Fabrication of Wettability-Patterned Surface for Cellular Micropatterning Using Step-Wise Ion Beam Processing

In this study, the fabrication of a wettability patterned surface for cellular micropatterning was investigated using step-wise ion beam processing. A perfluorinated poly(ethylene-co-propylene) (FEP) film was first irradiated using accelerated Xe+ ions with 100 keV of energy at the low current density of 1 μA/cm² over the entire surface. Second, its confined regions were irradiated at the higher current density of 15 μA/cm² at various ion fluences through the pattern mask to generate patterns with big differences in wettability. From the analytic results, it was clearly verified that the step-wise irradiation induced effective chemical and morphological changes on the FEP surface, resulting in the successful formation of well-defined micropatterns with relatively hydrophilic and superhydrophobic surfaces. Moreover, the results of in-vitro cell culture showed well-resolved formation of 200 μm cell micropatterns on the wettability patterned FEP surface due to the individual effects of the relatively hydrophilic and superhydrophobic properties on the cell adhesiveness and proliferation.

Inkjet-Printed Carbon Nanotubes for Fabricating a Spoof Fingerprint on Paper

A spoof fingerprint was fabricated on paper and applied for a spoofing attack to unlock a smartphone on which a capacitive array of sensors had been embedded with a fingerprint recognition algorithm. Using an inkjet printer with an ink made of carbon nanotubes (CNTs), we printed a spoof fingerprint having an electrical and geometric pattern of ridges and furrows comparable to that of the real fingerprint. With this printed spoof fingerprint, we were able to unlock a smartphone successfully; this was due to the good quality of the printed CNT material, which provided electrical conductivities and structural patterns similar to those of the real fingerprint. This result confirms that inkjet-printing CNTs to fabricate a spoof fingerprint on paper is an easy, simple spoofing route from the real fingerprint and suggests a new method for outputting the physical ridges and furrows on a two-dimensional plane.

Cross-Linked Polymersomes with Reversible Deformability and Oxygen Transportability

Polymersomes are of interest as nanocarriers due to their physical and chemical robustness, which arises from the macromolecular nature of their block copolymer components. However, the physical robustness of polymersomes impairs transmembrane diffusion and responsiveness to mechanical forces. Polymer nanocarriers that can reversibly deform under stress while maintaining structural integrity and transmembrane diffusivity are desired for development of gas transport vehicles. Here, we report polymersomes composed of amphiphilic block copolymers containing polydimethylsiloxane with side-chain pendant vinyl groups. A reversibly deformable polymersome compartmentalizing membrane was obtained by cross-linkage of PEG- b-poly(dimethyl- r-methylvinyl)silane in a self-assembled bilayer via photoradical generation in aqueous media. The covalently cross-linked polymersomes exhibited superior physical robustness compared to unlinked polymersomes while maintaining deformability under stress. Transmembrane oxygen diffusion was confirmed when lumen-encapsulated Zn-porphyrin generated singlet O₂ under irradiation, and the anthracene-9,10-dipropionic acid O₂ quencher was consumed. Polymersome-encapsulated hemoglobin bound oxygen reversibly, indicating the polymersomes could be used as O₂ carriers that reversibly deform without sacrificing structural integrity or oxygen transportability.

Affordable Fabrication of Conductive Electrodes and Dielectric Films for a Paper-based Digital Microfluidic Chip

In order to fabricate a digital microfluidic (DMF) chip, which requires a patterned array of electrodes coated with a dielectric film, we explored two simple methods: Ballpoint pen printing to generate the electrodes, and wrapping of a dielectric plastic film to coat the electrodes. For precise and programmable printing of the patterned electrodes, we used a digital plotter with a ballpoint pen filled with a silver nanoparticle (AgNP) ink. Instead of using conventional material deposition methods, such as chemical vapor deposition, printing, and spin coating, for fabricating the thin dielectric layer, we used a simple method in which we prepared a thin dielectric layer using pre-made linear, low-density polyethylene (LLDPE) plastic (17-μm thick) by simple wrapping. We then sealed it tightly with thin silicone oil layers so that it could be used as a DMF chip. Such a treated dielectric layer showed good electrowetting performance for a sessile drop without contact angle hysteresis under an applied voltage of less than 170 V. By using this straightforward fabrication method, we quickly and affordably fabricated a paper-based DMF chip and demonstrated the digital electrofluidic actuation and manipulation of drops.

