Professor Sungho Jeong's research demonstrating the selective and complete laser removal of darkly pigmented melanocytic tissue is the featured cover article for the Journal of Biophotonics
Professor Sungho Jeong's research demonstrating the selective and complete laser removal of darkly pigmented melanocytic tissue is the featured cover article for the Journal of Biophotonics
□ A research team led by Professor Sungho Jeong of the School of Mechanical Engineering at the Gwangju Institute of Science and Engineering (GIST • President Seung Hyeon Moon) has developed a technique to determine the concentration difference of major elements in melanocytic skin with respect to skin's pigmentation level by using laser induced plasma spectroscopy.
∘ Melanocytic nevus is a dark brown or black mole on the skin that has a higher density of melanocytes compared to the surrounding skin. Recently, removal procedures of these moles have increase for health and cosmetic reasons.
∘ Laser-assisted removal of melanocytic nevus is preferable to Mohs surgery, which removes the affected area with a surgical knife, because laser-assisted removal has a shorter recovery time and is better for scar-sensitive areas such as the face. However, when the size of the melanocytic nevus is large, a deep dermis is present and complete removal is impossible with a higher rate of recurrence after the procedure. Malignant tumors, such as melanoma, are accelerated by incomplete procedures.
∘ To help differentiate between normal skin tissue and melanocytic nevus, Professor Sungho Jeong's research team used laser induced breakdown spectroscopy (LIBS) as an in situ feedback tool for selective and complete laser removal of melanocytic skin tissue by using laser induced plasma spectroscopy to determine the concentration difference of major elements in melanocytic skin.
∘ In order to apply LIBS for the laser removal of melanocytes, Professor Sungho Jeong's research team analyzed biomarkers to distinguish between melanocytes and normal skin. Black silkie chicken was used in this experiment as the animal model because of its remarkable concentration of melanocytes in skin tissue near the pores than compared to surrounding skin tissue.
∘ The results showed higher LIBS signal intensities of Ca2+ and Mg2+ but lower inten-sities of Na+, Cl– and K+ in the perifollicular skin than in the extrafollicular skin, which demonstrated the feasibility to use LIBS as a reliable method to distinguish skin tissues with difference in pigmentation level. These results imply that Ca2+ has a positive correlation with skin pigmentation level while Na+, Cl–, and K+ have a negative correlation.
□ Professor Sungho Jeong said, "When the results of this study are applied to laser removal surgery, we can distinguish the boundary between melanocytic nevus and normal skin tissue, making it possible to selectively remove the nevus tissue while minimizing damage to the normal skin tissue. Melanoma pigmented lesions are known to have a much higher Ca2+ concentration than benign melanocytic nevus. Therefore, with real-time analysis of the Ca2+ in suspected lesions, we can prevent secondary skin damage caused by excessive laser procedures."
