Journal articles: 'Silica skins'

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Cai, Yichen, Jie Shen, Chi-Wen Yang, Yi Wan, Hao-Ling Tang, Areej A. Aljarb, Cailing Chen, et al. "Mixed-dimensional MXene-hydrogel heterostructures for electronic skin sensors with ultrabroad working range." Science Advances 6, no. 48 (November 2020): eabb5367. http://dx.doi.org/10.1126/sciadv.abb5367.

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Skin-mountable microelectronics are garnering substantial interest for various promising applications including human-machine interfaces, biointegrated devices, and personalized medicine. However, it remains a critical challenge to develop e-skins to mimic the human somatosensory system in full working range. Here, we present a multifunctional e-skin system with a heterostructured configuration that couples vinyl-hybrid-silica nanoparticle (VSNP)–modified polyacrylamide (PAM) hydrogel with two-dimensional (2D) MXene through nano-bridging layers of polypyrrole nanowires (PpyNWs) at the interfaces, featuring high toughness and low hysteresis, in tandem with controlled crack generation and distribution. The multidimensional configurations endow the e-skin with an extraordinary working range (2800%), ultrafast responsiveness (90 ms) and resilience (240 ms), good linearity (800%), tunable sensing mechanisms, and excellent reproducibility. In parallel, this e-skin platform is capable of detecting, quantifying, and remotely monitoring stretching motions in multiple dimensions, tactile pressure, proximity sensing, and variations in temperature and light, establishing a promising platform for next-generation smart flexible electronics.

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Watchman, Alan. "Perspectives and potentials for absolute dating prehistoric rock paintings." Antiquity 67, no. 254 (March 1993): 58–65. http://dx.doi.org/10.1017/s0003598x00045051.

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Absolute dating of prehistoric rock paintings is an exciting archaeological pursuit. Sophisticated sample collection, handling and pretreatment methods and new analytical equipment and techniques are minimizing contamination and permitting identification of trace amounts of organic substances in prehistoric paints. Radiocarbon dating using Accelerator Mass Spectrometry (AMS) is producing dates for minute residues of blood, charcoal and plant fibres, either accidentally or deliberately incorporated in paintings. Carbon-bearing laminations, such as oxalate-crusts and silica skins, which have accumulated under and over rock art, have also been recently dated.

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Tang, Zhenhua, Shuhai Jia, Xuesong Shi, Bo Li, and Chenghao Zhou. "Coaxial Printing of Silicone Elastomer Composite Fibers for Stretchable and Wearable Piezoresistive Sensors." Polymers 11, no. 4 (April 11, 2019): 666. http://dx.doi.org/10.3390/polym11040666.

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Despite the tremendous efforts dedicated to developing various wearable piezoresistive sensors with sufficient stretchability and high sensitivity, challenges remain pertaining to fabrication scalability, cost, and efficiency. In this study, a facile, scalable, and low-cost coaxial printing strategy is employed to fabricate stretchable and flexible fibers with a core–sheath structure for wearable strain sensors. The highly viscous silica-modified silicone elastomer solution is used to print the insulating sheath layer, and the silicone elastomer solutions containing multi-walled carbon nanotubes (CNTs) are used as the core inks to print the conductive inner layer. With the addition of silica powders as viscosifiers, silica-filled silicone ink (sheath ink) converts to printable ink. The dimensions of the printed coaxial fibers can be flexibly controlled via adjusting the extrusion pressure of the inks. In addition, the electro-mechanical responses of the fiber-shaped strain sensors are investigated. The printed stretchable and wearable fiber-like CNT-based strain sensor exhibits outstanding sensitivities with gauge factors (GFs) of 1.4 to 2.5 × 106, a large stretchability of 150%, and excellent waterproof performance. Furthermore, the sensor can detect a strain of 0.1% and showed stable responses for over 15,000 cycles (high durability). The printed fiber-shaped sensor demonstrated capabilities of detecting and differentiating human joint movements and monitoring balloon inflation. These results obtained demonstrate that the one-step printed fiber-like strain sensors have potential applications in wearable devices, soft robotics, and electronic skins.

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Lee, Sang Gil, Young Ho Kim, Jun Tae Bae, Chung Hee Lee, Hyeong Bae Pyo, Kuk Hyoun Kang, and Dong Kyu Lee. "Fabrication of Hollow Porous Silica Using a Combined Emulsion Sol–Gel Process and Amphiphilic Triblock Copolymer for Loading of Quercetin." Journal of Nanoscience and Nanotechnology 15, no. 10 (October 1, 2015): 7935–41. http://dx.doi.org/10.1166/jnn.2015.11226.

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Flavonoids have recently attracted significant interest as potential reducing agents, hydrogendonating antioxidants, and singlet oxygen-quenchers. Quercetin, in particular, induces the expression of a gene, known to be associated with cell protection, in dose- and time-dependent manners. Therefore, quercetin may be used as an effective cosmeceutical material useful in the protection of dermal skin. In this study, hollow porous silica spheres used to load quercetin were prepared by using a combined emulsion sol–gel process and triblock copolymer as a template. Fabrication of hollow porous silica spheres was performed under various conditions such as the molar ratios of H2O/TEOS (w) and weight ratios of poloxamer 184/poloxamer 407. Loading of quercetin in hollow porous silica spheres was devised to improve the stability of quercetin and to consider the possibility as a raw cosmetic material. The surface of inclusion complexes of quercetin in hollow porous silicas was modified to enhance the stability of quercetin. The physicochemical properties of the samples were investigated using scanning electron microscopy (SEM), Fourier-transform infrared spectroscopy (FT-IR), thermogravimetric analysis (TGA)-differential thermal analysis (DTA) and Brunauer–Emmett–Teller (BET) surface area and porosity analysis. Determination of quercetin concentration was carried out by high-performance liquid chromatography (HPLC) analysis.

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Arriagada, Francisco, and Javier Morales. "Limitations and Opportunities in Topical Drug Delivery: Interaction Between Silica Nanoparticles and Skin Barrier." Current Pharmaceutical Design 25, no. 4 (June 3, 2019): 455–66. http://dx.doi.org/10.2174/1381612825666190404121507.

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The first limiting barrier for the transport in the skin is the stratum corneum; different strategies have been developed to overcome this barrier, including chemical enhancers. However, these penetration enhancers have limitations, including toxic adverse effects. In this context, research into nanomaterials has provided new tools to increase the residence time of drugs by generating a reservoir, increasing the specificity of drugs and reducing their adverse effects, and improving the penetration of drugs that are difficult to formulate. Silica nanoparticles have been proposed as suitable nanocarriers for skin delivery. Unfortunately, the mechanisms involved in the interaction, transport and fate of silica nanoparticles in the skin have not been fully investigated. This paper reviews significant findings about the interaction between silica-based nanocarriers and the skin. First, this review focuses on the properties and functions of the skin, the skin penetration properties of silica nanoparticles, their synthesis strategies and their toxicity. Finally, advances and evidence on the application of silica nanocarriers in skin drug delivery are provided, in which the use of nanoparticles increases the stability and solubility of the bioactive compound, enhancing its performance, act as penetrator enhancer and improving controlled release. Thus, improving the treatment of some skin disorders.

