Journal of cosmetic science最新文献

Our defense against solar ultraviolet (UV) damage to skin comprises endogenous mechanisms of DNA repair and pigmentation, and exogenous application of light-absorbing and reflecting sunscreens. Our most important endogenous defense, DNA repair, has been the focus of molecular and clinical research, and recent advances are summarized here. The approach of using microbial DNA repair enzymes to augment the natural DNA repair capacity of skin has gained acceptance in many commercial products, and clinical studies have supported their benefits.

Melanin, in people with naturally pigmented skins, offers a high level of photoprotection against the adverse molecular and clinical effects of solar ultraviolet radiation but, in contrast, has a modest inhibitory effect on vitamin D synthesis. Tanning in those with light skin offers relatively modest photoprotection. Sunscreens have the potential to offer high levels of protection in people who lack melanin. In theory, sunscreens can give protection comparable with that of deeply pigmented skin. This depends on the labeled sun protection factor (SPF) which in turn depends on how well the sunscreen is applied. In most cases, this will not achieve the desired SPF. The threshold dose for vitamin D synthesis is much lower than that for sunburn, such that vitamin D synthesis is still possible with sunscreen application.

Many outbreaks of Burkholderia cepacia complex (Bcc) infections are associated with contaminations in personal care products (PCPs). This study aimed to analyze a collection of Bcc isolates in PCPs and assess the susceptibility of preservatives, including dimethoxy dimethyl hydantoin (DMDMH), methylisothiazolinone-chloromethylisothiazolinone (MIT/cMIT), and methyl 4-hydroxybenzoate (MH). The Bcc isolates collected during the 3-year (2015-2017) study period were further examined by biochemical identification system, phylogenetic analysis based on recA nucleotide sequences, and multilocus sequence typing analysis. Preservatives susceptibility testing of Bcc bacteria were evaluated by minimum inhibitory concentration and minimum bactericidal concentration. A total of seven distinct sequence types (STs) were identified, which belonged to four different Bcc species: Burkholderia cenocepacia (ST621, ST258, and novel ST), Burkholderia lata (ST339 and ST336), Burkholderia contaminans (ST482), Burkholderia cepacia (ST922). For DMDMH and MH, the maximum permitted concentrations according to the safety specification of cosmetics (0.6% and 0.4%) were able to inhibit or kill all Bcc strains, but 40% of Bcc isolates could survive at higher than maximum permitted concentrations of MIT/cMIT (of a mixture in the ratio 3:1 of 5-chloro-2-methyl-4-isothiazolin-3-one and 2-methyl-4-isothiazolin-3-one). The PCPs contamination of Bcc strains should be given more attention by manufacturers because of its diversity in molecular epidemiology and its low susceptibility to preservatives such as MIT/cMIT.

Incorporating technologies such as 3D printers and the Internet of things (IoT) can improve the nail art industry by making it more efficient, and, most importantly, safer. It eliminates the need for physical shops such as nail salons. Nail art by 3D printing technology can achieve higher resolution and accuracy than before with conformal projection printing method (CPPM). The conventional method of painting nails manually leads to acute exposure to ultraviolet (UV) light that can contribute to minor health hazards. This research illustrates the benefits of using 3D printing for nail art. This study uses the IoT system, which can be stationed in a distinct location from the customer. The product on the nail is printed at least once and up to three times within 5 µm to achieve precise resolution through laser marking and CPPM, which can increase the accuracy by repeated projection to attain the required settling ratio. The correlation between the numbers of printed layers and different incident angles of the printing head on the conformal surface is discussed. The ratio of projected weight to the ideal weight for high-definition printing condition is illustrated, and comparison studies with conventional nail art techniques are conducted to validate the results.

Solvents play an essential role in the performance of ultraviolet (UV) filters. The goal of this study was to understand how the in vitro sun protection factor (SPF) and broad-spectrum protection of three organic UV filters (homosalate, ethylhexyl salicylate, and butyl methoxydibenzoylmethane) and a combination of these are influenced by solvents. Twenty-four solvents were selected based on the ingredient active gap for testing. Mixtures of UV filters and solvents were formulated, and in vitro SPF, wavelength of maximum absorbance, broad-spectrum protection, and spreadability were evaluated. Results indicate that in vitro SPF of organic sunscreens can be significantly enhanced by solvents. Relying on solubility data only was not found to be a good approach in this study. The most efficient solvents shared multiple similar structural characteristics, including ester bonds, conjugated structure, aromatic rings, and -CN groups; however, the absence of some of these structural elements did not necessarily prevent a solvent from being a booster. The wavelength of maximum absorbance was significantly shifted in the UVA range by most solvents, whereas minimal or no shift was observed in the UVB range. Results of this study provide practical information that can guide sunscreen formulators in selecting solvents for UV filters and making more effective sunscreens.

