Skin Water Content Research Articles

Influence of Bases for External Medicines with Different Coatability and Water Retentivity on Wound Healing

When selecting external medicines for the treatment of skin diseases, it is thought to be very important to consider differences in characteristics of their bases, because the bases may influence the clinical efficacy of the medicines. In this study, we investigated whether the differences in characteristics of three kinds of bases, white petrolatum, macrogol ointment, and aqueous gel affect wound healing. In vitro moisture permeability tests demonstrated that these bases have different characteristics in coatability and water retentivity, with the rank order of the intensity of coatability as white petrolatum>macrogol ointment>aqueous gel, and that of water retentivity as macrogol ointment>white petrolatum>aqueous gel. Similar rank order of these bases was observed for transepidermal water loss and stratum corneum water content in the dry skin on the abdomen of guinea pigs induced by topical application of acetone/ether mixture, followed by water. In addition, we found that treatment with macrogol ointment, but not white petrolatum or aqueous gel, significantly accelerated wound healing in rat skin, and that the contents of basic fibroblast growth factor and epidermal growth factor in the skin treated with macrogol ointment were significantly higher compared with non-treated skin. In conclusion, these results imply an important role of the bases of external medicines in the treatment of skin diseases.

Segmentation Method of Skin MRI 3D High Resolution in vivo

Background: In recent years, Magnetic Resonance Imaging (MRI) is used in clinical application as non-invasive medical modality, it is rarely used to study the anatomy physiological, and biochemical of the skin, in spite of its very attractive modality for skin imaging. It makes an ideal imaging modality of unique soft tissue contrast to study the skin water content and to differentiate between the different skin layers. However MRI provides a big data with high quality. The analysis of these data require computerized methods to help clinicians and to improve disease of diagnosis. Several image processing method have been extensively used to assist doctors in qualitative diagnosis, segmentation is one of the most methods used in medical image processing for many applications in order to understand medical data and extract useful information.
 The purpose of this study is to use the segmentation method to measure the hydration of skin using MRI modality.
 Methods: We will classify segmentation approaches for MRI data into three basics classes: Edge based segmentation, Region based segmentation, and Thresholding segmentation. Then we will briefly describe Fuzzy C-means Clustering method. Furthermore, we will give some related works used FCM algorithm with MRI images.
 Results: We have measured the hydration of the feet as a result of the FCM segmentation method, where the sample of the study was conducted on 35 healthy volunteers, who were scanned by MRI machine before applying moisturizer and one hour after.
 Conclusion: MRI is an attractive modality to study the skin water content, it makes an ideal observation of the different skin layers in vivo with three dimensions. However, the segmentation of MRI data by FCM clustering is a computerized method to help clinicians in order to measure skin hydration.

Capacitive Imaging for Skin Characterizations and Solvent Penetration Measurements

Capacitive contact imaging has shown potential in measuring skin properties including hydration, micro relief analysis, as well as solvent penetration measurements. Through calibration, we can also measure the absolute permittivity of the skin, and from absolute permittivity we then work out the absolute water content and absolute solvent content in skin. This paper presents our latest study of capacitive contact imaging for skin characterizations and vivo skin solvent penetration. The results show that with capacitive contact imaging, it is possible not only to assess the skin damaging, but also potentially possible to differentiate different types of skin damages. The results also show that with capacitive contact imaging, it is also possible to measure the solvent penetration through skin and to quantify the solvent concentration within skin.

Using therapeutic ultrasound to promote irritated skin recovery after surfactant-induced barrier disruption