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Kim, Sung-Hyun, Dong Han Lee, SeoYoon Choi, Jun-Young Yang, Kikyung Jung, Jayoung Jeong, Jae Ho Oh, and Jin Hee Lee. "Skin Sensitization Potential and Cellular ROS-Induced Cytotoxicity of Silica Nanoparticles." Nanomaterials 11, no. 8 (August 22, 2021): 2140. http://dx.doi.org/10.3390/nano11082140.

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Nowadays, various industries using nanomaterials are growing rapidly, and in particular, as the commercialization and use of nanomaterials increase in the cosmetic field, the possibility of exposure of nanomaterials to the skin of product producers and consumers is increasing. Due to the unique properties of nanomaterials with a very small size, they can act as hapten and induce immune responses and skin sensitization, so accurate identification of toxicity is required. Therefore, we selected silica nanomaterials used in various fields such as cosmetics and biomaterials and evaluated the skin sensitization potential step-by-step according to in-vitro and in-vivo alternative test methods. KeratinoSensTM cells of modified keratinocyte and THP-1 cells mimicking dendritic-cells were treated with silica nanoparticles, and their potential for skin sensitization and cytotoxicity were evaluated, respectively. We also confirmed the sensitizing ability of silica nanoparticles in the auricle-lymph nodes of BALB/C mice by in-vivo analysis. As a result, silica nanoparticles showed high protein binding and reactive oxygen species (ROS) mediated cytotoxicity, but no significant observation of skin sensitization indicators was observed. Although more studies are needed to elucidate the mechanism of skin sensitization by nanomaterials, the results of this study showed that silica nanoparticles did not induce skin sensitization.

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Becker, Lillian C., Wilma F. Bergfeld, Donald V. Belsito, Ronald A. Hill, Curtis D. Klaassen, Daniel Liebler, James G. Marks, et al. "Safety Assessment of Silylates and Surface-Modified Siloxysilicates." International Journal of Toxicology 32, no. 3_suppl (May 2013): 5S—24S. http://dx.doi.org/10.1177/1091581813486299.

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The Cosmetic Ingredient Review (CIR) Expert Panel assessed the safety of silica silylate, silica dimethyl silylate, trimethylsiloxysilicate, and trifluoropropyldimethyl/trimethylsiloxysilicate as used in cosmetics. These silylates and surface-modified siloxysilicates function in cosmetics as antifoaming agents, anticaking agents, bulking agents, binders, skin-conditioning agents—emollient, skin-conditioning agents—occlusive, slip modifiers, suspension agents—nonsurfactant, and viscosity increasing agents—nonaqueous. The Expert Panel reviewed the available animal and clinical data as well as information from a previous CIR safety assessment of amorphous silica. The CIR Expert Panel concluded that silica silylate, silica dimethyl silylate, trimethylsiloxysilicate, and trifluoropropyldimethyl/trimethylsiloxysilicate are safe as used when formulated and delivered in the final product not to be irritating or sensitizing to the respiratory tract.

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Koul, Ashwani, Stanzin Angmo, and Sanjay Bharati. "Preventive Role of Vitamin D in Silica-Induced Skin Fibrosis: A Study in Relation to Oxidative Stress and Pro-Inflammatory Cytokines." International Journal for Vitamin and Nutrition Research 86, no. 3-4 (June 2016): 88–96. http://dx.doi.org/10.1024/0300-9831/a000434.

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Abstract.The protective effects of vitamin D analogue calcipotriol in silica-induced skin fibrosis were studied in the present study. Male BALB / c mice were divided into four groups; Control, Vitamin D, Silica and Silica+Vitamin D. Silica was administered as a single intradermal injection (40 µg / µL, dissolved in normal saline; particle size 1 – 5 µm) in the hind limbs of animals in Silica & Silica+Vitamin D group. Vitamin D group animals received topical application of 100µL of vitamin D solution (10-7M in Ethanol) daily for 12 weeks. Silica+Vitamin D group animals received co-treatment of silica and vitamin D as described for other groups. After 12 weeks of treatment, dermal thickness and hydroxyproline content of treated sections were measured. The TNF-α and IL-6 levels were measured in serum of all treated animals. The silica-induced oxidative stress was measured in terms of lipid peroxidation in skin tissue. Antioxidant defence system was assessed in terms of levels of reduced glutathione, superoxide dismutase, catalase, glutathione peroxidase and glutathione reductase. A significant increase in the dermal thickness and hydroxyproline content was observed after silica treatment (931 ± 57.98 to 1804.61 ± 146.20 µm)(p < 0.05). Vitamin D co-treatment reduced dermal thickness and hydroxyproline content compared to Silica group (p < 0.05). Similarly a decrease in TNF-α and IL-6 levels were also observed after vitamin D treatment. A significant reduction in oxidative stress in terms of lipid peroxidation (4.92 ± 0.70 to 2.40 ± 0.31 nmol / mg protein). Therefore, present study suggested that vitamin D could be an effective agent against silica-induced skin fibrosis and oxidative stress.

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Vogt, Annika, Fiorenza Rancan, Sebastian Ahlberg, Berouz Nazemi, Chun Sik Choe, Maxim E. Darvin, Sabrina Hadam, et al. "Interaction of dermatologically relevant nanoparticles with skin cells and skin." Beilstein Journal of Nanotechnology 5 (December 8, 2014): 2363–73. http://dx.doi.org/10.3762/bjnano.5.245.

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The investigation of nanoparticle interactions with tissues is complex. High levels of standardization, ideally testing of different material types in the same biological model, and combinations of sensitive imaging and detection methods are required. Here, we present our studies on nanoparticle interactions with skin, skin cells, and biological media. Silica, titanium dioxide and silver particles were chosen as representative examples for different types of skin exposure to nanomaterials, e.g., unintended environmental exposure (silica) versus intended exposure through application of sunscreen (titanium dioxide) or antiseptics (silver). Because each particle type exhibits specific physicochemical properties, we were able to apply different combinations of methods to examine skin penetration and cellular uptake, including optical microscopy, electron microscopy, X-ray microscopy on cells and tissue sections, flow cytometry of isolated skin cells as well as Raman microscopy on whole tissue blocks. In order to assess the biological relevance of such findings, cell viability and free radical production were monitored on cells and in whole tissue samples. The combination of technologies and the joint discussion of results enabled us to look at nanoparticle–skin interactions and the biological relevance of our findings from different angles.

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Arriagada, Francisco, Santi Nonell, and Javier Morales. "Silica-based nanosystems for therapeutic applications in the skin." Nanomedicine 14, no. 16 (August 2019): 2243–67. http://dx.doi.org/10.2217/nnm-2019-0052.

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Aging, exposure to oxidants, infectious pathogens, inflammogens, ultraviolet radiation and other environmental and genetic factors can result in the development of various skin disorders. Despite immense progress being made in dermatological treatments, many skin-associated problems still remain difficult to treat and various therapies have limitations. Progress in silica-based nanomaterials research provides an opportunity to overcome these drawbacks and improve therapies and is a promising tool for inclusion in clinical practice to treat skin diseases. This review focuses on the use of various types of silica nanoparticles with therapeutic applications in various skin disorders. These nanosystems improve treatment efficacy by maintaining or enhancing the effect of several drugs and are useful tools for nanomedicine, pharmaceutical sciences and future clinical applications.

