A proposal of a standardized protocol to evaluate waterproof effect of eyeliner and mascara.

OBJECTIVE: Eye make-up products must have waterproofing properties to make sure that their colours do not smudge or wash away easily and remain intact despite water or perspiration. Until now, most research has focused on composition and components of make-up products and not on the level of waterproof. This study aimed to find methods to assess the waterproof degree of eyeliners and mascaras and determine the suitability of these methods. METHODS: Twenty female subjects were selected to test the waterproof of eyeliners, whereas 20 sets of false eyelashes were used to evaluate the waterproof of mascaras. For evaluating water-resistant properties, after test sites where eyeliners and mascaras were applied were immersed in water and natural drying for over 20 min (not artificial drying by drier etc.), L* value of the eyeliners applied on the forearm before and after the immersions, and intensity analysis values of mascaras applied on the false eyelashes were used to calculate the mean percentage waterproof removal ratio (%WPR). A product was hypothesized to be water resistant if the value for the mean %WPR was ≤50%. RESULTS: The non-waterproof eyeliners were not waterproof if their mean %WPR was >50%, whereas the waterproof eyeliners were waterproof if their mean %WPR was <50%. For mascaras, the mean %WPR was <50% after 1- to 2-h marks after immersion in water for both non-waterproof and waterproof products. After 3-4 h, the mean %WPR for the non-waterproof mascaras was >50%, rendering them not waterproof, whereas the mean %WPR for the waterproof mascaras was <50%, making them waterproof. CONCLUSION: We have evaluated the waterproof properties by analysing photographed images of the test sites where eyeliners and mascaras were applied. Results of the comparison between non-waterproof and waterproof eyeliners and mascaras, and the methods used, in particular, will be found useful in evaluating waterproof of other make-up products.

How much related to skin wrinkles between facial and body site? Age-related changes in skin wrinkle on the knee assessed by skin bioengineering techniques.

BACKGROUND/PURPOSE: Skin aging has been focused the wrinkle on the face than on the body, so most studies have been studied the change in Crow's feet for ages. Only little is known about the age-dependent changes of wrinkles on body sites. The aim of this study was to establish new grading criteria for severity of wrinkles on knees and to investigate the relationship of wrinkle severity with age- and site-dependent. METHODS: The skin on the knee of 38 healthy Korean female volunteers, divided into two groups young and old, were photographed. Standard photograph for body wrinkle was established (grade 0~7), and then visual assessment, skin wrinkle, and skin elasticity were evaluated on Crow's feet and the knee. We examined for any significant differences and the correlation of skin aging parameters with age and two different sites. RESULTS: Skin wrinkle severity with standard photograph and wrinkle parameters (Ra, Rmax, Rz, and Rv) had a significantly positive correlation with age-dependent on the knee (P < 0.001). Also, skin elastic parameters (R2, R5, R6, R7, and Q1) showed a significant negative correlation with age on the knee (P < 0.001). Skin wrinkle severity with standard photograph was highly correlated with all skin wrinkle parameters and skin elastic parameters (R2, R5, R7, and Q1) on the knee (P < 0.001). In addition, all the skin aging parameters on the knee were significantly correlated with Crow's feet (P < 0.01). Skin aging on the knee had the same tendency as the Crow's feet. CONCLUSIONS: This study has shown the new grading criteria of wrinkles on the knee. Skin wrinkle and elasticity on the knee are age-dependent related and aging on the knee is highly related to Crow's feet. Those parameters are using a quantitative method to evaluate body aging. Also, the knee is considered that it could be a suitable site to evaluate body aging.

Facial skin physiology recovery kinetics during 180 min post-washing with a cleanser.

BACKGROUND/PURPOSE: Facial cleansing is important to clean and exfoliate the skin while maintaining optimal physiologic function. However, there is insufficient data on the very early stage of skin change after applying soap or cleansing foam. We investigated the recovery kinetics of facial skin physiology during 180 min after exposure to the cleanser. METHODS: For the study, 22 Korean female subjects with normal and dry to oily skin type were recruited in this study. Study subjects were required to have face washing done within the 12 hours prior to visiting the research center, with only toner, lotion, or cream applied. The next day, the subjects visited the research center without face washing. We evaluated the skin hydration (Corneometer(®) CM 825), sebum (Sebumeter(®) SM 815), transepidermal water loss (Tewameter(®) TM 300), and pH (Skin-pH-Meter(®) PH 905) to define recovery kinetics of facial skin physiology during 180 min exposure post-cleansing. RESULTS: Skin hydration, sebum, and TEWL were significantly decreased at 20 min after washing, as compared to the baseline (P < 0.05). And skin hydration returned at 40 min, and skin sebum and TEWL returned at 120 min after washing. However, skin pH did not show significant differences at all times points. CONCLUSIONS: This study indicated that each of the skin parameters was restored at defined time points post-cleansing. Our result could be a useful reference to set the resting time in the estimation of skin bioengineering parameters.