BackgroundSurfactant-induced skin barrier disruption can enhance blood flow and water content in the superficial skin. The effect of therapeutic ultrasound on accelerating the recovery of superficial skin after skin barrier disruption has seldom been studied. ObjectiveTo understand the effects of therapeutic ultrasound on barrier recovery, we used the sodium lauryl sulfate irritation model and treatment with ultrasound intervention. MethodsThe study allocated 30 healthy subjects into an ultrasound group (n = 15) and a control group (n = 15), each divided into three subgroups (sodium lauryl sulfate at concentrations of 1.0%, 0.5%, and 0%). Pulsed ultrasound (1 MHz, 0.3 W/cm2SATA) was applied to ultrasound subgroups. The treatment effect was evaluated by the recovery rate of enhanced blood flow and water content. ResultsThe results indicated a surfactant dose-dependent effect on blood flow, but not on water content. The recovery rates of enhanced blood flow were higher in the 0.5% and 1.0% ultrasound subgroups than in the control subgroups throughout the experiment. However, recovery rates of water content were higher in the ultrasound subgroups than in the control subgroups only on Day2. ConclusionsPulsed ultrasound accelerated the barrier recovery by reducing the enhanced blood flow and water content after skin barrier disruption.

Study on the development of wax emulsion with liquid crystal structure and its moisturizing and frictional interactions with skin

The moisturizing and frictional interactions between emulsion and skin have a significant influence on the moisturizing efficacy and sensory properties of cosmetics. To deeply understand the interactions, we developed a kind of wax emulsion with liquid crystal structure and studied their interactions with dry, semi-moist and fully-moist skin. The moisturizing interaction was studied by using skin hydration test and tape stripping analysis, and it was found that with the increasing of liquid crystal content in the emulsion, the skin hydration level increased, desquamation index decreased and number of cutaneous lines increased, suggesting the increased moisturizing effect and barrier function. The frictional interaction was studied by finger friction test, and it was found that firstly during and after the application of emulsion on skin, the frictional interaction followed the stribeck-curve rule of lubrication. Secondly, when changing the water content of the substrate skin, the frictional behavior of the whole system showed a bell-curve behavior. Both skin hydration and water amount in the interfacial film played role in the frictional interaction between emulsion and skin, and the frictional interaction mechanism between wax emulsion and finger skin with different type of skin was proposed. This was the first time to study and discuss the effect of skin moist status on the moisturizing and frictional interactions between cosmetic emulsion and skin. The findings were significant for the design of high quality personal care products.

Experimental Drainage Device to Reduce Lymphoedema in a Rat Model

Despite recent advances in pharmacological research and microsurgery, lymphoedema remains an incurable disease that deeply affects quality of life. There is an urgent need for innovative approaches to restore continuous lymph flow in affected tissues. To this end, the efficacy of a subcutaneously implanted draining device in reducing lymphoedema volume in a rat hindlimb lymphoedema model was tested. A rat model of chronic lymphoedema was developed by surgical removal of popliteal and inguinal lymph nodes, followed by irradiation. The model was characterised by monitoring limb volume via tape measure, skin water content via dielectric constant measurement, and lymphatic drainage via lymphofluoroscopy. After lymphoedema establishment in 16 Wistar rats, a device made of fenestrated tubing equipped with a miniaturised pumping system, was implanted subcutaneously in the affected limb to restore continuous recirculation of interstitial fluid. Lymphofluoroscopy imaging showed impaired lymphatic drainage following lymphadenectomy and irradiation. Affected limb volume and skin water content increased significantly compared with the untreated limb, with a median (interquartile range) of 3.85 (0.38) cm3 versus 3.03 (0.43) cm3 for volume (n=16, p=.001) and 26.6 (9.1) versus 16.6 (3.7) cm3 for skin dielectric constant (n=16, p=.001). Treatment of lymphoedema with the implanted drainage device showed that 5 weeks post-implant excess volume was significantly reduced by 51±18% compared with the pre-implant situation (n=9 sham group, n=7 pump group). Lymphoedema volume in the rat model was significantly reduced by restoring continuous drainage of excess fluid using a novel subcutaneously implanted device, opening the way to the development of an artificial lymphatic vessel.

Efficacy of heparinoid moisturizer as a prophylactic agent for radiation dermatitis following radiotherapy after breast-conserving surgery: a randomized controlled trial.