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Park, Ji-Ung, Seol-Ha Jeong, Eun-Ho Song, Juha Song, Hyoun-Ee Kim, and Sukwha Kim. "Acceleration of the healing process of full-thickness wounds using hydrophilic chitosan–silica hybrid sponge in a porcine model." Journal of Biomaterials Applications 32, no. 8 (January 22, 2018): 1011–23. http://dx.doi.org/10.1177/0885328217751246.

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In this study, we evaluated the surface characterization of a novel chitosan–silica hybridized membrane and highlighted the substantial role of silica in the wound environment. The chemical coupling of chitosan and silica resulted in a more condensed network compared with pure chitosan, which was eventually able to stably maintain its framework, particularly in the wet state. In addition, we closely observed the wound-healing process along with the surface interaction between chitosan–silica and the wound site using large-surface-area wounds in a porcine model. Our evidence indicates that chitosan–silica exerts a synergetic effect of both materials to promote a remarkable wound-healing process. In particular, the silica in chitosan–silica accelerated wound closure including wound contraction, and re-epithelialization via enhancement of cell recruitment, epidermal maturity, neovascularization, and granulation tissue formation compared with pure chitosan and other commercial dressing materials. This advanced wound dressing material may lead to effective treatment for problematic cutaneous wounds and can be further applied for human skin regeneration.

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Zhu, Feiyan, Chen Wang, Saina Yang, Qian Wang, Fuxin Liang, Chenyang Liu, Dong Qiu, Xiaozhong Qu, Zhongbo Hu, and Zhenzhong Yang. "Injectable tissue adhesive composite hydrogel with fibroblasts for treating skin defects." Journal of Materials Chemistry B 5, no. 13 (2017): 2416–24. http://dx.doi.org/10.1039/c7tb00384f.

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Physical interactions between glycol chitosan (GC) and silica nano-particles (SiNP) formed a hydrogel, with the features of injectability, skin adhesion and fibroblast encapsulation, which was used as a wound dressing to favor microvessel and hair follicle growth in skin defects.

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Lio, Daniel Chin Shiuan, Chenghao Liu, Myo Myo Swe Oo, Christian Wiraja, Melissa Hui Yen Teo, Mengjia Zheng, Sharon Wan Ting Chew, Xiaomeng Wang, and Chenjie Xu. "Transdermal delivery of small interfering RNAs with topically applied mesoporous silica nanoparticles for facile skin cancer treatment." Nanoscale 11, no. 36 (2019): 17041–51. http://dx.doi.org/10.1039/c9nr06303j.

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Johnson, Candice, Ernst Ahlberg, Lennart T. Anger, Lisa Beilke, Romualdo Benigni, Joel Bercu, Sol Bobst, et al. "Skin sensitization in silico protocol." Regulatory Toxicology and Pharmacology 116 (October 2020): 104688. http://dx.doi.org/10.1016/j.yrtph.2020.104688.

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Alsos, Inger Greve, Sebastien Lavergne, Marie Kristine Føreid Merkel, Marti Boleda, Youri Lammers, Adriana Alberti, Charles Pouchon, et al. "The Treasure Vault Can be Opened: Large-Scale Genome Skimming Works Well Using Herbarium and Silica Gel Dried Material." Plants 9, no. 4 (April 1, 2020): 432. http://dx.doi.org/10.3390/plants9040432.

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Genome skimming has the potential for generating large data sets for DNA barcoding and wider biodiversity genomic studies, particularly via the assembly and annotation of full chloroplast (cpDNA) and nuclear ribosomal DNA (nrDNA) sequences. We compare the success of genome skims of 2051 herbarium specimens from Norway/Polar regions with 4604 freshly collected, silica gel dried specimens mainly from the European Alps and the Carpathians. Overall, we were able to assemble the full chloroplast genome for 67% of the samples and the full nrDNA cluster for 86%. Average insert length, cover and full cpDNA and rDNA assembly were considerably higher for silica gel dried than herbarium-preserved material. However, complete plastid genomes were still assembled for 54% of herbarium samples compared to 70% of silica dried samples. Moreover, there was comparable recovery of coding genes from both tissue sources (121 for silica gel dried and 118 for herbarium material) and only minor differences in assembly success of standard barcodes between silica dried (89% ITS2, 96% matK and rbcL) and herbarium material (87% ITS2, 98% matK and rbcL). The success rate was > 90% for all three markers in 1034 of 1036 genera in 160 families, and only Boraginaceae worked poorly, with 7 genera failing. Our study shows that large-scale genome skims are feasible and work well across most of the land plant families and genera we tested, independently of material type. It is therefore an efficient method for increasing the availability of plant biodiversity genomic data to support a multitude of downstream applications.

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Kuznetsova, Daria, Vadim Elagin, Maria Karabut, Maria Shakhova, Vladimir Bredikhin, Liudmila Snopova, Andrei Shakhov, et al. "The influence on biotissue laser resection of a strongly absorbing layer at the optical fiber tip." Journal of Innovative Optical Health Sciences 09, no. 05 (July 18, 2016): 1650011. http://dx.doi.org/10.1142/s1793545816500115.

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In this paper, we consider a method of laser resection using the silica glass core from which the cladding layer has been removed as the cutting part of a laser scalpel. An absorbing layer coating the silica fiber tip markedly alters its biotissue cutting characteristics. The results of histological studies of skin after exposure to a laser scalpel with and without a strongly absorbing coating (SAC) at a wavelength of 0.97[Formula: see text][Formula: see text]m show that resection using a coated scalpel is more sparing. When an uncoated scalpel was used, skin injury was more apparent in both its surface spread and the depth of structural damage, resulting in poorer tissue regeneration.

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Scodeller, P., P. N. Catalano, N. Salguero, H. Duran, A. Wolosiuk, and G. J. A. A. Soler-Illia. "Hyaluronan degrading silica nanoparticles for skin cancer therapy." Nanoscale 5, no. 20 (2013): 9690. http://dx.doi.org/10.1039/c3nr02787b.

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Nafisi, Shohreh, Naghmeh Samadi, Mahboubeh Houshiar, and Howard I. Maibach. "Mesoporous silica nanoparticles for enhanced lidocaine skin delivery." International Journal of Pharmaceutics 550, no. 1-2 (October 2018): 325–32. http://dx.doi.org/10.1016/j.ijpharm.2018.08.004.

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Jiang, Pei-Cheng, Yu-Ting Chow, Chi-Wei Chien, Cheng-Hsun-Tony Chang, and Chii-Ruey Lin. "Silica Layer Used in Sensor Fabrication from a Low-Temperature Silane-Free Procedure." Chemosensors 9, no. 2 (February 4, 2021): 32. http://dx.doi.org/10.3390/chemosensors9020032.