Antiviral activity of hypothiocyanite produced by lactoperoxidase against influenza A and B viruses and mode of its antiviral action

Hypothiocyanite (OSCN-) is a natural component of human saliva and is produced by the lactoperoxidase (LPO)/thiocyanate/hydrogen peroxide (H2O2) system. OSCN- has been previously shown to exhibit antiviral activity against influenza viruses (IFV) A/H1N1/2009 and A/H1N2/2009 in vitro as well as antimicrobial and antifungal activities. We elucidated the antiviral activity of OSCN- against both IFV types A and B and the mode of its antiviral action. OSCN- was produced constantly at 900 ± 200 μmol/l in Na3PO4 buffer solution containing NaSCN and LPO in the presence of H2O2 as an original OSCN- solution. In a plaque reduction assay, IFV A/PR/8/34 (H1N1), A/Fukushima/13/43 (H3N2), B/Singapore/222/97, and B/Fukushima/15/93 were exposed to various concentrations of OSCN- for 0 to 30 min before adsorption to MDCK cells, and plaque formation was examined. OSCN- exhibited significant similar antiviral activities against all four viruses without cytotoxicity, and the EC50 values for them were from 57 ± 16 to 148 ± 27 μmol/l regardless of the exposure times. The exposure of MDCK cells to OSCN- before viral adsorption did not affect its anti-IFV activity (EC50: more than 450 μmol/l), but the exposure after viral adsorption affected it moderately (EC50: 380 ± 40 μmol/l). Moreover, the exposure of virus particles to OSCN- at 450 μmol/l did not affect the hemagglutinin activity of IFV in hemagglutination inhibition assay. These results suggest that the attachment of OSCN- to the viral envelope critically contributes to the mode of antiviral action of OSCN- without interfering with viral adsorption. Keywords: hypothiocyanite; influenza virus type A; influenza virus type B; lactoperoxidase; antiviral activity.

High prevalence of cognitive impairment among students near mount Merapi: a case study

This descriptive, cross-sectional study illustrates the high prevalence of intellectual impairment among students at the Kanisius Prontakan primary school near Mt. Merapi, one of the most active volcanic mountains in Indonesia. To determine the possible cause of these abnormal cognitive impairments, we considered and investigated the threats to society and the environment of the frequent volcanic eruptions, as well as the effects of malnutrition due to extreme poverty, in that area. The results showed that intellectual impairment and stunting were remarkably common among the students, with 10.7% of the students showing sigma of intellectual impairment and 96.4% showing signs of stunting. No noticeable chemical problems due to the volcanic activity were found in the drinking water, and no causes of such disorders other than poor nutrition due to poverty were found. Nevertheless, our results provide information on the high prevalence of health problems being experienced by children living in one of the most isolated and underdeveloped volcano mountain areas in Indonesia and draws attention to the severe effects of malnutrition on the development of those children.

Effects of Silicone Oil on Electrowetting to Actuate a Digital Microfluidic Drop on Paper

The effects of an immiscible, lubricating polydimethylsiloxane fluid, referred to as silicone oil, on the static deformation and on the dynamic motion of a water drop on paper induced by electrowetting were investigated. The deformation of a drop on a hydrophobic film of amorphous fluoropolymers top-coated with less hydrophobic silicone oil was much more predictable, reversible and reproducible than on the uncoated surface. In the dynamic tribological experiment for a sliding drop along an inclined surface, a significant decrease in the friction coefficient, with an unexpected dependency of the contact area, was observed. Based on the curve fitting analysis, the shear stress and the net friction force were estimated quantitatively. Because of the tribological effect and the reduced shear friction force of the oil film, the static and the dynamic electrowetting states of the water drop were enhanced.