The application of heparinoid moisturizer for 2 weeks following whole-breast radiotherapy (WBRT) was previously reported to significantly increase skin water content (WC) and help improve skin dryness and desquamation. The prospective open-label, randomized trial included an exploratory arm to investigate the preventive efficacy of heparinoid moisturizer for acute radiation dermatitis (ARD). Between April 2011 and April 2013, patients receiving WBRT were assigned (1:2:2) to receive either: moisturizer for prophylaxis (group P), moisturizer starting 2 weeks after WBRT for treatment (group M), and no moisturizer (group C). This paper presents the results of comparison between the exploratory arm and no moisturizer group. Skin WC was measured prior to WBRT, on the last day of WBRT, and 2 weeks, 4 weeks and 3 months following WBRT. Signs and symptoms were also assessed. Comparing two groups, WC values were significantly higher in group P until 4 weeks following WBRT. At 2 weeks following WBRT, mean WC values in group P and C were 38.5 ± 6.1 arbitrary units (a.u.) and 30.2 ± 7.8 a.u., respectively (P < 0.001). In group C, dryness was more severe at 2 and 4 weeks following WBRT and desquamation more severe until 3 months following WBRT. However, the erythema score showed no difference between the two groups. Regarding symptoms, group C pain scores on the last day of WBRT were significantly higher than in group P (P < 0.030). The preventive application of heparinoid moisturizer has the potential of reducing skin desquamation and dryness in patients receiving WBRT.

Structural properties and protective effect of Sargassum fusiforme polysaccharides against ultraviolet B radiation in hairless Kun Ming mice

Sargassum fusiforme polysaccharide (SFP) was extracted from Sargassum fusiforme by hot water boiling, concentration and ethanol precipitation. The composition was determined as 58.10 ± 2.12% carbohydrate, 1.01 ± 0.15% protein, 9.85 ± 0.96% sulfate group and 17.66 ± 0.54% glucuronic acid. The average molecular weight of SFP was 224 kDa. The monosaccharide composition of SFP was 43.2% L-fucose, 3.5% rhamnose, 18.4% galactose, 1.5% glucose, 18.5% fructose, 5.9% xylose and 9.0% mannose respectively. SFP showed significant protective effect against ultraviolet B (UVB) radiation in hairless Kun Ming (KM) mice by manipulating the skin water content and thymus and spleen indexes. SFP could also alleviate UVB-induced oxidative stress by enhancing the activities of superoxide dismutase (SOD) and catalase (CAT) and reducing the levels of reactive oxygen species (ROS) and malondialdehyde (MDA) equivalents. The levels of matrix metalloproteinase (MMP)-1 and 9 were also suppressed in SFP treatments. These findings suggest that SFP could be used as a potential functional food supplement for skin protection.

Rice bran supplement prevents UVB-induced skin photoaging in vivo.

Although rice bran consumption is reportedly has numerous beneficial effects on human health, the relationship between rice bran and the prevention of photoaging has not been investigated in detail. We sought to investigate whether consumption of rice bran supplement (RBS) can elicit preventive effects against UVB-induced photoaging in vivo. Dorsal skin sections of hairless mice were exposed to UVB over 16weeks. RBS consumption suppressed UVB-induced wrinkle formation and inhibited the loss of water content and epidermal thickening in the mouse skin. Western blot and immunohistochemical analyses revealed that repeated exposure to UVB upregulated matrix metalloproteinase-13 (MMP-13) and cyclooxygenase-2 (COX-2) expression, while consumption of RBS suppressed MMP-13 and COX-2 expression, as well as mitogen-activated protein kinase (MAPK) signaling pathways. These findings suggest that RBS could be a potential bioactive ingredient in nutricosmetics to inhibit wrinkle formation and water content loss via the suppression of COX-2 and MMP-13 expression.

SGLT-2-inhibition with dapagliflozin reduces tissue sodium content: a randomised controlled trial