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Silica (SiO2, silicon dioxide—a dielectric layer commonly used in electronic devices) is widely used in many types of sensors, such as gas, molecular, and biogenic polyamines. To form silica films, core shell or an encapsulated layer, silane has been used as a precursor in recent decades. However, there are many hazards caused by using silane, such as its being extremely flammable, the explosive air, and skin and eye pain. To avoid these hazards, it is necessary to spend many resources on industrial safety design. Thus, the silica synthesized without silane gas which can be determined as a silane-free procedure presents a clean and safe solution to manufactures. In this report, we used the radio frequency (rf = 13.56 MHz) plasma-enhanced chemical vapor deposition technique (PECVD) to form a silica layer at room temperature. The silica layer is formed in hydrogen-based plasma at room temperature and silane gas is not used in this process. The substrate temperature dominates the silica formation, but the distance between the substrate and electrode (DSTE) and the methane additive can enhance the formation of a silica layer on the Si wafer. This silane-free procedure, at room temperature, is not only safer and friendlier to the environment but is also useful in the fabrication of many types of sensors.

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MACKAY, C., S. BAJARIA, G. SHAVER, K. KUDRYCKI, S. RAMANUJAN, T. PATERSON, C. FRIEDRICH, G. MAXWELL, I. JOWSEY, and D. LOCKLEY. "In silico modelling of skin sensitisation." Toxicology 231, no. 2-3 (March 7, 2007): 103. http://dx.doi.org/10.1016/j.tox.2006.11.027.

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Patel, Shreeya, Kathleen Morrisroe, Susanna Proudman, Dylan Hansen, Joanne Sahhar, Malcolm R. Sim, Gene-Siew Ngian, et al. "Occupational silica exposure in an Australian systemic sclerosis cohort." Rheumatology 59, no. 12 (September 10, 2020): 3900–3905. http://dx.doi.org/10.1093/rheumatology/keaa446.

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Abstract Objective To determine the frequency of self-reported occupational exposure to silica in SSc patients enrolled in the Australian Scleroderma Cohort Study, and to compare the disease characteristics of the silica-exposed patients with those of the non-exposed patients. Method Data collected over a 12-year period from 1670 SSc patients were analysed. We compared the demographic and clinical characteristics of those who reported occupational silica exposure with those who did not. A subgroup analysis of male patients was performed, as well as a multivariable analysis of correlates of silica exposure. Results Overall, 126 (7.5%) of the cohort reported occupational silica exposure. These individuals were more likely to be male (73 of 231, i.e. 31.6% males exposed) and to have worked in mining and construction industries. Those who reported silica exposure were younger at the onset of SSc skin involvement [odds ratio (OR) 0.9, P = 0.02], of male gender (OR 14.9, P < 0.001), have joint contractures (OR 1.8, P = 0.05) and have higher physical disability as defined by scleroderma HAQ (OR 1.4, P = 0.01). Conclusion The highest percentage of silica exposure was found in males. These patients were more likely to have the presence of certain clinical manifestations and Scl-70 antibody, which is known to confer a poor prognosis. These findings support the association between occupational silica exposure and the subsequent development of SSc. Further investigation is required to describe the range of clinical manifestations and disease course, including prognosis and treatment response, in those diagnosed with occupationally induced SSc compared with idiopathic SSc.

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Panels, Jeanne E., and Yong Lak Joo. "Incorporation of Vanadium Oxide in Silica Nanofiber Mats via Electrospinning and Sol-Gel Synthesis." Journal of Nanomaterials 2006 (2006): 1–10. http://dx.doi.org/10.1155/jnm/2006/41327.

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Submicron scale vanadia/silica hybrid nanofiber mats have been produced by electrospinning silica sol-gel precursor containing vanadium oxytriisopropoxide (VOTIP), followed by calcinations at high temperature. The properties of the resulting inorganic hybrid nanofiber mats are compared to those of electrospun pure silica nanofibers. SEM images show fibers are submicron in diameter and their morphology is maintained after calcination. Physisorption experiments reveal that silica nanofiber mats have a high specific surface area of 63 m2/g. FT-IR spectra exhibit Si—O vibrations and indicate the presence of V2O5in the fibers. XPS studies reveal that the ratio of Si to O is close to 0.5 on the surface of fibers and the amount of vanadium on the surface of fibers increases with calcination. XRD diffraction patterns show that silica nanofibers are amorphous and orthorhombic V2O5crystals have formed after calcination. EFTEM images demonstrate the growth of crystals on the surface of fibers containing vanadium after calcination. SEM images of fibers with high-vanadium content (50 mol%V: Si) show that vanadia crystals are mostly aligned along the fiber axis. XPS shows an increase in vanadium contents at the surface, and XRD patterns exhibit an increase in the degree of crystallinity. A coaxial electrospinning scheme has successfully been employed to selectively place V2O5in the skin layer.

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Ta, Van Duong, Tam Trong Nguyen, Thi Ha Lien Nghiem, Hong Nhung Tran, Anh Tu Le, Nguyen Thuan Dao, Phuoc Dinh Duong, and Hanh Hong Mai. "Silica based biocompatible random lasers implantable in the skin." Optics Communications 475 (November 2020): 126207. http://dx.doi.org/10.1016/j.optcom.2020.126207.

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Pilloni, Martina, Guido Ennas, Mariano Casu, Anna Maria Fadda, Francesca Frongia, Francesca Marongiu, Roberta Sanna, Alessandra Scano, Donatella Valenti, and Chiara Sinico. "Drug silica nanocomposite: preparation, characterization and skin permeation studies." Pharmaceutical Development and Technology 18, no. 3 (February 11, 2012): 626–33. http://dx.doi.org/10.3109/10837450.2011.653821.

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Caltabiano, Rosario, Rocco De Pasquale, Eliana Piombino, Giorgia Campo, Ferdinando Nicoletti, Eugenio Cavalli, Katia Mangano, and Paolo Fagone. "Macrophage Migration Inhibitory Factor (MIF) and Its Homologue D-Dopachrome Tautomerase (DDT) Inversely Correlate with Inflammation in Discoid Lupus Erythematosus." Molecules 26, no. 1 (January 1, 2021): 184. http://dx.doi.org/10.3390/molecules26010184.

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Discoid Lupus Erythematosus (DLE) is a chronic cutaneous disease of unknown etiology and of immunoinflammatory origin that is characterized by inflammatory plaques and may lead to disfiguring scarring and skin atrophy. Current treatments are limited, with a large proportion of patients either poorly or not responsive, which makes DLE an unmet medical need. Macrophage migration inhibitory factor (MIF) is the prototype of a pleiotropic family of cytokine that also includes the recently discovered homologue D-dopachrome tautomerase (DDT) or MIF2. MIF and DDT/MIF-2 exert several biological properties, primarily, but not exclusively of a proinflammatory nature. MIF and DDT have been suggested to play a key role in the pathogenesis of several autoimmune diseases, such as multiple sclerosis and type 1 diabetes, as well as in the development and progression of certain forms of cancers. In the present study, we have performed an immunohistochemistry analysis for the evaluation of MIF in DLE lesions and normal skin. We found high levels of MIF in the basal layer of the epidermis as well as in the cutaneous appendage (eccrine glands and sebocytes) of normal skin. In DLE lesions, we observed a significant negative correlation between the expression of MIF and the severity of inflammation. In addition, we performed an analysis of MIF and DDT expression levels in the skin of DLE patients in a publicly available microarray dataset. Interestingly, while these in silico data only evidenced a trend toward reduced levels of MIF, they demonstrated a significant pattern of expression and correlation of DDT with inflammatory infiltrates in DLE skins. Overall, our data support a protective role for endogenous MIF and possibly DDT in the regulation of homeostasis and inflammation in the skin and open up novel avenues for the treatment of DLE.