Electric Heating Performance of Pyrolyzed Photoresist Films Prepared by Proton Irradiation and Pyrolysis

In this study, pyrolyzed photoresist films (PPFs) were prepared using commercial SU8 photoresist by proton irradiation and pyrolysis. SU8 thin films were irradiated with high-energy proton ions and then pyrolyzed in a tube furnace at 1000 °C under inert atmosphere. The carbonization yield of the PPFs increased with an increasing fluence due to the formation of more crosslinked network structures at a higher fluence. The electrical resistance decreased with an increasing fluence due to the higher remaining thickness and carbonization yield at a higher fluence. Therefore, the PPFs prepared at 1 × 1016 ions/cm2 showed the maximum temperature of 150 °C at 20 V and a high electric power efficiency of 1.57 mW/°C.

Preparation of Conductive Carbon Films from Novolac Resins by Ion Beam Irradiation and Carbonization

In this study, thin carbon films with good electrical properties were prepared using commercial novolac resins by ion beam irradiation and carbonization. Novolac films were irradiated with ion beams and then carbonized under inert atmosphere. Based on the FTIR and UV results, the novolac resins were found to be crosslinked by ion beam irradiation without any additives. The Raman and XRD results indicate that carbon films with pseudo-graphitic structures were formed by carbonization of the ion beam irradiated novolac films. The sheet resistance of the prepared carbon films decreased to 1.35 × 102 Ω/ with an increasing fluence. The prepared carbon films showed a good electrical conductivity of ∼2.34 × 102 S/cm.

Interleukin-17A negatively regulates lymphangiogenesis in T helper 17 cell-mediated inflammation

During inflammation lymphatic vessels (LVs) are enlarged and their density is increased to facilitate the migration of activated immune cells and antigens. However, after antigen clearance, the expanded LVs shrink to maintain homeostasis. Here we show that interleukin (IL)-17A, secreted from T helper type 17 (T_H17) cells, is a negative regulator of lymphangiogenesis during the resolution phase of T_H17-mediated immune responses. Moreover, IL-17A suppresses the expression of major lymphatic markers in lymphatic endothelial cells and decreases in vitro LV formation. To investigate the role of IL-17A in vivo, we utilized a cholera toxin-mediated inflammation model and identified inflammation and resolution phases based on the numbers of recruited immune cells. IL-17A, markedly produced by T_H17 cells even after the peak of inflammation, was found to participate in the negative regulation of LV formation. Moreover, blockade of IL-17A resulted in not only increased density of LVs in tissues but also their enhanced function. Taken together, these findings improve the current understanding of the relationship between LVs and inflammatory cytokines in pathologic conditions.

Environmental and health effects of the herbicide glyphosate

The herbicide glyphosate, N-(phosphonomethyl) glycine, has been used extensively in the past 40years, under the assumption that side effects were minimal. However, in recent years, concerns have increased worldwide about the potential wide ranging direct and indirect health effects of the large scale use of glyphosate. In 2015, the World Health Organization reclassified glyphosate as probably carcinogenic to humans. A detailed overview is given of the scientific literature on the movement and residues of glyphosate and its breakdown product aminomethyl phosphonic acid (AMPA) in soil and water, their toxicity to macro- and microorganisms, their effects on microbial compositions and potential indirect effects on plant, animal and human health. Although the acute toxic effects of glyphosate and AMPA on mammals are low, there are animal data raising the possibility of health effects associated with chronic, ultra-low doses related to accumulation of these compounds in the environment. Intensive glyphosate use has led to the selection of glyphosate-resistant weeds and microorganisms. Shifts in microbial compositions due to selective pressure by glyphosate may have contributed to the proliferation of plant and animal pathogens. Research on a link between glyphosate and antibiotic resistance is still scarce but we hypothesize that the selection pressure for glyphosate-resistance in bacteria could lead to shifts in microbiome composition and increases in antibiotic resistance to clinically important antimicrobial agents. We recommend interdisciplinary research on the associations between low level chronic glyphosate exposure, distortions in microbial communities, expansion of antibiotic resistance and the emergence of animal, human and plant diseases. Independent research is needed to revisit the tolerance thresholds for glyphosate residues in water, food and animal feed taking all possible health risks into account.

