Skin Potential Research Articles

A highly elastic, Room-temperature repairable and recyclable conductive hydrogel for stretchable electronics

Conductive hydrogels present great potential in bioelectronics, ionotronic devices, and electronic skin. However, the creeping and plastic deformation of hydrogel often lead to poor stability and low reliability in applications. Here, we report a highly elastic conductive hydrogel based on crosslinked carbon nanotubes (CNT) and poly(vinyl alcohol) (PVA). With the formation of double crosslinking interactions, i.e., strong interaction from covalent acetal bonds and weak interaction from hydrogen bonds, CNT-PVA networks exhibit good stretchability (fracture stain up to 500%), rapid recovery, zero-residual deformation, and excellent mechanical stability. As such, the electromechanical response of this dual-crosslinked conductive hydrogel is stable and repeatable for a wide range of loading rates. Benefiting from the abundant hydroxyl groups and reversible acetal linking bridges in hydrogel networks, the prepared conductive hydrogel is not only repairable at room temperature, but also recyclable.

Extreme Temperature-Tolerant Conductive Gel with Antibacterial Activity for Flexible Dual-Response Sensors.

Flexible sensors based on conductive hydrogel show great potential in electronic skin and human-machine interface. However, pure water in hydrogel inevitably freezes or rapidly evaporates under extreme temperatures, leading to inadequate fulfillment of sensor performances. Herein, a well-designed strategy is reported for fabricating extreme temperature-tolerant gel-based sensors. By immersing a gelatin/polyacrylamide (PAAm)-clay composite (GC) hydrogel into a ZnCl2/water/glycerol system, a phase-transition-tunable gel (PTTGC gel) is obtained with outstanding antifreezing (-82 °C) and long-lasting moisture (70 °C, more than 40 days) properties. Meanwhile, the gel also presents good antibacterial activity and biocompatibility attributing to Zn2+ and gelatin, respectively. Then, a dual-response sensor with a wide operating temperature (-60 to 60 °C) is proposed, presenting high stress and temperature sensitivities and long-term stability. The sensor will meet the needs of the human-machine interface for scientific investigation and data monitoring in polar, desert, etc.

Enhanced protective potential of novel citronella essential oil microsponge hydrogel against Anopheles stephensi mosquito

Abstract Citronella oil has been frequently used as an insect repellant and antibacterial agent for management of vector borne diseases. In this study, the fabrication of citronella oil microsponge loaded hydrogel (HG-COMS) was conceptualized in order to provide future insight for developing delayed release formulation. The hydrogel was characterized for drug content, drug interaction studies, spreadability, texture analysis and in vitro occlusive behaviour and results were found satisfactory. Further, in vitro antimicrobial studies were carried out to compare the antimicrobial inhibitory potential of the HG-COMS against citronella oil loaded hydrogel (HG-CO). HG-COMS formulation showed better antimicrobial efficacy than HG-CO (zone of inhibition of E. coli, P. aeruginosa and S. aureus; with P value less than 0.01, 0.001 and 0.05, respectively). In addition, the safety (irritation potential) of the oil loaded hydrogel formulation was assessed by Hen’s Egg Test Chorioallantoic Membrane (HAT-CAM) method. Mosquito repellent activity against Anopheles stephensi (malaria vector mosquito) was also performed in a net cage having blood starved female mosquitoes. The repellent potential of prepared HG-COMS (34% repellency for 6 h) was found dependent on release of CO from the microsponges as well as from the gel matrix. HET-CAM test revealed that HG-COMS (irritation score: 6.43 ± 0.77) was found very promising in comparison to HG-CO (irritation score: 12.77 ± 0.36), and was thus, considered safer for dermal use. HG-COMS showed reduced frequency of application, no skin irritation and potential for controlling A. stephensi for longer time periods. Hence, HG-COMS is found as a promising eco-friendly protective option, to minimize the burden of mosquito-transmitted diseases, especially malaria in future.

