The demand for wearable, stretchable soft electronics for human–machine interface applications continues to grow given the potential of these devices in humanoid robotics, prosthetics, and ...health-monitoring devices. We demonstrate fabrication of multifunctional sensors with simultaneous temperature-, pressure-, proximity-, and strain (or bending)-sensing capabilities, combined with heating and UV-protection features. These multifunctional sensors are flexible, light, and transparent and are thus body-attachable. Silver nanowires are supersonically sprayed on a large-scale transparent and flexible roll-to-roll substrate. The junctions between nanowires are physically fused by a strong impact resulting from supersonic spraying, which promotes adhesion and efficient deposition of the nanowire network. Accordingly, nanowires are strongly interconnected, facilitating efficient propagation of electric signals through the fused nanowire network, which allows simultaneous operation of such sensors while maintaining significant transparency. These multifunctional sensors are mechanically durable and retain long-term stability. A theoretical discussion is provided to explain the respective mechanisms of heating and proximity, pressure, and strain sensing.
A versatile biomimetic theranostic agent based on magnetic melanin nanoparticles is developed for positron‐emission tomography/magnetic resonance/photoacoustic/photothermal multimodal‐imaging‐guided ...cancer photothermal therapy and UV and γ‐irradiation protection.
The Roles of Vitamin C in Skin Health Pullar, Juliet M; Carr, Anitra C; Vissers, Margreet C M
Nutrients,
08/2017, Letnik:
9, Številka:
8
Journal Article
Recenzirano
Odprti dostop
The primary function of the skin is to act as a barrier against insults from the environment, and its unique structure reflects this. The skin is composed of two layers: the epidermal outer layer is ...highly cellular and provides the barrier function, and the inner dermal layer ensures strength and elasticity and gives nutritional support to the epidermis. Normal skin contains high concentrations of vitamin C, which supports important and well-known functions, stimulating collagen synthesis and assisting in antioxidant protection against UV-induced photodamage. This knowledge is often used as a rationale for the addition of vitamin C to topical applications, but the efficacy of such treatment, as opposed to optimising dietary vitamin C intake, is poorly understood. This review discusses the potential roles for vitamin C in skin health and summarises the in vitro and in vivo research to date. We compare the efficacy of nutritional intake of vitamin C versus topical application, identify the areas where lack of evidence limits our understanding of the potential benefits of vitamin C on skin health, and suggest which skin properties are most likely to benefit from improved nutritional vitamin C intake.
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•Green synthesis of ZnO nanoparticles using A. indica leaf by different calcination.•Prepared ZnONps characterised and compared to the lower calcination.•The structural morphology and ...antimicrobial activity of ZnONps were investigated.•To enhanced the Hydrophobicity and UV-protection for biomedical applications.
In this study, ZnO nanoparticles were green-synthesized from Acalypha indica leaf extract using zinc acetate as a precursor. The prepared ZnO nanoparticles were calcined at three different temperatures, namely 100, 300, and 600 °C. The structure/morphology of the green-synthesized ZnO nanoparticles was ascertained through X-ray diffraction, particle size analysis, scanning electron microscopy, transmission electron microscopy, and surface area analysis techniques. It was observed from the physico-chemical and biological characterization studies that ZnO nanoparticles calcined at high temperature (600 °C) exhibit high surface area (230 m2 g−1) and small particle size (20 nm) with good antibacterial activity against Escherichia coli (22.89 ± 0.06 mm) and Staphylococcus aureus (24.62 ± 0.08 mm). In addition, cotton fabrics coated with these nanoparticles showed higher UV-protection (87.8 UPF), hydrophobicity (155°), and maximum zone of bacterial inhibition against E. coli and S. aureus (25.13 ± 0.05 mm and 30.17 ± 0.03 mm) than those coated with particles calcined at 100 °C and 300 °C. High temperature calcination has a vital role in the crystallization of the particles towards nanoscale with increased resistivity to UV exposure, washing treatments, and microbial infection in fabrics. Thus, the cost-effective ZnO nanoparticles obtained through green synthesis method proves their potential applications in the field of biomedical, textile, and cosmetic applications.