Background and aimsSodium tissue content by 23Na magnetic resonance imaging (Na-MRI) has been validated in experimental and human studies. SGLT-2 inhibition blocks the reabsorption of glucose and of sodium in the proximal tubular cells in a 1:1 fashion. We hypothesized that SGLT-2 inhibition in patients with type 2 diabetes characterized by sodium retention leads to decreased tissue sodium content due to its pharmacological action.Materials and methodsIn a prospective double blind, placebo controlled, cross-over trial 59 patients (61 ± 7.6 years) with type 2 diabetes were randomized to either dapagliflozin 10 mg or placebo once daily for 6 weeks each. In addition to metabolic parameters and ambulatory blood pressure (BP) we analysed the sodium content in the skin and muscles of the lower leg by Na-MRI.ResultsCompared to baseline 6 weeks treatment with the SGLT-2 inhibitor dapagliflozin decreased fasting (132 ± 28 vs. 114 ± 19 mg/dl, p < 0.001), postprandial blood glucose (178 ± 66 mg/dl vs. 153 ± 46 mg/dl, p < 0.001), body weight (87.6 vs. 86.6 kg, p < 0.001) and systolic (129 ± 12 vs. 126 ± 11 mmHg, p = 0.010), and diastolic (77.4 ± 9 vs. 75.6 ± 8 mmHg, p = 0.024), 24-h ambulatory BP. Tissue sodium content in the skin was reduced after 6 weeks treatment with dapagliflozin compared to baseline [24.1 ± 6.6 vs. 22.7 ± 6.4 A.U.(arbitrary unit) p = 0.013]. No significant reduction of tissue sodium content was observed in the muscle (M. triceps surae: 20.5 ± 3.5 vs. 20.4 ± 3.7 A.U. p = 0.801). No clear significant difference in tissue water content of muscle and skin was observed after 6 weeks of treatment with dapagliflozin, compared to baseline.ConclusionSGLT-2 inhibition with dapagliflozin resulted in a significant decrease in tissue sodium content of the skin after 6 weeks. This observation point to a decrease of total sodium content in patients with type 2 diabetes prone to cardiovascular complications, that might be mitigated by SGLT-2 inhibition.Trial registration The study was registered at http://www.clinicaltrials.gov (NCT02383238) retrospectively registered

Age and Hydration dependence of jowl and forearm skin firmness in young and mature women.

Quantitative assessment of possible linkages between skin's firmness and water content is useful for cosmetic and clinical purposes and to better understand features of advancing age. Our goals were to characterize age-related differential features in skin firmness in women and determine the relationship between skin firmness and indices of skin water. Skin firmness was quantified using handheld devices that measure the force to indent skin 0.3 and 1.3 mm (F0.3 and F1.3). Skin hydration was quantified using handheld devices that measured tissue dielectric constant (TDC) at 300 MHz to skin depths of 0.5 and 2.0-2.5 mm. All parameters were measured bilaterally in the jowl area and volar forearm of 60 women grouped by age <45 years (YOUNG) and ≥45 years old (MATURE). All measured parameters were bilaterally symmetrical at jowl and forearm. Forearm and jowl indentation forces were greater in YOUNG with statistically significant declines with advancing age with regression relations most evident at shallower indentation depths (P < .001). Quantitative relations for arm and jowl were F0.3 = 0.256 × AGE + 32.7 mN and F0.3 = -0.07 × AGE + 17.7 mN. Firmness was related to TDC values only when indentation force and TDC were assessed on the arm at the shallowest skin depths, as weakly related to firmness and was observed to change with age only when measured to a depth of 0.5 mm represented by TDC5 = 0.096 × AGE + 32.7. Experimental finding show clear differences in skin firmness between age-groups with skin hydration playing a minor role. Possible explanations and suggestions for further studies are provided.

Differences of skin characteristics between face and hand and its correlation with age in female from Shanghai

Objective To estimate the differences between face and hand skin and age correlation in females aged 23-46 years living in Shanghai. Methods 139 women aged 23-46 years from Shanghai attended this program. The water content, pH, TEWL and elasticity of cheek, forehead, hand back of and palm were evaluated by non-invasive skin test instruments. Results The skin water content of these four parts from high to low were forehead, cheek, hand back and palm, and they were different from each other significantly. The pH of cheek was the highest, and forehead was the lowest; there was no significant difference between hand back and palm. TEWL of palm was the highest, and cheek was the lowest; the difference between forehead and hand back was inconsistent in different age groups. The elasticity of cheek was the highest. There was no significant difference in R2between forehead, hand back and cheek. The condition of R5 and R7 was different between younger group and older group. In young group the cheek was the highest, and palm was the lowest. In older group, cheek and forehead, palm and hand back began to converge. In addition to the elasticity of cheek and hand back, other parameters of other parts had no significantly difference between different age groups, and also had no significant correlation. Conclusions The cheek has the best skin barrier, elasticity and the highest pH, and the elasticity of cheek decreases with age. The forehead has the highest water content and lowest pH, TEWL and the elasticity of hand back are close to the forehead, and the elasticity of hand back decreases with age. The palm has the highest TEWL and lowest water content. Its total recovery amount in the elastic curve is higher, but the elastic ratio in the recovery is the lowest. Key words: Face; Hand; Skin characteristics; Age