Location, selection, and comparative anatomy of "Taixi" (KI3), "Shuiquan" (KI5), "Fuliu" (KI7), "Jiaoxin" (KI8), "Zhubin" (KI9), and "Yingu"(KI10) acupoints in rabbits

To investigate the. for locating and selecting the acupoints of "Taixi" (KI3), "Shuiquan" (KI5), "Fuliu" (KI7), "Jiaoxin" (KI8), "Zhubin" (KI9), and "Yingu" (KI10) and the morphological structure of these acupoints in rabbits. MethodsAccording to the WHO and national standards for human acupoints and rabbit X-ray images, acupoint locations were marked using the anatomical landmarks on body surface in 10 New Zealand rabbits. The acupoints were dissected to compare the homologous and analogous tissue between rabbits and human body and thus correct the locations of these acupoints. Potentials were measured for the 10 New Zealand rabbits at the corrected locations of the acupoints and around the acupoints, and the final locations of these acupoints were determined by comparing the anatomical results and the data of potentials. Anatomical observation was performed after marking, and the relationship between acupuncture needle and adjacent structure was observed. "Taixi" was located in the ankle area, at the midpoint between the prominence of the medial malleolus and the calca-neal tendon; "Shuiquan" was located in the calcaneal area below "Taixi" in the depression anterior to the calcaneal tuberosity; "Fuliu" was located at the medial side of the calf, at 2 cun above the prominence of the medial malleolus anterior to the calcaneal tendon; "Jiaoxin" was located at the medial side of the calf, at 2 cun above the prominence of the medial malleolus and in the depression posterior to the medial border of the tibia; "Zhubin" was located at the medial side of the calf, at 5 cun above the medial malleolus on the line between "Taixi" and "Yingu"; "Yingu" was located at the medial side of the knee, at the posterior-inferior border of the semitendinosus tendon on the popliteal crease. The results of skin potentials at the acupoints suggested that "Taixi", "Shuiquan", "Fuliu", and "Zhubin" were high-reliability acupoints, "Jiaoxin" was a medium-reliability acupoint, and "Yingu" was a low-reliability acupoint. Comparative anatomy combined with imaging, surface anatomy, and electrophysiological techniques of acupoints can help with the accurate localization and selection of acupoints in experimental animals, improve the reliability of acupoint location, and enrich the comparative anatomical data of acupoints.

Flaxseed (Linum usitatissimum) Extract Activity on Human Oral Fibroblasts (HOrF) Cell Line

General health benefits have been demonstrated by natural products. Flaxseed (Linum usitatissimum) extract’s bioactivities have been reported in many studies such as antimicrobial, anti-oxidant, and anti-inflammatory effects. In addition, flaxseed extract has skin wound healing activity and potential for treating oral ulcers. Methodology: L. usitatissimum was extracted using 70% ethanol via soxhlet method, gas chromatography mass spectrum (GC-MS) was used to illustrate the components of L. usitatissimum extract. Human oral fibroblasts (HOrF) were cultured to be used for testing the activity of L. usitatissimum. 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide (MTT) assay was used to assess the HOrF cells viability at different time point; 24, 48 and 72 hours. Wound healing assay was used to monitor the healing of HOrF cells after treating them with flaxseed extract. The results of the assay were obtained at 18, 24, 48 and 72 hours. Results: The results of GC-MS illustrate the major components present in L. usitatissimum extract. The effect of L. usitatissimum extract on HOrF cells show high proliferation effect at 24 and 48 hours while the highest proliferation effect was recorded at 72 hours’ post-treatment. Wound healing assay results show healing activity of L. usitatissimum extract on HOrF cells as fast as 18 hours’ post-treatment. Conclusion: L. usitatissimum extract have proliferating and healing effects on HOrF cell line. Therefore, it can be considered as a potential promising oral wound healing agent.

