Age-related changes in dermal fiber-like structures in facial cheeks

A serum containing vitamins C & E and a matrix-repair tripeptide reduces facial signs of aging as evidenced by Primos® analysis and frequently repeated auto-perception

Background

Allegations on the benefits of incorporating vitamin C, vitamin E, and combinations thereof in topical skincare formulations are mostly based on in vitro and ex vivo experiments and/or limited protocols of specific stress conditions (pollution, UV exposure, laser irradiation,…).

Objective

To evaluate the instrumentally measurable effects and quantitative consumer perceptions of a protective and reparative serum on a panel of volunteers under normal nonstressed conditions of use, employing FOITS technology and innovative self‐assessment methods.

Method

In an open‐label study women of ≥40 years with visible signs of photoaging applied a serum comprising l‐ascorbic acid USP (15% w/v), tocopheryl acetate USP, and 5 ppm palmitoyl tripeptide‐38 to the face once daily for 56 days. Skin roughness and isotropy changes were evaluated on days 0, 28, and 56, visual instrumental evaluation of skin‐tone parameters was assessed on days 0 and 56. Subjects completed self‐assessment questionnaires every third day of the trial period for radiance, homogeneity, and wrinkle appearance.

Results

Skin‐roughness parameters decreased significantly by 8%‐9% (P < .05) and subjects experienced a significant increase in skin isotropy (P < .05). Photographic analysis revealed significant improvements in skin tone, with a 9% decrease in redness and 8% increase in homogeneity (P < .0001 for both), in excellent agreement with subjects' perception of significant improvements of radiance, complexion, and wrinkles.

Conclusion

The study confirms statistically significant correlation between objectively measured and quantitative subjectively perceived benefits of the bespoke serum containing antioxidants and a matrix‐restoring peptide.

An assessment method for dermal structures using cross-polarized light imaging with a green light-emitting diode

BACKGROUND

Several experimental methods for evaluating dermal structures exist; however, most of these are not used in dermatology clinics because of cost and functional limitations.

OBJECTIVE

To propose a simple, non-invasive method for dermal structure evaluation using a green light-emitting diode (LED) with cross-polarized light (CPL) imaging and compare the quality of the images taken using either green or white LED.

MATERIALS AND METHODS

Skin specimens were taken from fifteen cadavers. Images were captured using CPL photography with a green or white LED. The Commission International d'Eclairage L*a*b* (CIELAB) values were calculated for each image. The skin specimens were processed and stained with Masson's trichrome to visualize collagen fibers with major image scattering. The images were histologically analyzed, and correlational and regression analyses were performed to determine the relationship between the L* values and histologic measurements.

RESULTS

The L* values for the green images were positively correlated with collagen fiber density, reticular collagen bundle diameter, and dermal thickness. They were effective for estimating dermal properties. The L* values for the white images were positively correlated with reticular collagen bundle diameter and dermal thickness. Correlational coefficients for white images were lower than those for green images. In regression analysis, green images showed a higher coefficient of determination (R² ) for predicting reticular collagen bundle diameter than white images (0.1128 vs. 0.0827).

CONCLUSION

Cross-polarized light imaging with a green LED is a simple, non-invasive method for evaluating dermal structures. The use of a green LED was also more effective for image analysis.

A simple morphometric analysis method for dermal microstructure using color thresholding and moments

BACKGROUND

Proper assessment of dermal collagen fibers by dermatologists and researchers is essential. Histologic evaluation methods have limitations. We present a simple method for measurement of collagen fibers in human skin using Masson's trichrome staining.

MATERIALS AND METHODS

Normal skin specimens from a cadaver were processed with Masson's trichrome, which can effectively stain collagen fibers blue with aniline dye. Optical photomicrographs of these slides were analyzed using ImageJ software. Color image processing, a histogram-based function of ImageJ for image segmentation, was performed with color moments thresholding technique. We selected blue areas by adjusting the blue channel to include specific values. The selected areas were highlighted and evaluated. We divided the image into layers of 0.09-mm² areas from the top to bottom of the dermis. Each area was cropped and evaluated.

RESULTS

Quantitative assessment yielded the quantitative size occupied by collagen fibers in an area of 0.09 mm² . Calculation of the percentage in each area can be used to determine the density of collagen fibers.

CONCLUSION

Measurements obtained with our method can be applied to research on dermal collagen fibers. We present a convenient quantitative assessment method for the dermal constituents in Masson's trichrome-stained slides.