A quantitative evaluation method of skin texture affected by skin ageing using replica images of the cheek.

OBJECTIVE: Skin texture is a fine structure of skin surface where the hill and furrow were crossed to form a star shape. This study was performed to establish a quantitative evaluation method of skin texture affected by skin ageing using replica images of the cheek. METHODS: After producing replicas of the left cheek areas of 80 female subjects, representative replica images were chosen to establish six-level facial skin texture index. Using this new index, skin texture of different-aged subjects was visually assessed by multiple examiners. The number of star configurations was also analysed using the same replica images. Other factors contributing to skin texture, such as skin elasticity, roughness, dermal density, moisture and gloss, were also analysed. RESULTS: The concordance between skin texture scores evaluated by three researchers was high (0.896), and there was a high correlation between skin texture score and age (r = 0.642). The number of star configurations showed high correlations with skin texture scores (r = 0.753) and with age (r = 0.776). Skin texture scores were highly correlated with skin roughness and dermal density, but not with moisture, gloss and elasticity. CONCLUSION: This study suggests that visual grading of skin texture score based on new facial skin texture index and quantification of star configurations will be useful in evaluating skin ageing.

Effects of p-coumaric acid on erythema and pigmentation of human skin exposed to ultraviolet radiation.

BACKGROUND: It has been recently recognized that p-coumaric acid (PCA) is a strong inhibitor of cellular melanogenesis. AIM: To evaluate the erythema-suppressive and skin-lightening effects of PCA after topical application to human skin. METHODS: The control and PCA cream products were applied twice daily to the skin of the forearm of 21 subjects before and after ultraviolet (UV) irradiation to determine whether they could prevent erythema formation and pigmentation. The cream products were also applied to different areas only after the induction of erythema or pigmentation to determine whether they could have a depigmenting effect. RESULTS: A 7-day application of control and PCA cream products before UV irradiation decreased UV-induced erythema formation by 31% and 77%, respectively, compared with untreated skin. When the PCA cream was applied after UV irradiation, its effects on skin colour or pigmentation were less remarkable. However, the melanin index was significantly decreased at the sites treated with PCA cream for 70 days compared with control sites, and the Individual Typology Angle (ITA°) value was increased significantly. Of the 21 subjects, 2 had mild adverse skin reactions to both the PCA and control creams. CONCLUSION: These results suggest that PCA cream can reduce UV-induced erythema formation and subsequent pigmentation in human skin.

Correlation between scaffold in vivo biocompatibility and in vitro cell compatibility using mesenchymal and mononuclear cell cultures.

The aim of this study was to compare the cell compatibility of silk and polyglycolic acid (PGA) scaffolds cultured in vitro with mesenchymal stem cells (MSCs) and peripheral blood mononuclear cells (PBMCs) to their biocompatibility in vivo following implantation. Scaffolds were knitted with silk or PGA thread and the average efficiency of cell attachment was 35 +/- 4% and 17 +/- 2% in the PGA and silk scaffold groups. Thus, the initial attachment of the MSC cells to the PGA scaffold was superior to the initial attachment of the cells on the silk scaffold. After 21 days in culture, the average cell density on the silk scaffold was 5.8 +/- 0.5 x 10(5) cells, and the average cell density of the PGA scaffolds was 6.34 +/- 0.5 x 10(5) cells. In addition, there was no cell cytoxicity observed with either scaffold. However, the immune response of in vitro cultured PBMCs was significantly higher with the PGA scaffold than with the silk scaffold. The proliferation of the PBMCs cultured on the PGA scaffold was two times greater than that of those cultured on the silk scaffold after 3 days of culture. In addition, the secretion of IL-1 by the PBMCs cultured on the PGA scaffold was superior to that of the PBMCs cultured on the silk scaffold. The secretion of IL-1beta and IFN-gamma was increased by about 50% when the PBMCs were cultured with the PGA scaffold. Silk and PGA scaffolds were also implanted subcutaneous in rats. Histological evaluation of the scaffold explants revealed the presence of monocytes and macrophages in PGA scaffold. The inflammatory tissue reaction was more conspicuous on the PGA scaffold than on the silk scaffold. These results suggest that the results of in vitro PBMC cultures were more closely related to the in vivo results of implantation than the results of in vitro MSC cultures.