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Singer, Michael, Herb Srolovitz, Robin Bullick, and André Dufresne. "Foreign Body Granulomatous Reaction Presenting as Systemic Sarcoidosis: A Case Report with Energy-Dispersive Spectroscopy Analysis." Journal of Cutaneous Medicine and Surgery 1, no. 1 (July 1996): 40–44. http://dx.doi.org/10.1177/120347549600100112.

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Background: Sarcoidosis is an immune-mediated idiopathic disorder and is generally thought to be a diagnosis of exclusion. Although researchers have looked at viruses, mycobacteria, and certain chemicals as possible triggers, the initiating antigen remains unidentified. Observations: A 41-year-old black male metal-worker previously diagnosed with systemic sarcoidosis presented with a 6-month history of recurrent, sometimes tender, skin nodules on the lower legs. Chest film, gallium scan, and angiotensin-converting enzyme (ACE) level results supported a diagnosis of systemic sarcoidosis. A biopsy of a lower extremity skin nodule showed confluent non-necrotizing granulomas with irregular birefringent particles in giant cells in a fibrous tissue background suggestive of a silica nodule. Review of a previous bronchial biopsy showed similar foreign body granulomas. Energy-dispersive spectroscopy (EDS) analysis of skin and lung tissue revealed mainly silica, clay (kaolinite), chromium, and aluminum particles that were consistent with the patient's occupational exposure. Conclusions: ACE level and gallium scan may not be specific for sarcoidosis. In certain occupational settings, EDS analysis should be considered before a diagnosis of sarcoidosis is made. This case may provide insight into the etiology of certain presentations labelled as sarcoidosis.

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Lovětinská-Šlamborová, Irena, Petr Holý, Petr Exnar, and Ivana Veverková. "Silica Nanofibers with Immobilized Tetracycline for Wound Dressing." Journal of Nanomaterials 2016 (2016): 1–6. http://dx.doi.org/10.1155/2016/2485173.

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Local antibiotic treatment has its justification for superficial infections. The advantage of this treatment is that the antibiotic has effects on bacterial agent directly at the application site. Skin infections which are intended for the local antibiotic treatment are superficial pyoderma, some festering wounds, burns of second and third degree, infected leg ulcers, or decubitus of second and third degree. Tetracyclines are available topical antibiotics with a broad bacterial spectrum. At present, ointments containing tetracycline are also used for the treatment, which rarely can lead to skin sensitization. In this paper, a development of novel nanofibrous material with immobilized tetracycline is presented. Two different methods of immobilized tetracycline quantification onto silica nanofibers are employed. It was proven that the prevailing part of tetracycline was bound weakly by physisorption forces, while the minor part was covalently bound by NH2groups formed by the preceding functionalization. The silica nanofibers with immobilized tetracycline are promising material for wound dressing applications due to its antibacterial activity; it was proved by tests.

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Ioannis, Michaloudis, and Matthew van Roden. "Spirited Skies project: Silica Aerogel in Art and Design Applications." MRS Advances 2, no. 57 (2017): 3491–97. http://dx.doi.org/10.1557/adv.2017.349.

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ABSTRACTThis comparative study on two interdisciplinary artistic practices aims to improve public perception of scientific research and to facilitate informed decision making regarding climate change and how it affects everyday life. It also hopes to break down (or bridge?) the isolated silos of Art and Science, by emphasizing the role of imagination as a tool of creation and innovation in the new economies of the 21st century. Notwithstanding the ephemeral appearance of the super-light nanomaterial silica aerogel used by Ioannis Michaloudis (Michalous) in his sculptures, the longevity of some of his art seems guaranteed: two works, Bottled Nymph and Noli Me Tangere have been selected to be rocketed to the moon as part of the MoonArk sculpture. The sculptures will be aboard a Space X Falcon 9 rocket launched in 2018 from Cape Kennedy in an Astrobotic Robotic Lunar Mission, and will remain on the moon, potentially, for billions of years. Spirited Skies is a project where we experience by touching other forms of longevity of the ephemeral silica aerogel. Filling double jacketed borosilicate glass vials with aerogel skies and clouds in a unique way, Michaloudis transforms every day’s life trivial objects into art. And whilst Michaloudis is seeding the heavens and landing his artwork onto the moon, a Masters student under his supervision, Matthew van Roden is waxing and waning back here on earth. Van Roden’s material of choice is wax, which he pushes through various artistic disciplines to extrapolate its flesh like qualities.

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El-Toni, Ahmed Mohamed, Shu Yin, and Tsugio Sato. "Enhancement of Calcia Doped Ceria Nanoparticles Performance as UV Shielding Material." Advances in Science and Technology 45 (October 2006): 673–78. http://dx.doi.org/10.4028/www.scientific.net/ast.45.673.

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Calcia-doped ceria is of potential interest as an ultraviolet (UV) radiation blocking material in personal care products because of its excellent UV light absorption property and low catalytic ability for the oxidation of organic materials superior to undoped ceria. The performance of calcia doped ceria needs more enhancement through further control of its oxidation catalytic activity and improvement of its covering ability. In order to reduce the oxidation catalytic activity further, calcia-doped ceria was coated with amorphous silica by means of seeded polymerization technique. Generally, nanoparticles of calcia doped ceria do not provide a good coverage for human skin because of the agglomeration of the nanoparticles. The platy particles are required to enhance the covering ability of calcia doped ceria. This can be accomplished by synthesis of calcia-doped ceria/plate-like material (e.g., potassium lithium titanate (K0.8Li0.27Ti1.73O4) and mica) nanocomposite with subsequent silica coating. Calcia-doped ceria/plate-like material was prepared by soft chemical method followed by silica coating via seeded polymerization technique. Silica coated calcia-doped ceria/plate-like material nanocomposite was characterized by X-ray diffraction, SEM, TEM, XPS and FT-IR.

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Han, Xin, and Juan Wang. "A Novel Method for Fabrication of the Biomimetic Shark-Skin Coating." Advanced Materials Research 239-242 (May 2011): 3014–17. http://dx.doi.org/10.4028/www.scientific.net/amr.239-242.3014.

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The shark-skin effect motivated from the dermal surface morphology of sharks hastens the imitation and manufacture of the non-smooth drag reduction bionic coating based on shark skin. The fabrication of the bionic shark-skin coating with life-sized scale-like microstructure was presented in this paper. Using hot embossing technology, the direct micro replication of the microstructure on shark skin was investigated for the first time. Modeled after the shark skin sample, the negative structure was directly replicated and printed on PMMA flat plate in the hot embossing process, relied on which the bionic shark-skin coating made of silica gel was fabricated in the end. The preliminary experiment results indicate that this method is a high precision, high throughput, high efficiency and low cost way to fabricate bionic microstructure in micron and submicron scale with good repeatability and availability.

