Delamination-Assisted Ultrafast Wrinkle Formation in a Freestanding Film

Freestanding films provide a versatile platform for materials engineering thanks to additional structural motifs not found in films with a substrate. A ubiquitous example is wrinkles, yet little is known about how they can develop over as fast as a few picoseconds due to a lack of experimental probes to visualize their dynamics in real time on the nanoscopic scale. Here, we use time-resolved electron diffraction to directly observe light-activated wrinkling formation in freestanding La2/3Ca1/3MnO3 films. Via a "lock-in" analysis of oscillations in the diffraction peak position, intensity, and width, we quantitatively reconstructed how wrinkles develop on the time scale of lattice vibration. Contrary to the common assumption of fixed boundary conditions, we found that wrinkle development is associated with ultrafast delamination at the film boundaries. Our work provides a generic protocol to quantify wrinkling dynamics in freestanding films and highlights the importance of the film-substrate interaction in determining the properties of freestanding structures.

Mechanics of pressurized planar hyperelastic membranes

The paper examines the mechanics of inflation of incompressible planar hyperelastic membranes that are rigidly fixed at their boundary and subjected to a uniform pressure. Strain energy functions characterized by the neo-Hookean, Mooney-Rivlin and the Ogden forms are used. Fixity is provided along either circular or elliptical boundaries. The computational results indicate that the strain energy function has a significant influence on the pressure versus inflated volume response of the deformed membrane. When the strain energy function corresponds to a Mooney-Rivlin form, the circular membrane displays no tendency to develop any instability. The equivalent circular membranes composed of both the neo-Hookean and Ogden-type strain energy functions developed an initial 'Wrinkling Instability'. For planar membranes with an elliptical planform, the wrinkling instability is more pronounced; membranes composed of hyperelastic materials with a Mooney-Rivlin form of the strain energy function continue to deform without the development of an initial instability point, whereas membranes composed of both the neo-Hookean and Ogden materials exhibit wrinkling behaviour at critical locations at the interior of the fixed boundary region. The dependency of the strain energy function on the second invariant of the Cauchy-Green strain tensor has an influence in the suppression of hyperelastic effects. This article is part of the theme issue 'The Ogden model of rubber mechanics: Fifty years of impact on nonlinear elasticity'.

Anti-Photoaging Activity of Scutellaria barbata D. Don (Family Lamiaceae) on Ultraviolet B-Irradiated NIH-3T3 Skin Fibroblast and SKH-1 Hairless Mouse

We investigated whether Scutellaria barbata D. Don (Family Lamiaceae) (SBD), a traditional medicine used for heat clearing and detoxification, possesses antiphotoaging properties. Pretreatment of NIH-3T3 skin fibroblast cells with non-toxicological levels of water extract of SBD (WESBD) and ethanol extract of SBD (EESBD) restored the expression of procollagen type-1 (COL1A1), matrix metalloproteinase-1a (MMP-1a), interleukin-6 (IL-6), interleukin-8 (IL-8), and monocyte chemotactic protein-3 (MCP-3) genes following abnormal expression induced by ultraviolet B (UVB) irradiation. WESBD/EESBD administration to the dorsal skin area of hairless mice significantly (p < 0.05) inhibited UVB-induced wrinkle formation and epidermal thickness. The WESBD and EESBD treatments also restored the dermal collagen content, which was decreased by the UVB treatment, and normal COL1A1 and MMP-1a expression. Interestingly, both the WESBD and EESBD pretreatments significantly attenuated UVB-induced phosphorylation of protein kinase B (AKT) but not that of mitogen-activated protein kinases (MAPKs). This finding indicates that the antiphotoaging effects of WESBD and EESBD may be related to attenuation of UVB-induced overactivation of AKT phosphorylation. High performance liquid chromatography (HPLC) and mass spectrometry analysis revealed that isorhamentin and scutebarbatine I were major single components of EESBD. These results suggest that WESBD and EESBD may have potential in development as antiphotoaging agents.

