Non-invasive bioengineering methods for determining dry skin in Korean women

( Ji Hwoon Baek ),( Jae Sook Koh ),( Mi Young Lee ),( Han Jo Kim ),( Myoung Rae Kim ),( Hyun Jung Kim ),( Seung Hun Lee ) 한국피부장벽학회 2008 한국피부장벽학회지 Vol.10 No.2

The function of skin depends on the balance between the amount of moisture in stratum corneum and the lipid layer on the surface. The external factors such as humidity, ultraviolet rays, and temperature as well as the internal factors such as hormone can disturb such balance in skin. Moreover, frequent use of soap and surfactant, local stimulant such as alcohol or warm water can eliminate the lipid layer on the skin surface. When the balance is upset, a condition known as dry skin is caused, which is frequently observed among patients with atopic dermatitis or chronic cutaneous disorder. Environmental factors including cold and dry weather or frequent shower can also cause dry skin. A primary factor for dry skin includes insufficient moisture in stratum corneum, epidermal hyperproliferation, abnormal lipid synthesis, impaired skin barrier, etc. These usually affect one another aggravating the symptom. Clinical symptoms include itching, scaling, tightness, and redness. The unsatisfactory and unpleasant feeling as well as constant itchiness lowers the quality of life for those who have dry skin. Physiological characteristics of the skin vary with body sites, sex, age, and race. A number of studies using noninvasive bioengineering method are currently underway. Among previous researches regarding this, Marrakchi et al. measured blood flow in various sites of body in people with normal skin in different age group. By categorizing TEWL, stratum corneum hydration, sebum content, temperature, and pH according to the body sites and ages, they clarified the causal relationship among the physiological factors. Smalls et al. reported that the quantitative measurement of physiological factors of the skin using non-invasive methods is very effective in investigating the physiological changes in the structure of skin and its functions. Fischer et al. described the methods available for the assessment of dry skin. In this study, we conducted a self-evaluation, a clinical examination of the facial skin and non-invasive measurements for Korean women. The purpose of this study was to find the most useful parameters for classification of dry skin based on a clinical assessment and to suggest the reference values for categorizing dry skin in Korean women. In conclusion, the questionnaire survey found that 72% of the respondents had dry skin. Clinical assessment focusing on the cheek for skin roughness and scaling resulted in 6 subjects had very dry skin(5.83%), 29 had dry skin(28.15%), and 68 had normal skin with sufficient moisture(66.02%). We determined the values for categorization of dry skin using skin capacitance(r=0.550, p<0.01), dielectric constant(r=0.227, p<0.05), TEWL(r=-0.217, p<0.05), R5(r=0.320, p<0.01) and R7(r=0.341, p<0.01) parameters for mechanical property, and scaling(r=-0.437, p<0.01) which had relatively higher correlations with clinical assessment than other parameters. Using the classifications by clinical assessment, ``Very dry``, ``Dry`` and ``Nomal``, we obtained the reference values of each parameter for categorizing dry skin. Our study provided general information about the physiological characteristics of normal skin in Korean women and suggested the reference values for categorizing dry skin.

Air Pollutants on the Skin

( Ji Hwoon Baek ) 한국피부장벽학회 2020 한국피부장벽학회지 Vol.22 No.1

Pollution is defined as contamination of the earth’s environment with materials which interfere with human health, quality of life, or the natural functioning of the ecosystem. Whenever a prolonged and repetitive exposure to environmental stressors exceeds the skin’s normal defensive potential, there is a disturbance in the skin barrier function leading to the development of various skin diseases. Major air pollutants which affect the skin are solar ultraviolet radiation, polycyclic aromatic hydrocarbons, volatile organic compounds, nitrogen oxides, particulate matter, cigarette smoke, heavy metals and arsenic. Dermal uptake depends on the deposition of air pollutants on the skin surface, the composition of epidermal lipids, and the diffusion through the epidermis to the blood vessels.