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Wang, Meng-Jiao, and Yakov Kutsovsky. "Effect of Fillers on Wet Skid Resistance of Tires. Part I: Water Lubrication Vs. Filler-Elastomer Interactions." Rubber Chemistry and Technology 81, no. 4 (September 1, 2008): 552–75. http://dx.doi.org/10.5254/1.3548220.

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Abstract From results of testing materials using a new filler, it was recognized that the wet skid resistance of tires is determined not only by dynamic properties of the tread compounds, but also by elastohydrodynamic lubrication, especially on the micro scale. By reviewing the basic concepts of friction under dry and wet conditions, and friction coefficients of possible model materials that are at the worn surface of tire tread compounds and road surface, it is inferred that after skid testing under wet conditions, the top skin of the worn surface contains some bare silica for silica-filled compounds, but the carbon black aggregates remain covered by rubber film. This inference is supported by measuring the surface energies of the fillers, analyzing the properties of filled vulcanizates, and direct investigation of worn surface of the compounds after skid test by AFM. The different surface compositions between silica- and carbon black-filled vulcanizates would lead to different effects on micro-elastohydrodynamic lubrication, hence wet skid resistance, which will be the topic of next report of this study.

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Dai, Guyu, Xin Xu, Xiaohong Wu, Xiaolin Lei, Xing Wei, Zhibin Li, Qing Xiao, Renming Zhong, and Sen Bai. "Application of 3D-print silica bolus for nasal NK/T-cell lymphoma radiation therapy." Journal of Radiation Research 61, no. 6 (September 22, 2020): 920–28. http://dx.doi.org/10.1093/jrr/rraa084.

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Abstract The aim of the study was to evaluate the clinical feasibility of a 3D-print silica bolus for nasal NK/T-cell lymphoma radiation therapy. Intensity modulated radiotherapy (IMRT) and volumetric modulated arc therapy (VMAT) plans were designed using an anthropomorphic head phantom with a 3D-print silica bolus and other kinds of bolus used clinically, and the surface dose was measured by a metal oxide semiconductor field-effect transistor (MOSFET) dosimeter. Four nasal NK/T patients with or without 3D-print silica bolus were treated and the nose surface dose was measured using a MOSFET dosimeter during the first treatment. Plans for the anthropomorphic head phantom with 3D-print bolus have more uniform dose and higher conformity of the planning target volume (PTV) compared to other boluses; the homogeneity index (HI) and conformity index (CI) of the VMAT plan were 0.0589 and 0.7022, respectively, and the HI and CI of the IMRT plan were 0.0550 and 0.7324, respectively. The MOSFET measurement results showed that the surface dose of the phantom with 3D-print bolus was >180 cGy, and that of patients with 3D-print bolus was higher than patients without bolus. The air gap volume between the 3D-print bolus and the surface of patients was <0.3 cc. The 3D-print silica bolus fitted well on the patient’s skin, effectively reducing air gaps between bolus and patient surface. Meanwhile, the 3D-print silica bolus provided patients with higher individuation, and improved the conformity and uniformity of the PTV compared to other kinds of boluses.

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Jung, Eui, Xiaoying Hui, Hanjiang Zhu, Alissa Zhang, Wei Wang, Bruce Buchholz, and Howard Maibach. "Effect of iron and silica nanoparticles’ size on in vitro human skin binding and penetration." Toxicology Research and Application 3 (January 1, 2019): 239784731989305. http://dx.doi.org/10.1177/2397847319893054.

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This in vitro skin study determined absorption, diffusion, and binding rates of four [14C]-labeled nanoparticles (NPs): 12 nm Fe3O4, 32 nm Fe3O4@SiO2, 33 nm SiO2, and 78 nm SiO2 in each layer of human cadaver skin. In vitro microdialysis device and flow-through skin diffusion system were used to measure the binding affinity to the stratum corneum (SC) and permeability into/through skin layer of the four NPs with different physical–chemical properties, respectively, in short (30 min) and/or long (24 hours) exposures. Results show that NP size is an important factor affecting NP percutaneous absorption. The 12 nm Fe3O4 NPs reached the SC and viable epidermis; 32 nm Fe3O4@SiO2 core/shell NPs only reached SC. However, 33 nm and 78 nm silica NPs did not permeate SC. Similar patterns were observed for NP binding affinity to SC and dermatopharmacokinetic analysis using the tape stripping method. The binding affinity determination may be a useful method to efficiently screen skin penetration of NPs.

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Kosina, Pavel, Markéta Paloncýová, Alena Rajnochová Svobodová, Bohumil Zálešák, David Biedermann, Jitka Ulrichová, and Jitka Vostálová. "Dermal Delivery of Selected Polyphenols from Silybum marianum. Theoretical and Experimental Study." Molecules 24, no. 1 (December 24, 2018): 61. http://dx.doi.org/10.3390/molecules24010061.

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Silymarin is a well-known standardized extract from the seeds of milk thistle (Silybum marianum L., Asteraceae) with a pleiotropic effect on human health, including skin anticancer potential. Detailed characterization of flavonolignans properties affecting interactions with human skin was of interest. The partition coefficients log Pow of main constitutive flavonolignans, taxifolin and their respective dehydro derivatives were determined by a High Performance Liquid Chromatography (HPLC) method and by mathematical (in silico) approaches in n-octanol/water and model lipid membranes. These parameters were compared with human skin intake ex vivo. The experimental log Pow values for individual diastereomers were estimated for the first time. The replacement of n-octanol with model lipid membranes in the theoretical lipophilicity estimation improved the prediction strength. During transdermal transport, all the studied compounds permeated the human skin ex vivo; none of them reached the acceptor liquid. Both experimental/theoretical tools allowed the studied polyphenols to be divided into two groups: low (taxifolin, silychristin, silydianin) vs. high (silybin, dehydrosilybin, isosilybin) lipophilicity and skin intake. In silico predictions can be usefully applied for estimating general lipophilicity trends, such as skin penetration or accumulation predictions. However, the theoretical models cannot yet provide the dermal delivery differences of compounds with very similar physico-chemical properties; e.g., between diastereomers.

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Lorenzo-Martín, L. Francisco, and Xosé R. Bustelo. "In Silico Analysis of the Age-Dependent Evolution of the Transcriptome of Mouse Skin Stem Cells." Cells 9, no. 1 (January 9, 2020): 165. http://dx.doi.org/10.3390/cells9010165.

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The stem cells located in the hair follicle bulge area are critical for skin regeneration and repair. To date, little is known about the evolution of the transcriptome of these cells across time. Here, we have combined genome-wide expression analyses and a variety of in silico tools to determine the age-dependent evolution of the transcriptome of those cells. Our results reveal that the transcriptome of skin stem cells fluctuates extensively along the lifespan of mice. The use of both unbiased and pathway-centered in silico approaches has also enabled the identification of biological programs specifically regulated at those specific time-points. It has also unveiled hubs of highly transcriptionally interconnected genes and transcriptional factors potentially located at the core of those age-specific changes.