In Vitro Anti-Photoaging and Skin Protective Effects of Licania macrocarpa Cuatrec Methanol Extract

The Licania genus has been used in the treatment of dysentery, diabetes, inflammation, and diarrhea in South America. Of these plants, the strong anti-inflammatory activity of Licania macrocarpa Cuatrec (Chrysobalanaceae) has been reported previously. However, the beneficial activities of this plant on skin health have remained unclear. This study explores the protective activity of a methanol extract (50-100 μg/mL) in the aerial parts of L. macrocarpa Cuatrec (Lm-ME) and its mechanism, in terms of its moisturizing/hydration factors, skin wrinkles, UV radiation-induced cell damage, and radical generation (using RT/real-time PCR, carbazole assays, flowcytometry, DPPH/ABTS, and immunoblotting analysis). The anti-pigmentation role of Lm-ME was also tested by measuring levels of melanin, melanogenesis-related genes, and pigmentation-regulatory proteins. Lm-ME decreased UVB-irradiated death in HaCaT cells by suppressing apoptosis and inhibited matrix metalloproteinases 1/2 (MMP1/2) expression by enhancing the activity of extracellular signal-regulated kinase (ERK), c-Jun N-terminal kinase (JNK), and p38. It was confirmed that Lm-ME displayed strong antioxidative activity. Lm-ME upregulated the expression of hyaluronan synthases-2/3 (HAS-2/3) and transglutaminase-1 (TGM-1), as well as secreted levels of hyaluronic acid (HA) via p38 and JNK activation. This extract also significantly inhibited the production of hyaluronidase (Hyal)-1, -2, and -4. Lm-ME reduced the melanin expression of microphthalmia-associated transcription factor (MITF), tyrosinase, and tyrosinase-related protein-1/2 (TYRP-1/2) in α-melanocyte-stimulating hormone (α-MSH)-treated B16F10 cells via the reduction of cAMP response element-binding protein (CREB) and p38 activation. These results suggest that Lm-ME plays a role in skin protection through antioxidative, moisturizing, cytoprotective, and skin-lightening properties, and may become a new and promising cosmetic product beneficial for the skin.

The Origin of the Sheet Size Predicament in Graphene Macroscopic Papers

The larger size of graphene sheets should intuitively generate higher overall properties of their macroscopic materials. However, this intuitive notion still remains ambiguous. Here, we uncover that the wrinkle formation causes the counterintuitive size predicament of graphene sheets in their macroscopic materials. In the model of graphene oxide assembled papers, we reveal that the giant size of graphene oxide sheets aggravates the formation of larger wrinkles and more microvoids, causing the negative size effect in mechanical strength. A major microscopic origin of the size predicament is the skin wrinkling in the drying process, and the wrinkling behavior follows a general rule of deformation of an elastic thin plate. We use a wrinkle-engineering strategy to depress the spontaneously formed large wrinkles and succeed in the resolution of the size predicament. After wrinkle modulation, an authentically positive size effect reversely appears in which giant graphene sheets generate ultrahigh mechanical strength and superior functionalities of graphene papers. The origin of the size predicament reminds us of the hidden importance of modulating wrinkles for graphene macroscopic materials and provides a guidance of wrinkle engineering for graphene materials with advanced performances.

Rose Petal Extract (Rosa gallica) Exerts Skin Whitening and Anti-Skin Wrinkle Effects

We sought to investigate the effect of extracts from Rosa gallica petals (RPE) on skin whitening and anti-wrinkle activity. Tyrosinase activity was attenuated by RPE treatment, concomitant with the reduction of melanin accumulation in human B16F10 melanoma. Treatment of the facial skin of volunteers in a clinical trial with an RPE-containing formulation enhanced skin brightness (L* value) significantly. The underlying mechanism responsible was determined to be associated with mitogen-activated protein kinase (MAPK) activation. In addition, RPE exhibited anti-wrinkle formation activity of human dermal fibroblasts by suppressing matrix metalloproteinase (MMP)-1 level. In vivo study, RPE also inhibited solar ultraviolet-stimulated MMP-1 level by c-Jun regulation. Overall, our findings indicate that RPE evokes skin whitening and anti-wrinkle formation activity by regulating intracellular signaling, supporting its utility as an ingredient for skin whitening and anti-wrinkle cosmetic products.