Cellulosic fabrics made of cotton, linen, bamboo, hemp, and nettle, were selected for the eco-sustainable production of colored biofunctional textiles, using natural dyes from onion skin of the ...Dorata di Parma (Allium cepa L.) variety. Dyeing experiments were performed in net water with and without pre-treatment with alum, tin chloride, and tannic acid as mordants. The color and the UV-protection factor (UPF) were evaluated through UV–visible spectroscopy. The treatment with onion skin extract induced a relevant increase of UPF in all investigated fabrics, promoting the protection category from insufficient (UPF<15) to good for linen (UPF = 21–26), up to very good and excellent for cotton (UPF = 35–66) and bamboo (UPF = 48–56), respectively. To mimic the direct contact with the skin, textile samples were immersed in artificial sweat where dyed cotton, hemp, and nettle were found to promote higher phenolic release (0.28–0.50 mg gallic acid equivalents/g textile) than linen and bamboo (0.12–0.22 mg gallic acid equivalents/g textile). The obtained “biofunctional sweat” did not impact on the survival of primary human dermal fibroblasts (HDF) and skin keratinocytes (NCTC2455), while protected these cells against heat shock and reduced reactive oxygen species levels upon exposure to pro-oxidant and inflammatory agents as H2O2 and lipopolysaccharide, respectively. Increased activity levels of the H2O2-scavenging enzyme Catalase (CAT) were also observed, thus demonstrating enhanced stress response and homeostatic capability of these cells. This study provides evidence that extracts from onion waste can be used to functionalize cellulosic fabrics conferring properties as natural shield against UV radiation, and antioxidant and anti-inflammatory materials thus holding potential in skin protection and prevention of dermatological diseases.
•Onion skin is used for the sustainable coloration of organic cellulosic fabrics.•Dyed cotton, bamboo and linen ensure good to excellent protection from UV radiations.•Dyed nettle, hemp and cotton release higher content of phenols in artificial sweat.•Biofunctional properties of dyed textiles are assessed in vitro on dermal cells.•The phenols released by dyed textiles decreased ROS in H2O2 and heat shock stress skin models.
Renewable and biodegradable plant-derived biomaterials are considered an ideal alternative to non-biodegradable petrochemical plastics. However, the inherent cohesion and mechanical properties of ...biopolymers are usually insufficient to meet the requirements of practical applications. Inspired by the supramolecular chemistry of mussels, we report a facile and sustainable strategy for fabricating a high-performance soy protein (SP)-based film by incorporating polyvinylpyrrolidone (PVP)-functionalized lignosulfonate (LS) hybrids. In this process, the polymerized LS molecules form rigid skeletal domains, and the PVP chains serve as soft components to ensure the flexibility of the composites. An interconnected cross-linking network was constructed in the SP/PVP@LS film via multiple non-covalent interactions including hydrogen bonding, hydrophobic interactions, and π–π interactions. As a result of the synergistic effect of supramolecular interactions, the tensile strength and toughness of the resulting film were significantly enhanced to 16.15 MPa and 23.50 MJ/m3, corresponding to increases of 111.39% and 386.54% relative to the pristine SP film. The SP/PVP@LS film also shows excellent ultraviolet-light resistance, improved flame retardancy, and favorable thermal stability owing to the unique aromatic ring structure and the ketones, phenol units, and chromophore functional groups in the PVP@LS hybrids. The bioinspired design strategy provides an innovative and facile route for producing multifunctional SP-based films for various prospective applications in fields such as biomass adhesives, active packaging, UV-protective coatings, and flame retardants.
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•A supramolecular chemistry strategy is used to prepare a soy protein-based film.•Lignosulfonate (LS) hybrids are functionalized by polyvinylpyrrolidone (PVP).•Multiple cross-linking networks are constructed via noncovalent interactions.•Tensile strength and toughness of the film were increased by 111.39% and 386.54%.•The film shows enhanced UV-blocking, flame retardancy, and thermal stability.
•Natural dye extracted from sawdust of Pterocarpus indicus Willd. using ultrasound.•Dyeing and mordanting parameters were optimized.•Pretreatment of cotton and silk improved colour depth, fastness ...and UV protection.•Timber industry waste can be upcycled as a resource for natural dye.