Formation of Multi-Component Extracellular Matrix Protein Fibers

The extracellular matrix (ECM) consists of polymerized protein monomers that form a unique fibrous network providing stability and structural support to surrounding cells. We harnessed the fibrillogenesis mechanisms of naturally occurring ECM proteins to produce artificial fibers with a heterogeneous protein makeup. Using ECM proteins as fibril building blocks, we created uniquely structured multi-component ECM fibers. Sequential incubation of fibronectin (FN) and laminin (LAM) resulted in self-assembly into locally stacked fibers. In contrast, simultaneous incubation of FN with LAM or collagen (COL) produced molecularly stacked multi-component fibers because both proteins share a similar assembly mechanism or possess binding domains specific to each other. Sequential incubation of COL on FN fibers resulted in fibers with sandwiched layers because COL molecules bind to the external surface of FN fibers. By choosing proteins for incubation according to the interplay of their fibrillogenesis mechanisms and their binding domains (exposed when they unfold), we were able to create ECM protein fibers that have never before been observed.

Synergy between ultrasonication and a polymer matrix in reducing particle size of molecular explosives during crystallization

A molecular explosive was crystallized inside the polymer matrix by quenching while applying ultrasound.

A multi-throughput multi-organ-on-a-chip system on a plate formatted pneumatic pressure-driven medium circulation platform

This paper reports a multi-throughput multi-organ-on-a-chip system formed on a pneumatic pressure-driven medium circulation platform with a microplate-sized format as a novel type of microphysiological system. The pneumatic pressure-driven platform enabled parallelized multi-organ experiments (i.e. simultaneous operation of multiple multi-organ culture units) and pipette-friendly liquid handling for various conventional cell culture experiments, including cell seeding, medium change, live/dead staining, cell growth analysis, gene expression analysis of collected cells, and liquid chromatography-mass spectrometry analysis of chemical compounds in the culture medium. An eight-throughput two-organ system and a four-throughput four-organ system were constructed on a common platform, with different microfluidic plates. The two-organ system, composed of liver and cancer models, was used to demonstrate the effect of an anticancer prodrug, capecitabine (CAP), whose metabolite 5-fluorouracil (5-FU) after metabolism by HepaRG hepatic cells inhibited the proliferation of HCT-116 cancer cells. The four-organ system, composed of intestine, liver, cancer, and connective tissue models, was used to demonstrate evaluation of the effects of 5-FU and two prodrugs of 5-FU (CAP and tegafur) on multiple organ models, including cancer and connective tissue.

The importance of dermoscopy for the diagnosis of acquired bilateral telangiectatic macules: the angioid streak pattern reveals underlying chronic liver disease

BACKGROUND

Acquired bilateral telangiectatic macules (ABTM) are a newly recognized disease entity, which manifest as multiple telangiectatic pigmented macules confined mostly to the upper arms.

OBJECTIVES

To evaluate clinical and dermoscopic features in a group of 50 patients with ABTM and to determine the diagnostic usefulness of dermoscopy in ABTM.

METHODS

Patients were selected from two tertiary teaching hospitals in Korea [Pusan National University Hospitals (Busan and Yangsan)]. Fifty patients (41 males and 9 females; mean age 48.1 years; range 26-78 years) with ABTM were included in the study. The dermoscopic findings were graded using a 4-point scale: none (0), mild (1), moderate (2) and severe (3). In addition, the results of 23 patients with and 27 patients without chronic liver disease (CLD) were compared to determine whether the presence of CLD affects dermoscopic findings.

