红光LED照射对自然老化SKH-1小鼠皮肤的影响OACSTPCD

Objective To investigate the effect of red light-emitting LED on the skin of intrinsically aged SKH-1 mice.Methods Twenty 12-month-old SKH-1 mice were selected and randomly divided into four groups,and each group was irradiated with light doses of 0 J/cm2,14.4 J/cm2,32.4 J/cm2 and 50.4 J/cm2 for 60 consecutive days using a red light LED instrument.On days 0,10,30 and 60,changes in skin appearance were recorded by taking gross photographs and dermoscopic photographs,and a skin aging rating scale was scored in terms of skin roughness,skin lines and skin firmness.Skin barrier function was measured by the water content of the stratum corneum(WCSC)and the transepidermal water loss(TEWL).Optical coherence tomography(OCT)was performed to detect the signal intensity in the dermis,and the structural changes in the skin of the four groups of mice were compared by HE staining and Masson staining.Results Compared to the 0 J/cm2 group,smoother and firmer skin was observed both visually and dermoscopically in the red light-treated mice,and and skin aging rating scale showed a significant improvement in skin roughness,skin wrinkles and skin firmness after red light irradiation.Red light irradiation not only improved skin appearance,but also significantly improved WCSC and TEWL.OCT results showed that red light irradiation increased the dermal thickness and dermal signal intensity.HE staining of skin tissues showed that red light irradiation increased epidermal thickness and maintained normal and tightly arranged cells in the epidermal layer.The Masson staining results showed that the dermal collagen content was significantly increased and collagen fibers were neatly arranged in the dermis of mice treated with red light.The improvement of the above indicators in the red LED irradiation group was enhanced with the increase of energy density,especially the effect of 50.4 J/cm2 group was the most significant,and the improvement lasted until the 60th day of illumination.Conclusion Red LED can significantly improve the skin appearance and skin barrier function of naturally aged SKH-1 mice,increase epidermal thickness and dermal collagen content,and maintain the tight arrangement of collagen fibers,providing a new experimental basis for the clinical application of LED light source in skin aging.