Tuning electroluminescence performance in Pr-doped piezoelectric bulk ceramics and composites

Alternating current electroluminescence (ACEL) shows great potential in lighting, display and intelligent skin. Herein, the ACEL properties of Pr3+-doped Ba0·85Ca0·15Ti0·90Zr0·10O3 ceramic and its PDMS-based composite have been investigated. Intense red EL emission was obtained in the ceramic sample whereas blue EL emission of Pr3+ was observed for the first time in the composite counterpart. The red EL emission should be attributed to the impact of hot electrons driven by the large piezoelectric electric field. Owing to the cross-relaxations through the 4f5d levels and Pr-to-metal charge transfer state, the 3PJ emissions were completely quenched, and thus leading to an enhancement in red emission. However, external E field induced a large local piezoelectric deformation of the ceramic particles embedded in the PDMS matrix, which in turn caused a bending of CB and then a downwards shift of the 4f5d levels from the CB. Hence the cross-relaxations were hindered, and the blue EL emission was observed in the composites. The results would attract attention of functional materials studies and expand our understanding of such facile structure and oxide EL devices to facilitate their use in integral part of flexible device systems.

Large-Area, Flexible SnS/Paper-Based Piezoresistive Pressure Sensor for Artificial Electronic Skin Application

This report demonstrates the fabrication of SnS/paper based low-cost and flexible pressure sensor, employing a facile solvothermal synthesis followed by vacuum filtration, for artificial electronic skin and touchpad applications. The fabricated pressure sensor displayed a high sensitivity of 3.18 kPa <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">-1</sup> and a response time ~300 msec. Inspired by the high value of sensitivity and an appreciable flexibility, a large-area pressure sensor array (3 × 3) was fabricated and integrated onto a human arm for demonstrating real-time applications. The fabricated sensor array was able to consistently detect and track random localized points of contact, the shape of an unknown object placed on top of it, and an index finger trajectory along the surface with high accuracy and precision. The fabricated device showed a negligible change in the performance over 500 bending cycles which indicates the highly robust nature of the device. Successful fabrication of such a cost-effective large-area pressure sensor array is a major step in flexible electronics, and holds immense potential in artificial electronic skin, security, personal healthcare applications.

Lef1 expression in fibroblasts maintains developmental potential in adult skin to regenerate wounds.

Scars are a serious health concern for burn victims and individuals with skin conditions associated with wound healing. Here, we identify regenerative factors in neonatal murine skin that transforms adult skin to regenerate instead of only repairing wounds with a scar, without perturbing development and homeostasis. Using scRNA-seq to probe unsorted cells from regenerating, scarring, homeostatic, and developing skin, we identified neonatal papillary fibroblasts that form a transient regenerative cell type that promotes healthy skin regeneration in young skin. These fibroblasts are defined by the expression of a canonical Wnt transcription factor Lef1 and using gain- and loss of function genetic mouse models, we demonstrate that Lef1 expression in fibroblasts primes the adult skin macroenvironment to enhance skin repair, including regeneration of hair follicles with arrector pili muscles in healed wounds. Finally, we share our genomic data in an interactive, searchable companion website (https://skinregeneration.org/). Together, these data and resources provide a platform to leverage the regenerative abilities of neonatal skin to develop clinically tractable solutions that promote the regeneration of adult tissue.

Abstract 4898: The contribution of human papilloma virus infection to cutaneous squamous cell carcinoma in patients with chronic lymphocytic leukemia

