56-2.31)). A better understanding of the array of comorbidities associated with AD in children might help improve their clinical management. Future longitudinal studies are encouraged to shed light on the potential underlying pathophysiological mechanisms involved in the identified associations

Biomarkers of basal cell carcinoma resistance to methyl-aminolevulinate photodynamic therapy

This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited. Background Methyl-aminolevulinate photodynamic therapy (MAL-PDT) is an excellent option for the treatment of basal cell carcinoma (BCC). However, up to 25% of cases are resistant to this treatment modality. Objective The aim of this study was to identify potential biomarkers of BCC response to MAL-PDT. Material and methods Clinical, histological, and immunohistochemical (p53, Ki-67, CD-31, COX2, β-catenin, EGFR, and survivin) variables were analyzed in a retrospective study of consecutive BCC patients treated with MAL-PDT at the San Jorge Hospital, Huesca, Spain between January 2006 and December 2015. To deepen on these markers, the effects on p53 and cyclin D1 expression, in vitro response to MAL-PDT of 2 murine BCC cell lines (ASZ and BSZ), was also evaluated. Results The retrospective study examined the response to MAL-PDT of 390 BCCs from 182 patients. The overall clinical response rate was 82.8%, with a mean follow-up time of 35.96 months (SD = 23.46). Immunohistochemistry revealed positive p53 in 84.6% of responders but only 15.4% of nonresponsive tumors (p = 0.011). Tumors with increased peripheral palisading of basal cell islands to immunostaining β-catenin responded poorly to PDT (p = 0.01). In line with our findings in patients, in vitro studies revealed a better response to PDT in the p53-positive ASZ cell line than the p53-negative BSZ cell line (p&lt;0.01). Multivariate analysis revealed that the following variables were significantly associated with response to PDT: age, nBCC, presence of peritumoral inflammatory infiltrate, and p53 immunopositivity. Patients with positive p53 immunostaining were 68.54 times more likely to achieve cure than p53-negative patients (CI95% 2.94–159.8) Conclusion Our finding suggest that certain clinicopathological and immunohistochemical variables, particularly p53 expression, may serve as indicators of BCC response to MAL-PDT, and thus facilitate the selection of patients who are most likely to benefit from this therapyThis project received support from the Instituto de Salud Carlos III and Fondos Feder Europeos, MINECO (FIS PI15/00974). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscrip

Correlation between UV Index, Temperature and Humidity with Respect to Incidence and Severity of COVID 19 in Spain

Background: Various studies support the inverse correlation between solar exposure and Coronavirus SARS-CoV-2 infection. In Spain, from the Canary Islands to the northern part of the country, the global incidence of COVID-19 is different depending on latitude, which could be related to different meteorological conditions such as temperature, humidity, and ultraviolet index (UVI). The objective of the present work was to analyze the association between UVI, other relevant environmental factors such as temperature and humidity, and the incidence, severity, and mortality of COVID-19 at different latitudes in Spain. Methods: An observational prospective study was conducted, recording the numbers of new cases, hospitalizations, patients in critical units, mortality rates, and annual variations related to UVI, temperature, and humidity in five different provinces of Spain from January 2020 to February 2021. Results: Statistically significant inverse correlations (Spearman coefficients) were observed between UVI, temperature, annual changes, and the incidence of COVID-19 cases at almost all latitudes. Conclusion: Higher ultraviolet radiation levels and mean temperatures could contribute to reducing COVID-19 incidence, hospitalizations, and mortalityPartial funding for open access charge: Universidad de Málag

Influence of Serum Vitamin D Level in the Response of Actinic Keratosis to Photodynamic Therapy with Methylaminolevulinate

In mouse models of squamous cell carcinoma, pre-treatment with calcitriol prior to photodynamic therapy with aminolevulinic acid (ALA) enhances tumor cell death. We have evaluated the association between vitamin D status and the response of actinic keratoses to photodynamic therapy with methylaminolevulinate. Twenty-five patients with actinic keratoses on the head received one session of photodynamic therapy with methylaminolevulinate. Biopsies were taken at baseline and six weeks after treatment. Immuno-histochemical staining was performed for VDR, P53, Ki67 and beta-catenin. Basal serum 25(OH)D levels were determined. Cases with a positive histological response to treatment had significantly higher serum 25(OH)D levels (26.96 (SD 7.49) ngr/mL) than those without response (18.60 (SE 7.49) ngr/mL) (p = 0.05). Patients with a complete clinical response displayed lower basal VDR expression (35.71% (SD 19.88)) than partial responders (62.78% (SD 16.735)), (p = 0.002). Our results support a relationship between vitamin D status and the response of actinic keratoses to photodynamic therapy with methylaminolevulinate

Photodynamic Therapy Combined with Antibiotics or Antifungals against Microorganisms That Cause Skin and Soft Tissue Infections: A Planktonic and Biofilm Approach to Overcome Resistances

The present review covers combination approaches of antimicrobial photodynamic therapy (aPDT) plus antibiotics or antifungals to attack bacteria and fungi in vitro (both planktonic and biofilm forms) focused on those microorganisms that cause infections in skin and soft tissues. The combination can prevent failure in the fight against these microorganisms: antimicrobial drugs can increase the susceptibility of microorganisms to aPDT and prevent the possibility of regrowth of those that were not inactivated during the irradiation; meanwhile, aPDT is effective regardless of the resistance pattern of the strain and their use does not contribute to the selection of antimicrobial resistance. Additive or synergistic antimicrobial effects in vitro are evaluated and the best combinations are presented. The use of combined treatment of aPDT with antimicrobials could help overcome the difficulty of fighting high level of resistance microorganisms and, as it is a multi-target approach, it could make the selection of resistant microorganisms more difficult

Environmental Stressors on Skin Aging. Mechanistic Insights

The skin is the main barrier that protects us against environmental stressors (physical, chemical, and biological). These stressors, combined with internal factors, are responsible for cutaneous aging. Furthermore, they negatively affect the skin and increase the risk of cutaneous diseases, particularly skin cancer. This review addresses the impact of environmental stressors on skin aging, especially those related to general and specific external factors (lifestyle, occupation, pollutants, and light exposure). More specifically, we have evaluated ambient air pollution, household air pollutants from non-combustion sources, and exposure to light (ultraviolet radiation and blue and red light). We approach the molecular pathways involved in skin aging and pathology as a result of exposure to these external environmental stressors. Finally, we reflect on how components of environmental stress can interact with ultraviolet radiation to cause cell damage and the critical importance of knowing the mechanisms to develop new therapies to maintain the skin without damage in old age and to repair its diseasesThis research was funded by Spanish grants from Instituto de Salud Carlos III MINECO and Feder Funds (FIS: PI15/00974, PI18/00708, and PI18/00858

Modeling an optimal 3D Skin-on-Chip within microfluidic devices for pharmacological studies

Preclinical research remains hampered by an inadequate representation of human tissue environments which results in inaccurate predictions of a drug candidate''s effects and target''s suitability. While human 2D and 3D cell cultures and organoids have been extensively improved to mimic the precise structure and function of human tissues, major challenges persist since only few of these models adequately represent the complexity of human tissues. The development of skin-on-chip technology has allowed the transition from static 3D cultures to dynamic 3D cultures resembling human physiology. The integration of vasculature, immune system, or the resident microbiome in the next generation of SoC, with continuous detection of changes in metabolism, would potentially overcome the current limitations, providing reliable and robust results and mimicking the complex human skin. This review aims to provide an overview of the biological skin constituents and mechanical requirements that should be incorporated in a human skin-on-chip, permitting pharmacological, toxicological, and cosmetic tests closer to reality