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Silva, Filipa A. L. S., Gonçalo Brites, Isabel Ferreira, Ana Silva, Bruno Miguel Neves, Jorge L. G. F. S. Costa Pereira, and Maria T. Cruz. "Evaluating Skin Sensitization Via Soft and Hard Multivariate Modeling." International Journal of Toxicology 39, no. 6 (August 6, 2020): 547–59. http://dx.doi.org/10.1177/1091581820944395.

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Allergic contact dermatitis is the most frequent manifestation of immunotoxicity in humans with a prevalence rate of 15% to 20% over general population. Skin sensitization is a complex end point that was for a long time being evaluated using animal testing. Great efforts have been made to completely substitute the use of animals and replace them by integrating data from in vitro and in chemico assays with in silico calculated parameters. However, it remains undefined how to make the best use of the cumulative data in such a way that information gain is maximized and accomplished with the fewest number of tests possible. In this work, 3 skin sensitization prediction models were considered: one to discriminate sensitizers from non-sensitizers, considering a 2-level scale; one according to the GHS, considering a 3-level scale; and the other to categorize potency in a 6-level scale, according to available human data. We used a data set of known human skin allergens for which in vitro, in chemico, and in silico descriptors where available to build classifiers based on soft and hard multivariate modeling. Model building, optimization, and refinement resulted in 100% accuracy in distinguishing between sensitizers and non-sensitizers. The same model was able to perform the characterization, in 3 and 6 levels, respectively, with 98.8 and 97.5% accuracy. Combining data from in vitro and in chemico tests with in silico descriptors is relatively simple to implement and some predictors are fitting the adverse outcome pathway for skin sensitization.

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Iyer, Swaminathan, Yaroslav Kievsky, and Igor Sokolov. "Fluorescent silica colloids for study and visualization of skin care products." Skin Research and Technology 13, no. 3 (August 2007): 317–22. http://dx.doi.org/10.1111/j.1600-0846.2007.00231.x.

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Matsuo, Kazuhiko, Sachiko Hirobe, Naoki Okada, and Shinsaku Nakagawa. "Analysis of Skin Permeability and Toxicological Properties of Amorphous Silica Particles." Biological & Pharmaceutical Bulletin 39, no. 7 (2016): 1201–5. http://dx.doi.org/10.1248/bpb.b16-00258.

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Sapino, Simona, Simonetta Oliaro-Bosso, Daniele Zonari, Andrea Zattoni, and Elena Ugazio. "Mesoporous silica nanoparticles as a promising skin delivery system for methotrexate." International Journal of Pharmaceutics 530, no. 1-2 (September 2017): 239–48. http://dx.doi.org/10.1016/j.ijpharm.2017.07.058.

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Li, Cui-E., Shi-An Zhong, Xiao-Jing Li, and Meng Guo. "Silica particles coated with azobenzene-containing photoresponsive molecule-imprinted skin layer." Colloid and Polymer Science 291, no. 9 (March 26, 2013): 2049–59. http://dx.doi.org/10.1007/s00396-013-2944-7.

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Grooten, Yasmine, Aleksandra Sych, Debby Mangelings, and Yvan Vander Heyden. "Comparison of in-silico modelling and reversed-phase liquid chromatographic retention on an octadecyl silica column to predict skin permeability of pharmaceutical and cosmetic compounds." Journal of Pharmaceutical and Biomedical Analysis 201 (July 2021): 114095. http://dx.doi.org/10.1016/j.jpba.2021.114095.

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Fong, Pedro, and Henry H. Y. Tong. "In Silico Prediction of the Cosmetic Whitening Effects of Naturally Occurring Lead Compounds." Natural Product Communications 7, no. 10 (October 2012): 1934578X1200701. http://dx.doi.org/10.1177/1934578x1200701010.

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The identification of tyrosinase inhibitors is important, not only for the treatment of skin hyperpigmentation disorders, such as melasma, but also for the production of cosmetic whitening effects. The aim of this study was the in silico prediction of the naturally occurring lead compounds in three commonly used skin-whitening herbs: Ampelopsis japonica, Lindera aggregata, and Ginkgo biloba. The active ingredients responsible for the whitening effect of these herbs remain largely unknown. The tyrosinase binding affinities and skin permeation, skin irritancy, and corrosive properties of 43 natural constituents of the three herbs were predicted by docking simulations using Surflex-Dock and the QSAR-based Dermal Permeability Coefficient Program (DERMWINTM) and Skin Irritation Corrosion Rules Estimation Tool (SICRET) implemented in Toxtree. Nine constituents of the three herbs were found to have more advanced binding energies than the gold standard whitening agents, arbutin and kojic acid, but 40 were indicative of at least one skin sensitization alert, and many exhibited poor skin permeability. Linderagalactone c and (+)- n-methyllaurotetanine were found to have the strongest prospects for use in topical formulations, as they achieved high predicted tyrosinase binding scores and displayed good skin permeation properties and minimal potential for skin sensitization and irritation.

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Gaware, S., Preetam Bala, Sandip Dhobale, Anand Joshi, Narendra Wagh, Kavita Pal, and Sangeeta N. Kale. "Studies on Control of Erratic Release of Ketoprofen from Commercial Patches for Sustained Pain-Relief Using Silica Microparticles." Nano Hybrids and Composites 12 (November 2016): 88–97. http://dx.doi.org/10.4028/www.scientific.net/nhc.12.88.

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Sustained release of pharmaceutical drug has been a challenge to medical practitioners for a very long time. This is a requirement of anaesthetists, endoscopic surgeons and even dentists. Though commercial bandages are already available for pain and inflammation control, their drug release mechanism is mostly unknown, and is predominantly erratic. This poses a dilemma for medical practitioners, due to which, even if it is recommended to keep patch adhered to skin for 6 hours, it is often replaced in couple of hours or many a times a good amount of undelivered drug remains in the patch and gets wasted. Combining this need for systematic release of drug through such commercial patches and the property of sustained release of drug molecules through mesoporous silica particles, led to an idea for using a coat of Silica Microparticles (SiMPs) on to these patches to achieve controlled and sustained release of drug, mainly Ketoprofen (KP) (a pain-relieving commercial drug). SiMPs were synthesised and coated with pure KP drug on one hand and on another a thin layer of SiMPs was coated on the commercial KP patch. The sustained release studies were done for duration of 6-8 hours. The structural chemistry and the interaction chemistry of the silica-trapped-KP showed that the carboxylic acidic group of hydrogen from KP makes partial bond with silica through weak van-der-Waal forces interaction and efficiency of 75 % of drug loading. The commercial KP patch showed initial burst and later erratic release. However, KP patches upon coating with SiMPs showed controlled release of drug, with the initial burst release and subsequent sustained release in the agar platform-based drug release study. Loose conjugational chemistry, with good bio-availability of SiMPs provides a fine control over the release mechanism, which probably forms a fine mesh-matrix through which the drug slowly percolates. Further, since the particles are not too small, the passage of these particles through the skin-barrier is also less-probable, thereby imparting a facilitative effect for drug passage, in a controlled fashion. Hence a simple strategy is proposed to achieve better medicinal patches for pain-control and better drug efficacy.

