Benign lichenoid keratosis is one of the most common skin lesions that develop on the faces of middle-aged women. This study aimed to find an effective treatment method for benign lichenoid keratosis. A total of 49 patients, who had a positive diagnosis during 2010-2018, were enrolled in the study. An Investigator's Global Assessment of the lesion was done using the 5-point visual analog scale to evaluate treatment efficacy. After excluding subjects who did not have a follow-up photograph, 38 subjects were given an Investigator's Global Assessment score. Combination therapy using laser and a topical agent was useful in the management of benign lichenoid keratosis on the face. Ablative laser was effective for immediate improvement of the lesion, whereas non-ablative laser was also useful and showed several benefits over ablative laser. Optimal treatment should be decided after considering the patient's preference, compliance with treatment regimen, and skin type.

Polydeoxyribonucleotide (PDRN) is a mixture of deoxyribonucleotides. It serves as an anti-inflammatory and tissue-regenerating agent. The mitogen-activated protein kinase pathway modulates cell growth and collagen accumulation. It also regulates inflammation by suppressing the expression of proinflammatory cytokines. In the present study, it was attempted to elucidate the molecular mechanism of PDRN in skin healing by confirming the effects of PDRN treatment on skin keratinocytes and fibroblasts, and by assessing the levels of collagen and inflammatory cytokines regulated by the extracellular signal-regulated kinase (ERK) pathway. The potential effects of PDRN on skin regeneration were investigated. Fibroblast and keratinocyte proliferation and migration were analyzed using the water-soluble tetrazolium-8 and wound healing assays. The upregulation of collagen synthesis by PDRN-induced ERK activation was analyzed in fibroblasts with or without an ERK inhibitor. Inflammatory cytokine expression levels in keratinocytes were determined using reverse transcription-quantitative polymerase chain reaction. PDRN promoted the proliferation and migration of keratinocytes and fibroblasts. However, PDRN-induced ERK phosphorylation differed between keratinocytes and fibroblasts; PDRN increased ERK phosphorylation and collagen accumulation in fibroblasts, while it inhibited matrix metalloproteinase expression. By contrast, PDRN inhibited ERK phosphorylation in keratinocytes, and it decreased inflammatory cytokine expression levels. PDRN affects skin cell proliferation and migration, and collagen and inflammatory cytokine expression levels via ERK signaling. Overall, PDRN exerts a positive effect on skin regeneration, but the mechanism by which it promotes skin regeneration varies among different skin cell types.

Background Injectable poly‐l‐lactic acid (PLLA) carries the risk of nodule or microlump formation. Various methods including sonication have been tried to minimize these adverse effects of PLLA. Aims This study investigated the change in size, distribution, and properties of PLLA particles after sonication, and the duration of sonication needed to reach the ideal particle size. Methods and Materials Two indicators, the average size of PLLA particles and diameter at 90%, were measured at each timepoint: at 0, 10, 60, 120, and 240 minutes of sonication. The characteristics and particle shape were assessed at 0 and 240 minutes. Results The average particle size and the diameter at 90% decreased drastically until 10 minutes of sonication and then increased slightly at 60 minutes. After 60 minutes, the average size and the diameter at 90% gradually decreased over time and reached 42.2 μm and 75.7 μm, respectively, at 120 minutes. After 240 minutes of sonication, the average particle size was 35.9 μm, much smaller than the smallest proper size required (40 μm). Standard deviation decreased gradually over time, which means that a more even distribution was obtained. Crystalline remnants were significantly less left with 120 minutes sonication compared to those with 120 minutes hydration only. PLLA particles were more cracked at the center, and microcrystals were more loosely distributed at the periphery after 120 minutes sonication. Conclusion Sonication help reduce the average size of PLLA particles and achieve more even distribution. Therefore, we believe sonication may attribute to the safer use of PLLA.

Background Sensitive skin is a subjective cutaneous hyper‐reactivity that occurs in response to various innocuous stimuli. Keratinocytes have recently been shown to participate in sensory transduction by releasing many neuroactive molecules that bind to intra‐epidermal free nerve endings and modulate nociception. In the literature, the characterization of these interactions has been based on the co‐culture of keratinocyte and mammalian‐origin neuronal cell lines. In this study, we established an in vitro model based on a co‐culture of primary human keratinocytes and differentiated SH‐SY5Y cells, a human neuronal cell line. Methods Human epidermal keratinocytes and SH‐SY5Y cells were monocultured and co‐cultured. Changes in calcium influx, substance P, inflammatory cytokines, and neuropeptides between the monoculture and co‐culture groups treated with capsaicin only and capsaicin with transient receptor potential channel vanilloid subfamily member 1 (TRPV1) antagonist, trans‐4‐tert‐butylcyclohexanol (TTBC), together. In addition, the difference in stinging sensation was evaluated by applying it to the volunteers. Results When SH‐SY5Y cells were co‐cultured with keratinocytes, they had no significant effect on axonal development. Substance P was also released after capsaicin treatment and reduced by TTBC under co‐culture conditions. Moreover, the expression of inflammatory cytokines and neuropeptides was significantly increased in co‐cultured keratinocytes compared to that under monoculture conditions. In addition, the stinging sensation was significantly induced after the application of capsaicin in vivo and was relieved after the application of the TRPV1 antagonist. Conclusion We demonstrated that the novel co‐culture model is functionally valid through capsaicin and TRPV1 antagonist. We also confirmed that TTBC could be used for the treatment of sensitive skin through a co‐culture model and in vivo tests. This co‐culture model of keratinocytes and SH‐SY5Y cells may be useful in vitro alternatives for studying the close communication between keratinocytes and neuronal cells and for screening therapeutic drugs for sensitive skin.

Corni Fructus (CF) is a fruit of Cornus officinalis Sieb. et Zucc. and has been used as traditional oriental medicine. It has various functional qualities such as being antioxidative, anti-inflammatory, antidiabetic, antihyperglycemic, and immunity-regulating. In the current study, CF was extracted from two conventional extract solvents (distilled water (DW) and 70% ethanol) with/without high-speed homogenization (HSH) treatments. The extract was characterized by measuring the total polyphenol contents and antioxidant activities. The HSH treatment significantly improved the total polyphenol content (from 28.4±0.9 mg/mL to 35.5±0.9 mg/mL), ABTS (from 59.8±0.4% to 78.4±2.7%), and DPPH radical scavenging activities (from 50.8±1.4% to 59.7±2.8%) of the DW extract and showed a level similar to that of 70% ethanol extract. The CF extracts were further used to prepare functional jelly with gelatin and other components such as pectin, fructooligosaccharide, and citric acid. The jelly’s hardness, springiness, gumminess, and cohesiveness were characterized using a texture profile analysis (TPA).