Tissue dielectric constant and circumference measurement in the follow-up of treatment-related changes in lower-limb lymphedema.

Lymphedema of lower limbs is a chronic condition that requires life-long management. Therapeutic effect of complex decongestive physiotherapy (CDP) is most often followed by circumference measurements (CM). However, the CM measurements are not specific to interstitial tissue fluid and have problems in sensitivity and objectivity. The aim of present study was to evaluate the therapeutic effect of CDP with a new tissue water specific measurement technique, in patients with lower limb lymphedema (LLL). A total of 17 patients with unilateral LLL (11 primary, 6 secondary lymphedema) were recruited in this study. CDP was applied for 5 days a week for 4 weeks. CM measurement of both limbs was performed at nine sites along limb by tape measure. Percentage skin water content (PWC) of thigh, calf and ankle was measured in affected lymphedema limb and contralateral limb with MoistureMeterD Compact (MMDC) device. Inter-limb PWC ratio was calculated by dividing affected side's PWC value with PWC of contralateral limb. Patients were asked to fullfill the Lymph Quality of Life Questionnaire. Significant reduction of circumference after CDP was detected at all nine measurement sites along lower limb (P<0.01). PWC measurements showed a significant decrease of skin tissue water at thigh, calf and ankle measurement sites after CDP (P<0.001). Inter-limb PWC ratios demonstrated significant reduction of edema between affected and contraletral limbs post-treatment (P<0.003). CDP also increased the quality of life (P=0.006). CM and PWC measurements reflected a positive effect of CDP in patients with LLL. Both absolute PWC values and inter-limb PWC ratios were meaningful tools to follow the effect of therapautic intervention. Compared with CM measurements the TDC technique offered easier, quicker, objective and more practical measurements for routine assessments of LLL.

Skin targeting of curcumin solid lipid nanoparticles-engrossed topical gel for the treatment of pigmentation and irritant contact dermatitis

Irritant contact dermatitis (ICD) and hyperpigmentation are the problems associated with skin. Topical curcumin (CUR) although effective in hyperpigmentation and ICD, is a challenging molecule due to low-solubility. Encapsulation of CUR into solid lipid nanoparticles (SLNs) makes it amenable to topical dosing as their small size promotes its penetration into the skin. CUR-SLNs were prepared using Precirol ATO5 and Tween-80 by probe ultrasonication method. Further, CUR-SLNs were incorporated into Carbopol gel and investigated for ex-vivo skin permeation, skin deposition and skin irritation studies. The potential of CUR-SLN gel was checked against hyperpigmentation through the inhibition of tyrosinase enzyme. It was further evaluated for possible effects on ICD using BALB/c mice. The optimized CUR-SLN showed the particle size of 51 nm and 93% EE. Ex vivo permeation of CUR-SLN gel exhibited controlled drug release up to 24 h, similarly in vitro drug deposition studies showed potential for skin targeting. In vitro tyrosinase inhibition assay indicates that the formulated gel has potential in skin depigmentation. The gel also confirmed proficient suppression of ear swelling and reduction in skin water content in the BALB/c mouse. Thus, the CUR-SLN gel would be a safe and effective alternative to conventional vehicles for treatment of ICD and pigmentation.

