Skin Microbiota: Setting up a Protocol to Evaluate a Correlation between the Microbial Flora and Skin Parameters

Squalene Peroxidation and Biophysical Parameters in Acne-Prone Skin: A Pilot "In Vivo" Study

Nowadays, acne vulgaris therapies are often unsuccessful. One of the responsible factors for the formation of comedones and inflammatory lesions could be the peroxidation of squalene, a hydrocarbon representing one of the major components of human sebum. This peroxidation is increased by solar irradiation. The purpose of this work was to set up an in vivo method for the extraction and quantification of squalene from acne skin and to correlate the results with biophysical skin parameters such as sebum amount, protein content and TEWL. Healthy volunteers were used as control. The results obtained demonstrated that acne-prone skin had a major quantity of squalene, and, in the stratum corneum area, its peroxide form is present. Moreover, Spearman's rank correlation showed a positive correlation between sebum content and peroxide squalene and between porphyrin intensity and peroxide squalene.

Effects of wearing masks during COVID-19 pandemic on the composition and diversity of skin bacteria and fungi in medical workers

Background

Although studies have shown that wearing masks can affect the skin microbiome, more detailed and comprehensive research on wearing masks needs to be further explored.

Objective

This study aimed to characterize the influence of mask wearing on the diversity and structural characteristics of the facial skin microbial community of medical staff during the COVID-19 pandemic by means of metagenomic sequencing (mNGS).

Methods

A total of 40 samples were taken by swabbing the cheek in the 2 × 2 cm2 area before and after wearing the masks. DNA was extracted for metagenomic sequencing.

Results

A statistically significant decrease was found in the α diversity between BN and AN groups and between B2 h and A2 h groups. BN and AN mean groups before and after 8 h of wearing the medical protective mask (N95), including 10 volunteers, respectively. B2 h and A2 h mean groups before and after 8 h of wearing masks, including 10 volunteers changing mask every 2 h, respectively. The β diversity was found to be statistically reduced between BS and AS groups (p = 0.025), BN and AN groups (p = 0.009), and B2 h and A2 h group (p = 0.042). The fungal beta diversity was significantly decreased in every group before and after wearing masks. The main bacteria on the face before and after wearing masks were Cutibacterium (68.02 and 71.73%). Among the fungi, Malassezia predominated the facial skin surface before and after wearing masks (35.81 and 39.63%, respectively).

Conclusion

Wearing different types of masks and changing masks according to different frequency will have different effects on the facial skin's microbiota.

Recent advances in in vitro skin-on-a-chip models for drug testing

INTRODUCTION

The skin is an organ that has the largest surface area and provides a barrier against external environment. While providing protection, it also interacts with other organs in the body and has implications in various diseases. Development of physiologically realistic in vitro models of the skin in the context of the whole body is important for studying these diseases, and will be a valuable tool for pharmaceutical, cosmetics, and food industry.

AREA COVERED

This article covers the basic background in skin structure, physiology, as well as drug metabolism in the skin, and dermatological diseases. We summarize various in vitro skin models currently available, and novel in vitro models based on organ-on-a-chip technology. We also explain the concept of multi-organ-on-a-chip and describe recent developments in this field aimed at recapitulating the interaction of the skin with other organs in the body.

EXPERT OPINION

Recent development in the organ-on-a-chip field has enabled the development of in vitro model systems that resemble human skin more closely than conventional models. In near future, we will be seeing various model systems that allow researchers to study complex diseases in a more mechanistic manner, which will help the development of new pharmaceuticals for such diseases.