Structure and Function of Tight Junctions in Skin

( Ji Hwoon Baek ) 한국피부장벽학회 2022 한국피부장벽학회지 Vol.24 No.1

The skin protects the body from excessive water loss and the invasion of harmful substances, such as chemicals and microbes. The stratum corneum, is recognized as a very important physical barrier. However, in recent years evidence emerged that tight junctions (TJ) might also play a crucial role in barrier function of the skin. TJ consist of transmembrane proteins, e.g. claudins, occludin and junctional adhesion molecules (JAM), and of plaque proteins, e.g. proteins ZO-1, ZO-2, ZO-3, MUPP-1 and symplekin. The molecular composition of TJ is highly complex and varies according to the cell type and degree of differentiation.

Air-Pollution as an Aggressor for Skin Barrier

( Ji Hwoon Baek ) 한국피부장벽학회 2020 한국피부장벽학회지 Vol.22 No.1

Jean Krutmann proposed that environmental factors which are part of the skin aging exposome fall into the following major categories: (i) sun radiations: ultraviolet radiation, visible light and infrared radiation, (ii) air pollution, (iii) tobacco smoke, (iv) nutrition, (v) a number of less well studied, miscellaneous factors, as well as (vi) cosmetic products. Pollution is defined as contamination of the earth’s environment with materials which interfere with human health, quality of life, or the natural functioning of the ecosystem. Whenever a prolonged and repetitive exposure to environmental stressors exceeds the skin’s normal defensive potential, there is a disturbance in the skin barrier function leading to the development of various skin diseases. Major air pollutants which affect the skin are solar ultraviolet radiation, polycyclic aromatic hydrocarbons, volatile organic compounds, nitrogen oxides, particulate matter, cigarette smoke, heavy metals and arsenic. Dermal uptake depends on the deposition of air pollutants on the skin surface, the composition of epidermal lipids, and the diffusion through the epidermis to the blood vessels. An epidemiological study of elderly Caucasian women indicated that exposure to traffic related PM contributes to skin aging. A correlation was also found between NO2 and pigment spot formation in women over 50 years of age in Germany. A very recent study indicates that exposure to increased ground levels of ozone may be associated with wrinkle formation in the face. Air pollutants can modify allergenic proteins affecting their interactions with the immune system.

Development of a New Test Method : Can Cosmetics Reduce Adhesion of PMs on the Skin?

백지훈 ( Ji Hwoon Baek ),( Han Jo Kim ),( Won Cheol Kim ),( Seong Reung Kim ),( Jae Sook Koh ) 한국피부장벽학회 2018 한국피부장벽학회지 Vol.20 No.2

PM stands for particulate matter, which is the term for a mixture of solid particles and liquid droplets found in the air. Some particles, such as dust, dirt, soot, or smoke, are large or dark enough to be seen with the naked eye. Others are so small they can only be detected using an electron microscope. PM10 : inhalable particles, with diameters that are generally 10 micrometers and smaller; and PM2.5 : fine inhalable particles, with diameters that are generally 2.5 micrometers and smaller. These particles come in many sizes and shapes and can be made up of hundreds of different chemicals. Most particles form in the atmosphere as a result of complex reactions of chemicals such as sulfur dioxide and nitrogen oxides, which are pollutants emitted from power plants, industries and automobiles. The size of particles is directly linked to their potential for causing health problems. Small particles less than 10 micrometers in diameter pose the greatest problems, because they can get deep into your lungs, and some may even get into your bloodstream. According to the National Institute of Environmental Research, the average composition of PM (PM10) in Seoul was 22% of organic carbon, 8% of elemental carbon, 22% of nitrate, 15% of sulfate, 15% of soil crust and 18% of others. PM2.5 showed relatively high composition ratio of sulfate and organic carbon compounds and low soil crust component compared to PM10. The purpose of this study was to develop test method which can prove reduction of pollutant attachment to the skin. To evaluate the PM anti-adhesion effect for cosmetic product, the subjects were selected on the basis of inclusion and exclusion criteria with healthy skin on forearm. The subjects who were males and females, ranging from 20 to 59 years were recruited in this study. The entire study was performed under the environmental conditions of specific relative temperature and humidity, controlled and maintained identically for each volunteer. The ambient temperature was maintained at 22±2℃ and the relative humidity was maintained in the range of 50±5%. PMs were spread into the chamber of which a forearm was on top of a rectangular open window. To quantify PMs on the test sites, PM adhesion area of forearm was taken by Folliscope^®(LeadM, Korea) and was analyzed using image-pro software(Media Cybernetics, USA). Or color parameters were taken by Color Reader CR-10^® (KONICA MINOLTA, INC., Japan). As a result of anti-adhesion test of PMs for cosmetic products, testing products significantly decreased quantity of the adhesive PMs on the skin compared with those of control.