Therapeutic Effects of Cold-Pressed Perilla Oil Mainly Consisting of Linolenic acid, Oleic Acid and Linoleic Acid on UV-Induced Photoaging in NHDF Cells and SKH-1 Hairless Mice

Positive physiological benefits of several plant oils on the UV-induced photoaging have been reported in some cell lines and model mice, but perilla oil collected from the seeds of Perilla frutescens L. has not been investigated in this context. To study the therapeutic effects of cold-pressed perilla oil (CPO) on UV-induced photoaging in vitro and in vivo, UV-induced cellular damage and cutaneous photoaging were assessed in normal human dermal fibroblasts (NHDFs) and HR-1 hairless mice. CPO contained five major fatty acids including linolenic acid (64.11%), oleic acid (16.34%), linoleic acid (11.87%), palmitic acid (5.06%), and stearic acid (2.48%). UV-induced reductions in NHDF cell viability, ROS production, SOD activity, and G2/M cell cycle arrest were remarkably improved in UV + CPO treated NHDF cells as compared with UV + Vehicle treated controls. Also, UV-induced increases in MMP-1 protein and galactosidase levels were remarkably suppressed by CPO. In UV-radiated hairless mice, topical application of CPO inhibited an increase in wrinkle formation, transepidermal water loss (TEWL), erythema value, hydration and melanin index on dorsal skin of UVB-irradiated hairless mice. CPO was observed to similarly suppress UV-induced increases in epidermal thickness, mast cell numbers, and galactosidase and MMP-3 mRNA levels. These results suggest CPO has therapeutic potential in terms of protecting against skin photoaging by regulating skin morphology, histopathology and oxidative status.

Incorporating Cellular Stochasticity in Solid-Fluid Mixture Biofilm Models

The dynamics of cellular aggregates is driven by the interplay of mechanochemical processes and cellular activity. Although deterministic models may capture mechanical features, local chemical fluctuations trigger random cell responses, which determine the overall evolution. Incorporating stochastic cellular behavior in macroscopic models of biological media is a challenging task. Herein, we propose hybrid models for bacterial biofilm growth, which couple a two phase solid/fluid mixture description of mechanical and chemical fields with a dynamic energy budget-based cellular automata treatment of bacterial activity. Thin film and plate approximations for the relevant interfaces allow us to obtain numerical solutions exhibiting behaviors observed in experiments, such as accelerated spread due to water intake from the environment, wrinkle formation, undulated contour development, and the appearance of inhomogeneous distributions of differentiated bacteria performing varied tasks.

Hydrangenol Isolated from the Leaves of Hydrangea serrata Attenuates Wrinkle Formation and Repairs Skin Moisture in UVB-Irradiated Hairless Mice

Our previous study showed that hydrangenol isolated from Hydrangea serrata leaves exerts antiphotoaging activity in vitro. In this study, we determined its antiphotoaging effect in UVB-irradiated HR-1 hairless mice. We evaluated wrinkle formation, skin thickness, histological characteristics, and mRNA and protein expression using qRT-PCR and Western blot analysis in dorsal skins. Hydrangenol mitigated wrinkle formation, dorsal thickness, dehydration, and collagen degradation. Hydrangenol increased the expression of involucrin, filaggrin, and aquaporin-3 (AQP3) as well as hyaluronic acid (HA) production via hyaluronidase (HYAL)-1/-2 downregulation. Consistent with the recovery of collagen composition, the expression of Pro-COL1A1 was increased by hydrangenol. Matrix metalloproteinase (MMP)-1/-3, cyclooxygenase-2 (COX-2), and interleukin-6 (IL-6) expression was reduced by hydrangenol. Hydrangenol attenuated the phosphorylation of mitogen-activated protein kinases (MAPKs) including ERK and p38, activator protein 1 (AP-1) subunit, and signal transduction and activation of transcription 1 (STAT1). Hydrangenol upregulated the expression of nuclear factor-E2-related factor 2 (Nrf2), heme oxygenase-1 (HO-1), NAD(P)H quinone dehydrogenase 1 (NQO-1), glutamate cysteine ligase modifier subunit (GCLM), and glutamate cysteine ligase catalysis subunit (GCLC). Taken together, our data suggest that hydrangenol can prevent wrinkle formation by reducing MMP and inflammatory cytokine levels and increasing the expression of moisturizing factors and antioxidant genes.

