Daily Cosmetic Research Analysis

BACKGROUND: Hyaluronic acid (HA) is extensively employed in various fields such as medicine, cosmetics, food, etc. The molecular weight (MW) of HA is crucial for its biological functions. Streptococcus zooepidemicus, a prominent HA industrial producer, naturally synthetizes HA with high MW. Currently, few effective approaches exist for the direct and precise regulation of HA MW through a one-step fermentation process, and S. zooepidemicus lacks metabolic regulatory elements with varying intensities. The ratio of HA's precursors, UDP-N-acetylglucosamine (UDP-GlcNAc) and UDP-glucuronic acid (UDP-GlcA), is critical for the extension and release of HA. An imbalance in the precursor proportions for HA synthesis leads to a significant decrease in HA MW, indicating that controlling the precursor ratio may serve as a potential method for regulating HA MW. RESULTS: In this study, the type and concentration of carbon sources were manipulated to disrupt the balance of precursor supply. Based on the results, it was speculated that the transcription level of hasE, which may connect the two HA synthesis precursors, is positively correlated with HA MW. Consequently, an endogenous expression component library for S. zooepidemicus was constructed, comprising 32 constitutive and 4 inducible expression elements. The expression of hasE was subsequently regulated in strain SE0 (S12 ΔhasE) using two constitutive promoters of differing strengths. The recombinant strain SE1, in which hasE was controlled by the stronger promoter PR31, produced HA with a MW of 1.96 MDa. In contrast, SE2, utilizing the weaker promoter PR22, synthesized shorter HA with a MW of 1.63 MDa, thereby verifying the hypothesis. Finally, to precisely regulate HA MW according to specific demands, an efficient sucrose-induced expression system was screened and employed to control the transcription level of hasE, obtaining recombinant strain SE3. When induced with sucrose concentrations of 3, 5-10 g/L, the HA MW of SE3 reached 0.78 to 1.77 MDa, respectively. CONCLUSIONS: Studies on regulating the balance of the HA precursor substances indicate that an oversupply of either UDP-GlcNAc or UDP-GlcUA can reduce HA MW. The hasE gene serves as a crucial regulator for maintaining this balance. Precise regulation of hasE transcription was achieved through an efficient inducible expression system, enabling the customized production of HA with specific MW. The HA MW of strain SE3 can be accurately manipulated by adjusting sucrose concentration, establishing a novel strategy for customized HA fermentation.

Marine ecosystems, particularly coastal areas, are becoming increasingly vulnerable to pollution from human activities. Persistent organic pollutants and contaminants of emerging concern (CECs) are recognized as significant threats to both human and environmental health. Our study aimed to identify the molecules present in the seawater of two bathing areas in the Western Mediterranean Sea. Polar Organic Chemical Integrative Samplers were employed for passive sampling of UV filters and other contaminants in the seawater. The concentrations of UV filters bemotrizinol (BEMT), benzophenone-3 (BP3), diethylamino hydroxybenzoyl hexyl benzoate (DHHB), octyl triazone (ET), and octocrylene (OC) were measured at these bathing sites during the summer of 2022. In addition, non-targeted chemical analysis was used to complement the list of pollutants in the sampling areas, leading to the identification of 53 contaminants and three natural products. Dodecyltrimethylammonium (DTA) and tetradecyltrimethylammonium (TTA) ions, 1,3-diphenylguanidine (DPG), N,N-diethyl-m-toluamide (DEET), and crystal violet (CV) were successfully quantified. Risk assessments showed that DEET, DPG, and BP3 present low environmental risks at the detected concentrations, while CV, DTA, and TTA pose medium to high risks, warranting further investigation. OC was found to pose a significant risk to marine biodiversity, as its environmental concentrations exceeded predicted no-effect concentration values. Overall, this study highlights the complexity of environmental pollution in coastal bathing areas and underscores the urgent need for comprehensive risk assessments to safeguard marine life and public health.

BACKGROUND: The use of robotic-assisted nipple-sparing mastectomy (R-NSM) with immediate direct-to-implant (DTI) reconstruction in treatment of breast cancer has been a controversial topic. The adoption of robotic surgery in breast cancer treatment has gained traction globally due to its minimally invasive nature, potential for improved cosmetic outcomes and better intraoperative visualization. This study provides insights on safety and feasibility robotic mastectomy at one of the largest centers in Asia. METHODS: This retrospective study included patients who underwent robotic nipple-sparing mastectomy (R-NSM) with immediate direct-to-implant (DTI) reconstruction from April 2018 to September 2024. Our endpoints were mainly focused on perioperative outcomes, patient satisfaction, and oncologic outcomes. RESULTS: A total of 266 procedures were included in our series, with 233 patients undergoing unilateral R-NSM with either DTI reconstruction or a tissue expander, and 33 patients underwent surgery on both breasts. Postoperative complications were recorded in 11 patients (4.14 %). The median follow-up of this study is 37.2 ± 23.3 months. Locoregional recurrence (LRR) was observed in 6 patients (2.5 %), with isolated skin recurrence being the most common. Distant metastasis was observed in 9 patients (3.86 %). The 3-year overall survival rate was 98.3 %. CONCLUSION: Robotic NSM is a safe and feasible novel minimal invasive surgical approach for breast cancer surgery, providing both excellent cosmetic results and oncological outcomes that are noninferior to conventional or endoscopic approaches.