Abstract Background: Human papilloma virus (HPV) is the most common sexually transmitted disease worldwide. α-genus HPV have oncogenic potential in anogenital skin and mucosa. Transplant patients have an increased incidence of β-genus HPV-associated cutaneous squamous cell carcinoma (cSCC). The host immune system is particularly important in the pathogenicity of HPV infection. The antibody-mediated, humoral immune response clears virus particles from body fluids and prevents re-infection. Cell-mediated immunity clears the virus from infected cells, generating immune memory. Impaired cell-mediated immunity is considered a primary risk factor in HPV-induced cSCC in the immunosuppressed population. Patients with chronic lymphocytic leukemia (CLL), a B-cell malignancy characterized by impaired humoral immunity, are at increased risk of developing cSCC. The purpose of this study is to explore the potential role of HPV in malignancies with impaired humoral response. Methods Primary cSCC tissue DNA was isolated from patients diagnosed with CLL. The tissue was analyzed for the presence of HPV. Diagnostic specimens underwent consensus dermatopathology review. Peripheral blood analytes and clinical parameters for disease course were statistically analyzed in conjunction with histopathology. Results Eleven patients with CLL contributed 37 cSCCs. In 49% of the lesions, HPV was detected. Among the cSCC lesions, 27% of the lesions contained β-genus HPV and 30% contained α-genus HPV. The most frequently reported virus was HPV-27 (α-genus), with 16% of lesions containing this variant which is frequently associated with cutaneous warts rather than cSCC. A majority of the HPV-containing lesions displayed moderate dermal lymphocytic inflammation. The lesions were often documented in sun exposed areas such as the scalp and face. Interestingly, HPV-16 and HPV-18, often found in anogenital epithelia, were detected in sun exposed skin in 14% of the lesions examined. In those patients who had documented immunoglobulins, all had hypogammaglobulinemia. Conclusions We examined clinical, histopathologic, and viral genotypes of the cSCCs in patients with CLL. It is widely accepted that CLL patients have a higher incidence and recurrence of cSCC; however, the characteristics of the lesions and the potential association to HPV has not been reported. In our cohort, the lesions were as likely to contain HPV from the α- or β- genus. HPV-27, normally associated with warts, displayed an atypical pathology. The presence of HPV-16 and -18 in sun exposed areas, suggests a novel pathology in compromised humoral immunity. Although our analysis derived some interesting associations, the role for HPV in cSCC in patients with impaired humoral immunity requires further characterization. This is particularly important as we explore the role of vaccinations in reducing HPV-associated malignancies. Citation Format: Preeya Bhavsar, Mugahed Hamza, Sepideh Mehravaran, Qin He, Steven Tyring, Peter Rady, Bhuvaneswari Krishnan, Gustavo Rivero, Daniel N. Cohen, Iberia Romina Sosa. The contribution of human papilloma virus infection to cutaneous squamous cell carcinoma in patients with chronic lymphocytic leukemia [abstract]. In: Proceedings of the Annual Meeting of the American Association for Cancer Research 2020; 2020 Apr 27-28 and Jun 22-24. Philadelphia (PA): AACR; Cancer Res 2020;80(16 Suppl):Abstract nr 4898.

240 In vitro and in vivo skin efficacy of CBD extract

Cannabidiol (CBD) has been implicated as beneficial in variety of skin conditions, including acne, atopic dermatitis, psoriasis, scleroderma, and pruritis. CBD mediates its effect through skin’s own endocannabinoid system composed of CB1 and CB2 receptors, but detailed mechanism of action in skin and clinical efficacy potential needs to be established. In this study we investigated the role of CBD on modulation of heat shock protein pathway in human dermal fibroblasts. Cells were treated with various concentration of CBD and amount of HSP-70 induced was evaluated by ELISA. In addition, clinical efficacy was assessed using an in vivo model. Erythema was induced by topical methyl nicotinate (MN), leading to prostaglandin release and vasodilatation of the peripheral blood capillaries of the skin. CBD was shown to significantly stimulate HSP70 protein level in human dermal fibroblast cells as well as reduce erythema in a clinical model of redness.

Simultaneous measurement of electrodermal activity components correlated with age-related differences.

Electrodermal activity (EDA) measurements are influenced by various factors. Age-related psychological and physiological changes may be considered as one of the possible factors which may influence EDA measurements. In order to properly investigate the effects of such factors on EDA, techniques of precisely and simultaneously recording more than one EDA parameter are recommended. This study aims to explore the impact of age-related differences on EDA components through employing a new measuring technique, which is composed of a small front-end electronic box, DAQ card, and a laptop running LabVIEW software. It is dependent on the simultaneous recording of three EDA parameters: skin conductance (SC), skin potential (SP), and skin susceptance (SS) at the same skin site. EDA components as results of breathing, mathematical tasks, and image stimuli were recorded from 60 healthy participants simultaneously at the same skin site. They were categorized by age into young adults (ages 18-25), middle-aged adults (ages 30-40), and old adults (ages 50-70) years. It was found that skin potential responses (SPRs), and skin conductance level (SCL) (p < 0.001), were significantly decreased due to aging, but changes in other EDA parameters were nonsignificant (p > 0.05). Moreover, both tonic and phasic SS were the least affected and found to be more robust than SC and SP with respect to aging. The study suggests that it is important to take age into account in research studies where the mean aim of the study is to compare EDA parameters; however, in the meantime, the results from our small number and specific study population cannot be generalized to clinical applications.