Formulation and development of Silybin loaded solid lipid nanoparticle enriched gel for irritant contact dermatitis

The purpose of the present research was to develop Silybin loaded solid lipid nanoparticle gel (SIL-SLN gel) for irritant contact dermatitis (ICD). ICD is associated with reduced skin water content, emerging in dry skin condition and relapsing eczema. SIL is a naturally occurring flavones, which shows antioxidant activity and helps in the treatment of ICD. In this study, the SLN was prepared by the ultrasonic probe sonication method and further evaluated for particle size and entrapment efficiency. Results of optimized batch showed mean particle size 139 ± 0.35 nm and entrapment efficiency 90.97 ± 0.91%. Optimized batch was freeze dried and characterized by field emission scanning electron microscopy (FE-SEM), it shows particles are in nano range, with spherical morphology and smooth surface. Finally, the SLN was incorporated into gel for convenient topical application. The SIL-SLN-gel were evaluated for in-vitro skin occlusivity, skin irritation and ex-vivo diffusion and deposition study and further compared with SIL-plain gel. Efficacy of gel on dinitrochlorobenzene (DNCB) induced ICD mice were evaluated by skin water content, ear swelling and histopathology. Ex-vivo study of SIL-SLN gel exhibited prolonged drug release, whereas the skin irritation study shows no irritancy. In DNCB induced ICD mice SIL-SLN gel showed higher efficacy than SIL-plain gel.

Beneficial effects of dried pomegranate juice concentrated powder on ultraviolet B-induced skin photoaging in hairless mice

The present study investigated the anti-aging effects of pomegranate juice concentrated powder (PCP) in hairless mice following 15 weeks of UVB irradiation (three times a week; 0.18 J/cm2). Skin moisturizing effects were evaluated through skin water, collagen type I and hyaluronan contents, as well as collagen type I and hyaluronan synthesis-related transcript levels. Wrinkle formation and edema scores (skin weights) were also assessed, along with skin matrix metalloproteinase (MMP)-1, MMP-9 and MMP-13 transcript levels. To determine the anti-inflammatory effects of PCP, myeloperoxidase (MPO) activity, interleukin (IL)-1β and IL-10 contents were observed. Caspase-3 and cleaved poly(ADP-ribose) polymerase (PARP) were used as an apoptotic index in epidermal keratinocytes. To determine the anti-oxidative effects of PCP, nitrotyrosine and 4-hydroxynonenal immunoreactive cells were detected and glutathione (GSH) content, malondialdehyde levels, superoxide anion production, Nox2, and GSH reductase mRNA expression were all measured. The results indicated that skin wrinkles induced by photoaging were significantly reduced by PCP, whereas skin water contents, collagen type I and hyaluronan contents all increased. Furthermore, IL-1β levels in the PCP-treated groups were lower than those in the UVB-exposed control group. UVB-induced GSH depletion was also inhibited by PCP. Taken together, the results of the current study suggest that PCP has favorable protective effects against UVB-induced photoaging through anti-apoptotic effects, MMP activity inhibition and ECM (COL1 and hyaluronan) synthesis-related moisturizing, anti-inflammatory and anti-oxidative effects.

Skin hydration analysis by experiment and computer simulations and its implications for diapered skin.

Experimental work on skin hydration is technologically challenging, and mostly limited to observations where environmental conditions are constant. In some cases, like diapered baby skin, such work is practically unfeasible, yet it is important to understand potential effects of diapering on skin condition. To overcome this challenge, in part, we developed a computer simulation model of reversible transient skin hydration effects. Skin hydration model by Li etal. (Chem Eng Sci, 138, 2015, 164) was further developed to simulate transient exposure conditions where relative humidity (RH), wind velocity, air, and skin temperature can be any function of time. Computer simulations of evaporative water loss (EWL) decay after different occlusion times were compared with experimental data to calibrate the model. Next, we used the model to investigate EWL and SC thickness in different diapering scenarios. Key results from the experimental work were: (1) For occlusions by RH=100% and free water longer than 30minutes the absorbed amount of water is almost the same; (2) Longer occlusion times result in higher water absorption by the SC. The EWL decay and skin water content predictions were in agreement with experimental data. Simulations also revealed that skin under occlusion hydrates mainly because the outflux is blocked, not because it absorbs water from the environment. Further, simulations demonstrated that hydration level is sensitive to time, RH and/or free water on skin. In simulated diapering scenarios, skin maintained hydration content very close to the baseline conditions without a diaper for the entire duration of a 24hours period. Different diapers/diaper technologies are known to have different profiles in terms of their ability to provide wetness protection, which can result in consumer-noticeable differences in wetness. Simulation results based on published literature using data from a number of different diapers suggest that diapered skin hydrates within ranges considered reversible.