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Amamoto, Takaki, Satoshi Hirakawa, Tomofumi Santa, Takashi Funatsu, and Masaru Kato. "Surface modification of silica nanoparticles using 4-aryloxy boron dipyrromethene (BODIPY) enhances skin permeation." Journal of Materials Chemistry B 4, no. 47 (2016): 7676–80. http://dx.doi.org/10.1039/c6tb02188c.

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Adamska, Elżbieta, Karolina Niska, Anna Wcisło, and Beata Grobelna. "Characterization and Cytotoxicity Comparison of Silver- and Silica-Based Nanostructures." Materials 14, no. 17 (August 31, 2021): 4987. http://dx.doi.org/10.3390/ma14174987.

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Core-shell structures are the most common type of composite material nanostructures due to their multifunctional properties. Silver nanoparticles show broad antimicrobial activity, but the safety of their utilization still remains an issue to tackle. In many applications, the silver core is coated with inorganic shell to reduce the metal toxicity. This article presents the synthesis of various materials based on silver and silica nanoparticles, including SiO2@Ag, Ag@SiO2, and sandwich nanostructures—Ag@SiO2@Ag—and the morphology of these nanomaterials based on transmission electron microscopy (TEM), UV-Vis spectroscopy, and FT-IR spectroscopy. Moreover, we conducted the angle measurements due to the strong relationship between the level of surface wettability and cell adhesion efficiency. The main aim of the study was to determine the cytotoxicity of the obtained materials against two types of human skin cells—keratinocytes (HaCaT) and fibroblasts (HDF). We found that among all the obtained structures, SiO2@Ag and Ag@SiO2 showed the lowest cell toxicity and very high half-maximal inhibitory concentration. Moreover, the measurements of the contact angle showed that Ag@SiO2 nanostructures were different from other materials due to their superhydrophilic nature. The novel approach presented here shows the promise of implementing core-shell type nanomaterials in skin-applied cosmetic or medical products.

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H., Abd El-Wahab, Farouk Abd El-Monem, Naser M.A., Hussain A.I., El-Shahat H. A. Nashy, and Lin L. "Novel tanning agent based on silica-nanocomposite emulsion polymers." Pigment & Resin Technology 49, no. 4 (April 11, 2020): 283–94. http://dx.doi.org/10.1108/prt-12-2019-0113.

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Purpose The purpose of this paper is devoted to application of the emulsion polymer of poly(methyl methacrylate-co-butyl acrylate) prepared with in situ nano-silica as a novel tanning agent of hide to partly or totally replace chrome salt and to improve physical, thermal and mechanical properties of the tanned leather and to reduce the environmental impact of chrome tanning effluent. Design/methodology/approach Polymer/nano-silica hybrid emulsions were prepared via in situ seed emulsion polymerisation. The prepared polymers were characterised for solid content, molecular weight, viscosity, drying time, minimum film-forming temperature (MFFT) and microstructures (via transmission electron microscopy). The mechanical, thermal and surface morphological (by scanning electron microscope) properties of the treated samples were also investigated. The influences of the increase in the content of organic nano-silica on the properties of the tanned leather are discussed. Findings It was found that the viscosity, the particle size and the solid content of the prepared polymers increased as the content of the nano-silica increased while gloss and drying time of the resulting polymer film decreased. Tanning buffalo hide by Polymer F (containing a high content of nano-silica) gave desirable properties in terms of tensile strength, thermal stability and shrinkage temperature. Research limitations/implications This paper discusses the preparation and the characterisation of emulsion polymers with in situ nano-silica and their application in tanning process to enhance and improve the leather quality, as well as reduce the use of chrome tanning materials and consequently chrome tanning waste. Practical implications The tanned leather showed an improvement of physico-mechanical properties and enhancement of thermal stability. Furthermore, the tanned leather has uniform colour, softness and firmness of grain. All these promising results provide evidence to support the applicability of the prepared co-polymer/nano-silica emulsions as an efficient tanning agent that also provides lubricating properties for leather. Originality/value Since May 2015, REACH Annex XVII restricts Cr(VI) in leather articles or leather parts of articles that come into contact with skin to a concentration of less than 3 mg/kg. Cases of discovery of Cr(VI) in leather papers have been reported by the European rapid alert system on dangerous consumer products (RAPEX). The emulsion poly (methyl methacrylate-co-butyl acrylate) with in situ nano-silica that has been developed via the study reported in this paper is one of the better technologies for the reduction of chromium ratio used in tanning industry.

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Marfania, Cillia. "Imobilisasi kulit Lengkeng (euphoria longan lour) terhadap penyerapan ion logam Kadmium." CHEMPUBLISH JOURNAL 4, no. 1 (July 19, 2019): 44–51. http://dx.doi.org/10.22437/chp.v4i1.6915.

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The use of longan skin biosorbents has been shown to reduce environmental pollution caused by heavy metals. Because it has an active site and its facial pores can support the absorption process, it is inexpensive and environmentally friendly. However, the ability of longan skin in absorption has several limitations such as particles that are lightweight, easily damaged and of low specific gravity. To overcome this, various methods have been carried out, one of which is the immobilization of sodium silica. The biosorption method used was the bath method. The results of this study, optimum absorption of Cd metal ions occurred at a concentration of 250 ppm, with a contact time of 120 minutes and a speed of 250 rpm.

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Hou, Xiaochun, Shiying Liu, Min Wang, Christian Wiraja, Wei Huang, Peggy Chan, Timothy Tan, and Chenjie Xu. "Layer-by-Layer 3D Constructs of Fibroblasts in Hydrogel for Examining Transdermal Penetration Capability of Nanoparticles." SLAS TECHNOLOGY: Translating Life Sciences Innovation 22, no. 4 (June 20, 2016): 447–53. http://dx.doi.org/10.1177/2211068216655753.

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Nanoparticles are emerging transdermal delivery systems. Their size and surface properties determine their efficacy and efficiency to penetrate through the skin layers. This work utilizes three-dimensional (3D) bioprinting technology to generate a simplified artificial skin model to rapidly screen nanoparticles for their transdermal penetration ability. Specifically, this model is built through layer-by-layer alternate printing of blank collagen hydrogel and fibroblasts. Through controlling valve on-time, the spacing between printing lines could be accurately tuned, which could enable modulation of cell infiltration in the future. To confirm the effectiveness of this platform, a 3D construct with one layer of fibroblasts sandwiched between two layers of collagen hydrogel is used to screen silica nanoparticles with different surface charges for their penetration ability, with positively charged nanoparticles demonstrating deeper penetration, consistent with the observation from an existing study involving living skin tissue.

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Shen, Jie, Lambros Kromidas, Terry Schultz, and Sneha Bhatia. "An in silico skin absorption model for fragrance materials." Food and Chemical Toxicology 74 (December 2014): 164–76. http://dx.doi.org/10.1016/j.fct.2014.09.015.

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Ranade, Dr Siddhesh Ramakant, and Dr Shankar Hulekar. "Common skin disease “corns” with effective homeopathic medicine Silicea." International Journal of Homoeopathic Sciences 5, no. 2 (April 1, 2021): 09–10. http://dx.doi.org/10.33545/26164485.2021.v5.i2a.354.

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Journal articles on the topic 'Silica skins'

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