Coupling acid pretreatment and dosing of Ni and Se enhances the biomethane potential of hazelnut skin

This study offers new insights and promising perspectives in view of the energy valorization of hazelnut skin (HS) as a potential feedstock for renewable biomethane production. The process originally comprised the coupling of chemical pretreatments and individual dosing of cobalt (Co), nickel (Ni) and selenium (Se) as enhancement strategies of the biochemical methane potential (BMP) of HS. The anaerobic digestion (AD) of the untreated HS resulted in a biomethane production of 299 ± 3 mL CH4·g VS−1. This was not positively nor negatively influenced by the addition of the three trace elements (TEs). Performing a 1% H2SO4 pretreatment on HS, a 104% increase of the biomethane yield (i.e. 612 ± 20 mL CH4·g VS−1) was obtained. Under the same pretreatment conditions, a peak of 66.2 mg HAc g VS−1 of total volatile fatty acids (VFAs) was achieved. The BMP of the H2SO4-pretreated HS was further improved by 12 and 16% through the addition of 90 μg Ni·g TS−1 and 270 μg Se·g TS−1 of HS, respectively. The application of a 1.6% NaOH pretreatment on HS led to a 41% higher BMP (i.e. 423 ± 24 mL CH4·g VS−1) compared to that achieved with the untreated material. However, not statistically significant effects were observed when dosing the TEs. In conclusion, a positive synergy between chemical pretreatments and TE supplementation was only observed with the H2SO4- pretreated HS. This was due to the higher VFA production and the more effective VFA conversion to methane in the presence of Ni and Se.

Safety and efficacy of Capsozyme SB Plus (α-galactosidase and endo-1,4-β-xylanase) as a feed additive for poultry species for fattening or reared for laying and ornamental birds.

Following a request from the European Commission, the EFSA Panel on Additives and Products or Substances used in Animal Feed (FEEDAP) was asked to deliver a scientific opinion on the safety and efficacy of Capsozyme SB Plus as a zootechnical feed additive (digestibility enhancers) for poultry species and ornamental birds. The additive contains two enzyme activities (α‐galactosidase and endo‐1,4‐β‐xylanase) and it is presented in solid form. The α‐galactosidase is produced by a non‐genetically modified strain of Aspergillus tubingensis and the xylanase is produced by a non‐genetically modified strain of Trichoderma longibrachiatum. Based on the results obtained in a tolerance trial performed in chickens for fattening, the FEEDAP Panel concluded that the additive is safe for the target species at the recommended levels. The mixture of the two enzyme concentrates that are used to formulate the additive, did not show any potential for a genotoxic effect in a bacterial reverse mutation assay and an in vitro mammalian cell micronucleus test. However, owing to the limitations identified in the subchronic oral toxicity study, the Panel could not conclude on the toxicological potential of the additive. No studies were submitted by the applicant to address the safety aspects related to the user. Therefore, the Panel could not conclude on the skin or eye irritation potential of the additive nor on its skin sensitisation potential. Owing to the proteinaceous nature of the additive it should be regarded as a potential respiratory sensitiser, but the exposure is presumed to be limited due to the low dusting potential. The Panel considered that the product, used as feed additive, poses no risks to the environment and no further environmental risk assessment is required. The Panel considered a total of five efficacy trials, however, the limited evidence of the efficacy provided by those studies did not allow the Panel to conclude on the efficacy.