Influence of water content on Raman spectroscopy characterization of skin sample.

We report that the Raman spectrum obtained from porcine skin varies significantly with the change of skin water content. At different water contents from 40 to 55 wt.%, the Raman spectra results using confocal Raman spectroscopy show that the spectral variation of porcine skin is highly affected by skin water content. Experimental data are consistent with the Monte Carlo calculation and it is proved that the intensity of the Raman spectrum depends on the angle distribution and collection efficiency of backscattered light from the sample surface for a varied water content. It is suggested that water content for a given skin sample should be controlled carefully to minimize errors and deviations in the Raman peak analyses.

Porous Ionic Membrane Based Flexible Humidity Sensor and its Multifunctional Applications.

A highly flexible porous ionic membrane (PIM) is fabricated from a polyvinyl alcohol/KOH polymer gel electrolyte, showing well‐defined 3D porous structure. The conductance of the PIM changes more than 70 times as the relative humidity (RH) increases from 10.89% to 81.75% with fast and reversible response at room temperature. In addition, the PIM‐based sensor is insensitive to temperature (0–95 °C) and pressure (0–6.8 kPa) change, which indicates that it can be used as highly selective flexible humidity sensor. A noncontact switch system containing PIM‐based sensor is assembled, and results show that the switch responds favorably to RH change caused by an approaching finger. Moreover, an attachable smart label using PIM‐based sensor is explored to measure the water contents of human skin, which shows a great linear relationship between the sensitivity of the sensor and the facial water contents measured by a commercial reference device.

Extract of Polygala tenuifolia Alleviates Stress-Exacerbated Atopy-Like Skin Dermatitis through the Modulation of Protein Kinase A and p38 Mitogen-Activated Protein Kinase Signaling Pathway

Atopic dermatitis (AD) and stress create a vicious cycle: stress exacerbates atopic symptoms, and atopic disease elicits stress and anxiety. Targeting multiple pathways including stress and allergic inflammation is, therefore, important for treating AD. In this study, we investigated the remedial value of Polygala tenuifolia Willd. (PTW) for treating immobilization (IMO) stress-exacerbated atopy-like skin dermatitis and its underlying mechanism. Trimellitic anhydride (TMA) was applied to dorsal skin for sensitization and subsequently both ears for eliciting T-cell-dependent contact hypersensitivity in mice, which underwent 2 h-IMO stress and PTW administration for the latter 6 and 9 days in the ear exposure period of TMA, respectively. To elicit in vitro degranulation of human mast cell line-1 (HMC-1), 10 µM substance P (SP) and 200 nM corticotrophin-releasing factor (CRF) were sequentially added with 48 h-interval. PTW extract (500 µg/mL) was added 30 min before CRF treatment. IMO stress exacerbated TMA-induced scratching behavior by 252%, and increased their blood corticosterone levels by two-fold. Treatment with 250 mg/kg PTW significantly restored IMO stress-exacerbated scratching behavior and other indicators such as skin inflammation and water content, lymph node weights, and serum histamine and immunoglobulin E (lgE) levels. Furthermore, it also reversed TMA-stimulated expression of tumor necrosis factor (TNF)-α and interleukin (IL)-4 mRNAs in ear tissues. PTW significantly inhibited SP/CRF-stimulated degranulation of HMC-1 cells, subsequent tryptase secretion, and protein kinase A (PKA) activity. PTW also selectively inhibited p38 mitogen-activated protein kinase (MAPK) phosphorylation in SP/CRF-treated HMC-1 cells. PTW significantly inhibited HMC-1 cell degranulation and alleviated IMO stress-exacerbated atopic dermatitis symptoms by modulating the PKA/p38 MAPK signaling pathway.