Exploitation of synthetic dyes in a variety of manufacturing sectors including textiles poses serious problems to the environment. Natural dyes are becoming vital alternatives to toxic synthetic dyes, however, with limitations such as availability and process standardization. Herein, we explore the dyeing potential of a sawdust, Pterocarpus indicus Willd., which is widely available as a waste from timber industry in South Asia and other parts of the world. Ultrasound assisted extraction method was carried out to extract natural dye from the sawdust. The extract was used to dye cotton and silk fabrics using various metallic and natural mordants such as alum, stannous chloride, copper sulphate, gallnut, pomegranate rind and gooseberry and the process was optimized. The effect of different pretreatments such as chitosan and myrobalan on dyeing fabrics was also studied. Colour properties of the naturally dyed fabrics such as colour strength, colour co-ordinates and various fastness were assessed. The natural mordants such as gallnut, pomegranate rind and gooseberry provided comparable fastness property to metallic mordants, thereby suggesting the use of the extracted dye with natural mordants for exclusive eco-friendly dyeing. We also demonstrate that chitosan and myrobalan pretreatments significantly enhance the colour strength, colour fastness and UV protection properties of naturally colored cotton and silk fabrics. Overall, the results suggest copper sulphate mordanting with chitosan pretreatment and stannous chloride mordanting with myrobalan pretreatment as the best combination for cotton and silk fabrics, respectively considering the color fastness and UV protection properties. The results provide ample scope for the upcycling of timber industry waste into a natural dye for eco-friendly coloration of fabrics.
With the increasing population of mosquitoes due to urbanisation, requirement for effective mosquito repellent gadgets is rising. To guarantee the security from mosquitoes, dire need is felt to build ...productive innovations. In the current work, a carbohydrate-based textile fibre was functionalised for imparting colour, mosquito repellency, antibacterial activity and UV protection using a novel polymeric dye. Mosquito repellent 4-amino N,N-diethyl-meta-toluamide (DEET-NH2) was diazotised and reacted with chitosan for the in-situ preparation of azo polymeric dye. The separately prepared polymeric dye was characterised using FTIR (Fourier Transform Infrared Spectroscopy) analysis. In-situ dyed fabric was thoroughly characterised and evaluated for colouration, mechanical and functional properties. The dyed cotton showed an outstanding mosquito repellency (100%) with good durability. Moreover, antibacterial activity (>78%) and UV protection (good to very good) were also displayed by the dyed cotton. An innovative technique to develop multifunctional carbohydrate-based fibre is developed.
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Zinc oxide (ZnO) and titanium dioxide (TiO2) nanoparticles (NPs) are prepared from their salts in form of aqueous suspensions to provide multifunctional cellulosic substrate. ZnO-NPs and TiO2-NPs are ...obtained in the range of 3-5 nm and 8-15 nm, respectively. Prepared suspensions are loaded onto knitted cotton fabrics and fixed using reactive softener and/or citric acid. Antimicrobial activity, ultraviolet protection (UPF) and self-cleaning in respect to metal oxides add-on to the fabrics are investigated. Fabrics treated with ZnO-NPs for 10 g l−1 (white fabrics) and 5 g l−1 (dyed fabrics) were cidal for both gram negative and positive bacteria. Using 5 g l−1 TiO2-NPs in the presence of reactive softener has a bacteriostatic effect and showed a decent bacteria reduction. TiO2-NPs showed the better UPF values than those of ZnO treated fabrics when it compared to the same fabric structure. Discoloration values of TiO2-NPs treated fabrics showed superior color fading over the ZnO-NPs treated samples.
Photostability of sunscreens Kockler, Jutta; Oelgemöller, Michael; Robertson, Sherryl ...
Journal of photochemistry and photobiology. C, Photochemistry reviews,
March 2012, 2012-3-00, Letnik:
13, Številka:
1
Journal Article
Recenzirano
► A comprehensive review of the photostability of physical and chemical UV-filters. ► The major photoreactions of these UV-filters individually and in combination. ► The impact on their ...photostability when used in combination (broad spectrum). ► The effect of the formulation, antioxidants and excipients on photostability. ► The importance of photostability testing for sunscreens, currently not mandatory.
Sunscreens were originally designed to include mainly UVB-filters. Because of the deeper penetration of UVA light, causing photoaging and DNA damage, there has been a shift towards broad spectrum sunscreens. These broad spectrum sunscreens now include both UVA- and UVB-filters and other ingredients which possess antioxidant activity. Although sunscreens are regulated in most countries, photostability testing is not mandatory. Because of the ability of sunscreen ingredients to absorb UV-light and the complexity of most of these formulations, which may include more than one UV-filter, antioxidants and other formulation excipients, it is important that their photostability in combination is determined.
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