Gender Differences in Tonic and Phasic Electrodermal Activity Components

Electrodermal activity (EDA) is a well-established psychophysiological measurement for research and clinical approaches. Males and females often display different physiological responses to stimuli, which can be detected by EDA recordings. Using a new method to measure skin conductance (SC), skin potential (SP) and skin susceptance (SS) simultaneously at the same electrode, these differences were investigated. SC, SP, and SS were recorded from 60 participants during relaxation and stress. It was found that both tonic and phasic EDA parameters indicated gender differences. In addition, females displayed greater tonic and phasic EDA parameters (except for skin potential responses (SPRs)) than males under both relaxation and conditions of stimulation (stress). However, these results were not statistically significant (p &gt; 0.05). This suggests that it is perhaps important to consider gender or at least note type of gender in EDA researches, but this cannot be generalized to clinical approaches.

The effect of immobilized antioxidant enzymes on the oxidative stress in UV-irradiated rat skin.

Aim: Superoxide dismutase (SOD) and catalase (CAT) immobilized on gold nanoparticles (AuNP) and silver nanoparticles (AgNP) nanoparticles were used to reduce UV radiation-induced oxidative stress in rat skin. Materials & methods: The antioxidant influence of the enzymes was investigated on level of malondialdehyde, 8-hydroksy-2'deoksyguanozine, myeloperoxidase, total antioxidant capacity, SOD2 and CAT activity and expression, and glutathione and glutathione peroxidase activity. Results: The application of immobilized SOD and CAT on UV-irradiated skin reduced malondialdehyde and 8-hydroksy-2'deoksyguanozine levels also SOD and CAT activity and expression increased. The tested enzymes influence glutathione peroxidase activity and level of total antioxidant capacity and glutathione. Conclusion: Immobilized enzymes increased the antioxidative potential of skin following UV irradiation.

NEUROIMMUNOENDOCRINE REGULATION OF THE SKIN FUNCTIONING

The review deals with modern ideas of neuroimmunoendocrine regulation of physiological and pathophysiological processes in skin. The present data are provided which indicate to composite mechanisms of intercellular interactions in complex regulating systems (nervous, immune, endocrine) acting at the level of skin in normal conditions, as well during the posttraumatic period. We describe different modes for participation of endocrine and nervous systems in immunologically induced skin inflammation. The data are provided confirming localization of adrenergic receptors on membranes of immunocompetent cells and leukocytes, on regulatory effects of hypothalamus upon immune functions, about multidirectional actions upon inflammation of sympathetic and parasympathetic nervous system etc.There are sufficient data on promotion of pathophysiological changes and reconstitution processes in the skin due to effects of local immune cells and bioactive substances expressed by them. The course of skin wound regeneration depend on the type of damage, degree and a phase of healing process. Posttraumatic reparative potential of skin is often limited by the infectious processes initiated by local microflora, products of cell disintegration and necrotic tissues. The cause-effect relationship is proven by arising inflammation which is implemented by inclusion of immune protection responses. The increased necrotic area and suppuration of the wound occurs die to inhibition of system of the phagocytizing macrophages. However, activation of this system brings about formation of the connective tissue capsule around the inflammation focus within early terms.We also discuss the issues of reparative skin regeneration which of great medico-social value, in connection with considerable prevalence of traumatic events and their social consequences, followed by expressed cosmetic defects. Evolving neurocognitive problems lead to decreased quality of the patient’s life, development of social disadaptation and further deprivation. The role of nervous system and psychological frustration in genesis of skin manifestations requires future development of the modern scientific direction, i.e., psychodermatology.Understanding of molecular mechanisms regulating the neuroimmunocutaneous interactions offers new prospectives in treatment of some skin diseases, as well as activation of the damaged skin recovery. According to the data presented in the review article, one may conclude on relevance of further studies on reparative potential of skin under interactions of homeostatic regulatory systems.

SOURSOP POTENCY AS THE SUBSTRATE IN NATA DE ANONNA PRODUCTION

Nata is a functional food that has a healthy effect when consumed because it contains vitamin C which is beneficial to the body. Nata derived from soursop fruit, we know as nata de anonna, which is produced from the bacterial activity of Acetobacter xylinum. This study aims to determine the potential of soursop fruit skin as a substrate for making nata de anonna. Research shows that the yield nata produced from soursop fruit and soursop skin and soursop meat are (1.5 cm, 1 cm and 0.8 cm). This research can be concluded that the hump and soursop skin which become waste are part of the soursop fruit can be used as the substrate of nata de anonna.