Structure and function of tight junctions in skin

백지훈 ( Ji Hwoon Baek ) 한국피부장벽학회 2022 한국피부장벽학회지 Vol.24 No.1

The skin protects the body from excessive water loss and the invasion of harmful substances, such as chemicals and microbes. The stratum corneum, is recognized as a very important physical barrier. However, in recent years evidence emerged that tight junctions (TJ) might also play a crucial role in barrier function of the skin. TJ consist of transmembrane proteins, e.g. claudins, occludin and junctional adhesion molecules (JAM), and of plaque proteins, e.g. proteins ZO-1, ZO-2, ZO-3, MUPP-1 and symplekin. The molecular composition of TJ is highly complex and varies according to the cell type and degree of differentiation.

Anti-pollution cosmetics, are they really effective? Introducing a new test method

백지훈 ( Ji Hwoon Baek ) 대한피부과학회 2019 대한피부과학회 학술발표대회집 Vol.71 No.1

The basic of clinical trial: Non-invasive measurement of skin Mechanical property of skin: Elasticity, wrinkle, etc

백지훈 ( Ji Hwoon Baek ) 대한피부과학회 2017 대한피부과학회 학술발표대회집 Vol.69 No.2

An objective skin-type classification based on non-invasive biophysical parameters

( Ji-in Seo ),( Hye In Ham ),( Ji Hwoon Baek ),( Min Kyung Shin ) 한국피부장벽학회 2023 한국피부장벽학회지 Vol.25 No.2

Despite the invention of various non-invasive bioengineering tools in dermatology, skin type classification has been dependent on subjective evaluations. To design a novel skin type classification system based on biophysical parameters, and analyze the measurements made in the South Korean population. Measurements from 434 healthy Korean volunteers, aged 20 to 59 years, were extracted from the database of 2018 International Skin Characteristics Data Bank project. Parameters were analyzed by pH-meter^® PH900, tewameter^® TM300, corneometer^® CM825, sebumeter^® SM810, cutometer^® MPA580, spectrophotometer^® CM-2500d, PRIMOS^® lite, and Janus^®. We developed a new skin type classification system and applied measurements made from Korean subjects to determine the cut-off values. The classification is composed of five main categories (problematic, hydration, oiliness, elasticity, skin tone) and subcategories (erythema, roughness, enlarged pore, wrinkle, pigmentation). We present reference values using summary statistics (mean, standard, deviation, and percentile) for the eleven biophysical parameters based on gender and age groups (20s, 30s, 40s, and 50s). The proposed skin type classification enables non-invasive objective assessment of the skin. Additionally, the system will provide guidance in selecting problematic skin and assist education for skin care management.

Association between subjective and objective skin types

( Ji-in Seo ),( Hye In Ham ),( Ji Hwoon Baek ),( Min Kyung Shin ) 대한피부과학회 2021 대한피부과학회 학술발표대회집 Vol.73 No.1