RESULTS

Three distinct dermoscopic patterns were observed; brown pigmentations, telangiectasia (linear-irregular vessels) and an angioid streak pattern. Brown pigmentation in the group without CLD had higher severity score than those in CLD group (mean score: 2.00 vs. 1.48, P = 0.033). However, mean telangiectasia severity score was higher in the CLD group (2.14 vs. 1.39, P < 0.001). The angioid streak pattern was more severe and more common in patients with CLD than in those without [1.37 vs. 0.35 (P < 0.001) and 63.0% vs. 26.1%, respectively].

CONCLUSIONS

Detailed observations with dermoscopy can provide first clues of the presence of ABTM and underlying chronic liver disease.

Paper-Based Bimodal Sensor for Electronic Skin Applications

We present the development of a flexible bimodal sensor using a paper platform and inkjet printing method, which are suited for low-cost fabrication processes and realization of flexible devices. In this study, we employed a vertically stacked bimodal device architecture in which a temperature sensor is stacked on top of a pressure sensor and operated on different principles, allowing the minimization of interference effects. For the temperature sensor placed in the top layer, we used the thermoelectric effect and formed a closed-loop thermocouple composed of two different printable inks (conductive PEDOT:PSS and silver nanoparticles on a flexible paper platform) and obtained temperature-sensing capability over a wide range (150 °C). For the pressure sensor positioned in the bottom layer, we used microdimensional pyramid-structured poly(dimethylsiloxane) coated with multiwall carbon nanotube conducting ink. Our pressure sensor exhibits a high-pressure sensitivity over a wide range (100 Pa to 5 kPa) and high-endurance characteristics of 10⁵. Our 5 × 5 bimodal sensor array demonstrates negligible interference, high-speed responsivity, and robust sensing characteristics. We believe that the material, process, two-terminal device, and integration scheme developed in this study have a great value that can be widely applied to electronic skin.

HIV Peptide-Mediated Binding Behaviors of Nanoparticles on a Lipid Membrane

The bioinspired design of ligands for nanoparticle coating with remarkable precision in controlling anisotropic connectivity and with universal binding efficiency to the membrane has made a great impact on nanoparticle self-assembly. We utilize the HIV-1-derived trans-activator of transcription peptide (TAT), a member of the cell-penetrating peptides, as a soft shell coating on gold nanoparticles (GNPs) and characterize TAT pepide-mediated binding behaviors of GNPs on the lipid membrane. Whereas the peptides enable GNPs to firmly attach to the membrane, the binding structures are driven by two electrostatic forces: the interparticle peptide repulsion and the peptide-membrane attraction. Although transmission electron microscopy images showed that the densities of membrane-embedded GNPs were almost equal, X-ray reflectivity revealed a significant difference in binding structures of GNPs along the surface normal upon the increase of charge densities (ϕ) of the membrane. In particular, GNPs were densely suspended at ϕ = 70% while they adopted an additional well-defined layer underneath the membrane at ϕ = 100%, in addition to a translocation of the initially bound particles into the membrane. The observed behaviors of GNPs manifest a 3D to 2D transformation of the self-assembled structures from the diffused state to the closely packed state with the increase in the charge density of the membrane. The present study also provides insights on the binding mechanisms of the cell-penetrating peptide-coated nanoparticles to the lipid membranes, which is a common theme of delivery systems in pharmaceutical research.

Enhanced Th2 cell differentiation and function in the absence of Nox2

BACKGROUND

Patients with chronic granulomatous disease (CGD), whom inherit abnormal function of NADPH oxidase 2 (Nox2), suffer from hyperinflammatory responses in lung as well as bacterial and fungal infection. There have been studies to reveal the function of Nox2 in hyperinflammatory diseases, especially in asthma, but the exact role of Nox2 in asthma is still unclear and controversial. Therefore, we attempted to clarify the exact role of Nox2 in asthma, using various experimental asthma models.