Protective effects of astaxanthin on skin deterioration

Astaxanthin is a carotenoid with potent antioxidant and anti-inflammatory activity. To evaluate the anti-inflammatory effect of astaxanthin on skin deterioration, we confirmed its role in epidermal-dermal interactions in vitro. Astaxanthin treatment suppressed ultraviolet B (UVB)-induced inflammatory cytokine secretion in keratinocytes, and matrix metalloproteinase-1 secretion by fibroblasts cultured in UVB-irradiated keratinocyte medium. To verify these findings, we conducted a 16-week clinical study with 65 healthy female participants. Participants were orally administered either a 6 mg or 12 mg dose of astaxanthin or a placebo. Wrinkle parameters and skin moisture content significantly worsened in the placebo group after 16 weeks. However, significant changes did not occur in the astaxanthin groups. Interleukin-1α levels in the stratum corneum significantly increased in the placebo and low-dose groups but not in the high-dose group between weeks 0 and 16. This study was performed in Japan from August to December, when changing environmental factors, such as UV and dryness, exacerbate skin deterioration. In conclusion, our study suggests that long-term prophylactic astaxanthin supplementation may inhibit age-related skin deterioration and maintain skin conditions associated with environmentally induced damage via its anti-inflammatory effect. (UMIN Clinical Trials Registry ID: UMIN000018550)

Effects of Collagen Tripeptide Supplement on Photoaging and Epidermal Skin Barrier in UVB-exposed Hairless Mice

Collagen tripeptide (CTP) is a functional food material with several biological effects such as improving dry skin and wound and bone fracture healing. This study focused on the anti-photoaging effects of CTP on a hairless mouse model. To evaluate the effects of CTP on UVB-induced skin wrinkle formation in vivo, the hairless mice were exposed to UVB radiation with oral administration of CTP for 14 weeks. Compared with the untreated UVB control group, mice treated with CTP showed significantly reduced wrinkle formation, skin thickening, and transepidermal water loss (TEWL). Skin hydration and hydroxyproline were increased in the CTP-treated group. Moreover, oral administration of CTP prevented UVB-induced MMP-3 and -13 activities as well as MMP-2 and -9 expressions. Oral administration of CTP increased skin elasticity and decreased abnormal elastic fiber formation. Erythema was also decreased in the CTP-treated group. Taken together, these results strongly suggest that CTP has potential as an anti-photoaging agent.

Model based design of inhibitors for c-jun

Literature shows that various molecular cascades are activated by stress, UV rays and pollutants leading to wrinkle formation of the skin. These cascades start from five types of receptors (EGFR, PDGFR, PAFR, IL1R, TNFRB) and terminate with the production of matrix metalloproteinase's, which degrades collagen leading to wrinkle formation. Signaling pathway leading to wrinkle formation showed that c-jun is involved in these cascades. Therefore, c-jun is the preferential choice for inhibition to reduce the intensity of collagen degradation. Hence, the 3D structure of c-jun was modeled using segment based homology modeling by MODELLER 9v5. Evaluation of the constructed model was done by PROCHECK, WHAT CHECK and through RMSD/RMSF calculations. Ligands for the inhibitory sites were designed using LIGANDSCOUT. The interaction study of ligand and receptor was performed by AUTODOCK. A library of analogues was constructed for three known inhibitory sites. The receptor-analogue study was performed using the software MOLEGRO Virtual Docker. The analogues constructed from the designed novel reference ligands showed good binding with the receptor binding sites. It should be noted that these predicted data should be validated using suitable assays for further consideration.