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.

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.

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).

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.