No More Lying About Your Age
Scientists have developed a new technique that could provide a standardized, quantitative scale to rate the true ‘age’ of skin.
AsianScientist (Dec. 17, 2012) - Wrinkles, dryness, and a translucent and fragile appearance are hallmarks of old skin, caused by the natural aging of skin cells. But scientists do not have a standardized way to measure the extent of age damage in skin.
Now, a team of Taiwanese researchers has used a specialized microscope to peer harmlessly beneath the skin surface to measure natural age-related changes in the sizes of skin cells.
The results, which are published in the journal Biomedical Optics Express, can be used to study the general phenomenon of skin aging and may help provide an index for measuring the effectiveness of 'anti-aging' skin products.
In the study, led by Chi-Kuang Sun, a distinguished professor at National Taiwan University and chief director of the university's Molecular Imaging Center, the researchers evaluated 52 subjects ranging in age from 19 to 79 years old.
The researchers used a technique known as harmonic generation microscopy (HGM) to focus a brief burst of infrared laser light into the skin of the subjects' inner forearms, an area that is generally protected from sun damage, which accelerates natural aging.
The beam penetrated to a depth of about 300 millionths of a meter, or approximately where the epidermis (the upper layer of skin) and the dermis (the lower layer) meet.
In the procedure, a concentrated beam of photons is sent into the skin, and as the photons interact with the material, they generate "harmonics" - vibrations that are multiples of the original frequency, which can reveal different structures at very high resolution.
By scanning for reflected second and third harmonic photons, the researchers produced a high-resolution 3D map of the tissue that revealed structures within the skin cells.
Natural aging, the scanning showed, caused a significant increase in the overall size of cells known as basal keratinocytes – the most common cells in the outermost layer of skin – as well as in the sizes of their nuclei. However, other types of skin cells, known as granular cells, did not show a similar pattern.
Thus, says Sun, the relative changes in the two types of cells can serve as an index for scoring "intrinsic" skin aging - the aging of skin caused by programmed developmental or genetic factors.
"No one has ever seen through a person's skin to determine his or her age from their skin," says Sun. "Our finding serves as a potential index for skin age, and might also provide a test-bed for measuring the effectiveness of 'anti-aging' skin products," he said.
Source: Optical Society of America; Photo: GE Healthcare/Flickr/CC.
Disclaimer: This article does not necessarily reflect the views of AsianScientist or its staff.