Potensi Antimikroba Ekstrak Etanol Kulit Luar Buah Cempedak (Artocarpus integer (Thunb.) Merr.)

The background of this research is to develop the potential of biological resources in South Kalimantan. In particular, the biological source is cempedak fruit. The use of cempedak which has been scientifically studied is the use of cempedak bark as anti-malaria. Other studies related to other parts of cempedak are still not widely used. Based on the potential possessed by cempedak bark, it is likely that other parts of cempedak also have potential as traditional medicine. This study aims to identify the content of secondary metabolites from the outer skin of cempedak fruit, analyze the potential of the outer skin of cempedak fruit as an antimicrobial and analyze the effective dose as an antimicrobial. The method used to see MIC values with liquid dilution and KBM values with solid dilution. The results of phytochemical identification showed that the ethanol extract of the outer skin of cempedak fruit contained secondary metabolites in the form of saponins, tannins, flavonoids and alkaloids which have antimicrobial potential. The results of the antimicrobial activity test showed the MIC value of the ethanol extract of cempedak fruit outer skin against Escherichia coli bacteria at a concentration of 50% and against Staphylococcus aureus at a concentration of 25%. The KBM value also shows the same value as KHM. Based on the results of the study it can be concluded that the ethanol extract of cempedak fruit outer skin has broad-spectrum antimicrobial activity.

Multifunctional and high-performance electronic skin based on silver nanowires bridging graphene

Graphene has great potential in the electronic skin to monitor physiological signals. However, many cracks are generated in graphene during the deformation of human body, which would form the open circuit and decrease the measure range, sensitivity, and stability of devices. To solve the problem, we find the answer in higher plant, whose symplasm consists of cytoplasm and plasmodesmata. Cytoplasm is wrapped in hard cell wall like the open circuit of graphene crack. The intercellular communication can only be achieved through plasmodesmata, a nanochannel connecting adjacent cytoplasm. In this article, by imitating the plasmodesmata, a silver nanowires (AgNWs) bridging laser scribed graphene oxide electronic skin (GES) have been proposed with a customized pattern. Compared with the pure GES, the plasmodesmata-like AgNWs bridging GES shows much better performance of mechanical sensitivity and measuring range. Mechanical signals such as pulse, respiration, and joint movement can be detected. In addition, the impedance between GES and skin decreases drastically. More importantly, the excellent matching of the AgNWs bridging GES electrode with the current commercial module facilitates the real-time monitoring of electrocardiogram (ECG) and electroencephalogram (EEG) signals. This work has great potential in the real-time, wearable, and multifunctional physiological monitoring system.

The regenerative potential of skin and the immune system.

Skin has the natural ability to heal and replace dead cells regulated by a network of complex immune processes. This ability is conferred by the population of resident immune cells that act in coordination with other players to provide a homeostatic environment under constant challenge. Other than providing structure and integrity, the epidermis and dermis also house distinct immune properties. The dermal part is represented by fibroblasts and endothelial cells followed by an array of immune cells which includes dendritic cells (DCs), macrophages, mast cells, NK-cells, neutrophils, basophils, eosinophils, αβ T lymphocytes, B-cells and platelets. On the other hand, the functionally active immune cells in the epidermis comprise keratinocytes, DCs, NKT-cells, γδ T cells and αβ T cells (CD4+ and CD8+). Keratinocytes create a unique microenvironment for the cells of the immune system by promoting immune recognition and cellular differentiation. T lymphocytes exhibit tissue-specific tropism toward the epidermis and the lymphatic drainage system important for their function in immune regulation. This diversity in immune regulators makes the skin a unique organ to overcome pathogenic or foreign invasion. In addition, the highly coordinated molecular events make the skin an attractive model to understand and explore its regenerative potential.