Background. Tranexamic acid (TA) has emerged as a promising treatment for melasma without serious adverse effects. Ethosomes have been reported as the carriers for transdermal drug delivery systems to increase the amount of drug permeation through the skin. However, few studies of the local usage of TA‐loaded ethosomes exist. Objectives. To evaluate the efficacy of a mask containing 0.5% TA‐loaded ethosomes in the treatment of melasma in the Asian skin. Methods. In a double‐blind, placebo‐controlled, randomized, prospective study, 88 Asian participants with melasma were randomized 1 : 1 to two groups as follows: the TA or control. The TA group was treated with moisturizing masks with 0.5% TA‐loaded ethosomes, and the control was treated with moisturizing masks only. Masks were applied once daily for the first two weeks and once every other day for the third and fourth weeks. The primary outcome was measured by the modified melasma area and severity index (mMASI) and a visual analog scale (VAS) for vessels. The secondary outcomes were VAS for skin texture and satisfaction. Results. The reduction of VAS vessel scores at the end of treatment in the TA group was significantly greater than that in the control group (P < 0.001). The mMASI scores and skin texture scores decreased over time in both groups, but no significant differences were found between the two groups (P > 0.05). The score of participant satisfaction in the TA group was significantly higher than that in the control group (P < 0.01). Conclusions. Masks containing TA‐loaded ethosomes appear to be an effective treatment for Asian melasma in terms of angiogenesis and skin texture. It improves the pigmentation to some extent but has no significance. This trial is registered with ChiCTR1900024257.

Objective: This study aimed to chemically synthesize a homotrimeric collagen peptide, evaluate its safety, and assess its effectiveness in promoting collagen synthesis.Methods: A homotrimeric collagen peptide was synthesized and structurally characterized using circular dichroism and infrared spectroscopy. Thermal stability was analyzed by TG-DSC, and molecular weight and amino acid composition were determined. In vitro cytotoxicity testing assessed safety, while UV-induced photoaging experiments evaluated its effects on collagen and elastin synthesis. In vivo studies in BALB/c mice examined its impact on collagen content, skin structure, and angiogenesis.Results: The synthesized collagen peptide exhibited high purity (99.1%) and an amino acid composition of glycine, proline, and hydroxyproline in a balanced ratio (15:17:13). Structural analysis confirmed a stable triple-helical conformation similar to type I collagen with excellent thermal stability (Tm = 326.15°C). Cytotoxicity testing showed no adverse effects on cell viability. In vitro, the peptide significantly enhanced collagen and elastin synthesis in fibroblasts. In vivo, intradermal and subcutaneous injection increased collagen content, improved skin structure, and enhanced microvessel density.Conclusion: This study presents a chemically synthesized homotrimeric collagen peptide with superior purity, structural stability, and biological efficacy in promoting collagen synthesis. Compared to previous studies, this biomimetic material exhibits exceptional thermal stability (Tm = 326.15°C) and a well-balanced amino acid composition, enabling applications in cosmetics and medical devices requiring heat sterilization (e.g., autoclaving), as validated by our patented method (China Patent No. ZL202410309842.9).

Nowadays, laser is the mainstay treatment for cafe-au-lait macules (CALMs), but no systematic review has been published to demonstrate the overall efficacy and it’s still controversial which type of laser is optimal. Thus, we conduct the meta-analysis to evaluate the effectiveness and side effects of various types of lasers in treating CALMs. Original articles reporting the efficacy and side effects for CALMs in laser treatment were identified in PubMed, EMBASE, and Web of Science from 1983 to April 11, 2023. Using R software and the ‘meta’ package, meta-analysis was conducted for clearance and recurrence for evaluation of efficacy. And the occurrence of hypopigmentation and hyperpigmentation rate was pooled for safety evaluation. We used RoB2 and ROBINS-I tools to assess the risks of bias in RCT studies and non-RCT studies, respectively. The Grading of Recommendations, Assessment, Development and Evaluation system was used to assess the quality of the evidence. Nineteen studies involving 991 patients were included, which had a very low to moderate quality of evidence. The pooled 75% clearance rate was 43.3% (95% CI 31.8–54.7%, I² = 96%), 50% clearance rate was 75% (95% CI 62.2–85.9%, I² = 89%) and the recurrence rate was 13% (95% CI 3.2–26.5%, I² = 88%). The pooled hypopigmentation and hyperpigmentation rates were 1.2% (95% CI 0.3–2.1%, I² = 0%) and 1.2% (95% CI 0.3–2%, I² = 0%), respectively. Subgroup analysis revealed that QS-1064-nm Nd:YAG laser treatment not only achieved more than 75% clearance rate in 50.9% of patients (95% CI 26.9–74.4%, I² = 90%) but also resulted in the lowest hypopigmentation and hyperpigmentation rate of 0.5% (95% CI 0.0–2.5%, I² = 26%) and 0.4% (95% CI 0.0–2.5%, I² = 0%). To draw a conclusion, the laser treatment could reach an overall clearance rate of 50% for 75% of the patients with CALMs, for 43.3% of the patients, the clearance rate could reach 75%. When looking at different wavelength subgroups, QS-1064-nm Nd:YAG laser exhibited the best treatment capability. Laser of all the wavelength subgroups presented acceptable safety regarding of the low occurrence of side effects, namely, hypopigmentation and hyperpigmentation.

Melasma is a common acquired disorder of disfiguring hyperpigmentation and has attracted increasing attention in the field of medical aesthetics due to its high risk for recurrence and difficulty in treatment. Low-fluence Q-switched Nd: YAG 1064 nm (LFQSNY) laser is a commonly used phototherapy clinical for melasma at present, however, the mechanism underlying the photomanipulation remains unclear. Herein, this study aims to elucidate the potential mechanisms underlying the LFQSNY laser treatment. B16F10 murine melanoma cells were subjected to LFQSNY laser irradiation for evaluating melanin synthesis, tyrosinase activity, and melanogenic gene expression. RNA-seq and dual-luciferase reporter assays were utilized to dissect the interaction of DHX9 with TRIB3. C57BL/6J mice skin were irradiated for further assessments. Additionally, M1-polarized RAW264.7 macrophages were treated by laser to investigate inflammatory-mediator production and phagocytic capacity. LFQSNY laser irradiation significantly attenuated melanin production in cells via upregulating DHX9 and repressing TRIB3 through promoter binding, which emerged as a critical determinant of melanogenesis suppression. Furthermore, LFQSNY laser reduced the inflammatory factors and enhanced the phagocytic activity in macrophages, resulting in the anti-inflammatory activities and pigment-clearing. Our findings reveal that LFQSNY laser inhibits the melanogenesis of melanocytes and enhances the effect of anti-inflammation for improves pigment-clearance in melasma via a non-thermal photobiomodulation. The insights provide a mechanistic rationale for enhancing clinical efficacy of LFQSNY laser-therapy in melasma.