Comparison between ultrasonography (Dermascan C version 3) and transparency profilometry (Skin Visiometer SV600).

BACKGROUND/PURPOSE: A recently developed method to estimate skin smoothness is the replica method, which may have the limitation of the roughness difference of actual skin due to the skin-replicating process. Therefore, observation of dermal layer change is very important. For this purpose, ultrasonic display equipment is generally used. The purpose of the present study was to investigate the correlation between skin roughness and dermal density in wrinkle evaluation. METHODS: We evaluated the crow's feet of 95 Korean females using mechanical assessments; Skin-Visiometer SV 600 and Dermascan C. Transparency profilometry (Skin Visiometer) use a very thin skin print, which allows parallel light to pass through and is analyzed immediately after production. High-frequency (20 MHz) ultrasonography (Dermascan C) enables non-invasive evaluation of skin thickness and echo density. RESULTS: We found a correlation between skin roughness and dermal density. Particularly, we found a significant correlation between skin roughness (R2) and dermal thickness. Also, we found a significant negative correlation between dermal density and dermal thickness (P<0.05). CONCLUSION: Therefore, the ultrasonography system may be considered a very useful method in wrinkle evaluation with the transparency profilometry. However, further study will be required.

Tissue engineered artificial skin composed of dermis and epidermis.

We made an artificial skin comprised of a stratified layer of keratinocytes and a dermal matrix with a type I collagen containing fibroblasts. In this work, we showed keratinocyte behavior under primary culture, gel contractions varying with concentration of collagen solution, and cell growth plots in the collagen gel. The optimum behavior of dermal equivalent could be obtained using 3.0 mg/ml collagen solution and attached gel culture. The attached gel culture had a jumping effect of growth factor on cell growth at the lag phase. To develop the artificial skin, 1x10(5) cells/cm2 of keratinocytes were cultured on the dermal equivalent at air-liquid interface. Finally, to overcome the problem that artificial skin of collagen gel was torn easily during suturing of grafting, we prepared histocompatible collagen mesh and attached the mesh to the bottom of the gel. Cultured artificial skins were successfully grafted onto rats.

Production and characterization of monoclonal antibodies directed to the kringle V and protease domains of human apolipoprotein(a).

Production and use of anti-apolipoprotein(a) monoclonal antibodies (MAbs) specific to single copy regions in the polymorphic lipoprotein(a) (Lp(a)) has been emphasized to be important for the standardization of measurements of the coronary heart disease risk factor, Lp(a). Here, mouse MAbs were prepared against the kringle V (V) and protease (P) domains of human apolipoprotein(a) (apo(a)), which domains are present in single copy in the apo(a) molecule. The cDNA for apo(a)VP was cloned from human liver cDNA library, and the V-P recombinant protein overexpressed in Escherichia coli was used as an antigen for the antibody production. Two antibodies named as MAb(a)20 and MAb(a)23 were finally produced, and they were characterized for their binding specificity and epitopes. The specificity of the antibodies was confirmed by an immunoblotting procedure and an enzyme-linked immunoassay (ELISA). It was shown that the antibodies had little, if any, cross-reactivity with human plasminogen, which is relatively abundant in human serum and is highly homologous (85%) with apo(a) in amino acid (aa) sequence. For epitope analysis, 3'-deletional series of apo(a)VP cDNA were constructed, and expression products of them were analyzed for the binding MAb(a)20 and MAb(a)23 do. It has been revealed that distinct epitopes were recognized by the two MAbs: MAb(a)23 (gamma2b, kappa) bound to the V region about 60 aa downstream from the N-terminal, and MAb(a)20 (gamma1, kappa) bound to the P region close to the C-terminal. A one step-sandwich ELISA system for Lp(a) was developed using MAb(a)20 as a capturing antibody and horseradish peroxidase (HRP)-coupled MAb(a)23 as a detecting antibody. The assay was found to be sensitive and useful for detecting Lp(a) in the range of 4-150 microg/dL (80 pM-3 nM).