The internal ultrafine structure of human hair was explored with atomic force microscopy (AFM). Cross sections of hair were prepared by a proprietary technique that provided a smooth surface for effective imaging in contact-mode AFM. Investigations of virgin hair revealed structural details of cortical and cuticle cells consistent with previous transmission electron microscopy (TEM) studies, in addition to the identification of a boundary region surrounding macrofibrils of the cortex. The effects of bleaching and solvent extraction on the internal structure of hair were also investigated. In the cuticle cell, bleaching causes the most damage to the endocuticle and cell membrane complex, evident by erosion of these components. Similarly, bleaching results in crevices, cracks, and asperities in the cortex of hair. In addition, the cortical cell membrane complex appears compromised along with either lipid or protein structures at the outer boundaries of macrofibrils. In delipidated hair, most structural components of the fiber appear intact with the exception of an overall swollen nature of the various morphological components.

The aim of the study was to investigate the potential of a fucoxanthin concentrate prepared from Phaeodactylum tricornutum as a wrinkle care cosmetic agent. The concentrate (up to 25 µg/ml) did not affect the proliferation of human fibroblasts. In addition, the concentrate significantly increased procollagen synthesis in the fibroblasts at 12.5 and 25 µg/ml; however, it significantly decreased the expression of matrix metalloproteinase (MMP)-1, MMP-2, and MMP-9 at 25 µg/ml. In a follow-up study, a wrinkle care cream containing 0.03% of fucoxanthin concentrate was prepared and tested in women (aged 35-50 years, n = 21) for 8 weeks. The cream was applied twice daily. Safety assessment of the cream was carried out visually. In addition, interviews were conducted to investigate if adverse events such as erythema, edema, scaling, itching, stinging, burning, tightness, or prickling had occurred. No symptoms that threaten skin safety were reported. Evaluation of wrinkles around the eyes using the replica method showed a statistically significant decrease in wrinkles at week 8. Moreover, skin moisture and elasticity increased significantly from week 4. These results suggest that the fucoxanthin concentrate has no adverse effects on the skin and can be used as an active ingredient in wrinkle care cosmetics.

Five-aminolevulinic acid (5-ALA)-photodynamic therapy combined with infrared radiation is an effective and safe therapy for facial acne. Although there are various available agents for treating acne, therapies for resistant or severe strains have been limited. The aim of this study was to investigate the inhibitory efficacy of ALACELL synthesized by combining 5-ALA with Y-G-G-F-L peptide against Staphylococcus aureus, Bacillus cereus, Escherichia coli, and Yersinia enterocolitica, as well as Cutibacterium acnes. Furthermore, other effects of ALACELL on human skin cells, melanin formation, intracellular tyrosinase activity, and Ultra Violet B (UVB)-irradiated cell death were measured by treatment of ALACELL in vitro. ALACELL particularly showed a growth inhibitory effect on C. acnes and no inhibitory effect on the four bacteria strains. ALACELL reduced melanin formation and intracellular tyrosinase activity by α-melanin cell-stimulating hormone (α-MSH) in B16F10 cells, with no cytotoxicity. ALACELL also improved cell viability in UVB-irradiated HaCaT cells. The results of the experiment show that ALACELL exhibits more efficacy than 5-ALA against antimicrobial activity, melanin formation, intracellular tyrosinase activity, and UVB-irradiated cell death. Therefore, ALACELL is recommended as a candidate for clinical application in the treatment of acne and skin aging and will be further investigated to study the mode of action and in actual situations.

Striae distensae (SD) are linear dermal scars that arise from progressive stretching or tearing of the dermal layer. This study tests the safety and efficacy of a topical formulation of silicone-based scar cream containing selective synthetic recombinant human growth factors, hyaluronic acid, and vitamin C to improve overall appearance and texture of SD. Twenty-two subjects with SD alba were recruited and randomized to apply the topical formula to half of their SD laterally twice a day for 1 month. Patient surveys were obtained at 1 month for overall appearance, texture, and tolerability. Three-dimensional imaging was obtained at baseline and at 1 month and submitted to independent evaluators for grading on overall appearance. Subjects reported improved texture and appearance in 86.4% of SD. Subjects reported 100% of untreated SD to have no change in overall appearance or texture. 90.9% of subjects reported no tolerability issues. 9.1% of the treated group reported mild issues such as slight itching or redness the first day of application, which subsided in 2 days for all patients. Independent evaluators indicated improvement in 72.7% of SD in comparison to improvement in 36.3% of untreated SD. This study demonstrates that the investigated topical formulation is safe and effective to use for SD.