METHODS

Asthma phenotypes were analyzed in response to various allergen-induced experimental asthma using Nox2-deficient mice and recombinase gene-activating-1-deficient mice. To understand the underlying mechanisms of exaggerated Th2 effector functions, we investigated the degree of T-cell activation, levels of activation-induced cell death (AICD), and regulatory T (Treg)-cell differentiation in Nox2-deficient T cells.

RESULTS

Asthma phenotypes were increased through enhanced Th2 differentiation and function in Nox2-null mice regardless of dose and route of various allergens. Nox2-deficient T cells also showed hyperactivation, reduced AICD, and diminished Treg-cell differentiation through increased AKT phosphorylation (T308/S473) and enhanced mitochondrial ROS production.

CONCLUSION

Our findings indicate that Nox2 deficiency results in exaggerated experimental asthma, which is caused by enhanced Th2 effector function in a T-cell-intrinsic manner.

Self-assembling characteristics of amphiphilic zwitterionic brush random copolymers at the air–water interface

Amphiphilic zwitterionic brush random copolymers bearing sulfobetaine groups at the bristle ends underwent segregation at the air–water interface, always forming only the Langmuir monolayer structure rather than any other structures.

Anomalies in the Optical Index of Refraction of Spun Cast Polystyrene Thin Films

We used x-ray reflectivity in combination with optical ellipsometry to measure the optical index of refraction, n, in thin spun cast polystyrene films. We have found that n is independent of the molecular weight, but is a sharp function of the film thickness for films less than 100 nm. In all cases the deviation from the bulk, Δ n, is negative and varies linearly with wavelength in the visible region. The magnitude of Δ n, was found to be as large as 0.25 for films 7 nm thick. The bulk index of refraction was recovered in all films after annealing for2habove Tg at 160 °C. X-ray reflectivity measurements of the scattering critical angle show minimal density deviations from the bulk (less than 0.5%) between the annealed and unannealed films. Consequently the large molecular-weight-independent value of Δ n is interpreted as being due to a radially symmetric segmental orientation induced by the spinning process.

Semiconductor Photonic Nanocavity on a Paper Substrate

Direct integration of semiconductor photonic nanocavities with paper substrates is demonstrated for the first time. 1D photonic crystal nanocavities successfully show lasing action on paper substrates. The device has great synergy as a sensor because paper has good wicking ability while a photonic crystal cavity has high figure of merit. The research provides a platform for eco-friendly and sustainable devices.

Simple and Biocompatible Ion Beam Micropatterning of a Cell-Repellent Polymer on Cell-Adhesive Surfaces to Manipulate Cell Adhesion

In this paper, the simple and biocompatible micropatterning of cell-repellent poly(N-isopropylacrylamide) (PNIPAAm) on a cell-adhesive substrate by ion beam micropatterning to control cell adhesion is described. Cell-repellent PNIPAAm films spin-coated on cell-adhesive tissue culture polystyrene (TCPS) substrates were selectively irradiated by energetic proton ions at various fluences through a pattern mask, and subsequently developed to create the micropatterns of PNIPAAm. Well-defined negative-type PNIPAAm micropatterns were successfully created on the TCPS substrates at fluences higher than 5 x 10¹⁴ ions/cm², and their chemical properties were dependent on the fluence. Moreover, based on the results of the protein adsorption and in-vitro cell culture tests, 200 µm well-defined micropatterns of mammalian cells were clearly formed on the PNIPAAm-micropatterned TCPS substrates though the preferential adsorption and growth of cells on the TCPS regions due to the strong cell-repellency of PNIPAAm.

Mechanical stimuli responsive and highly elastic biopolymer/nanoparticle hybrid microcapsules for controlled release

Mechanical stimulus is one of the universally accessible physical ways of triggering the drug release from their carriers. Hollow microcapsules made of polyelectrolyte multilayers by conventional methods are not elastic enough to respond to a large and repetitive mechanical deformation. Here, hybrid hollow capsules comprising alternating layers of inorganic colloidal particles and biopolymers were prepared by the layer-by-layer approach followed by freezing-assisted crosslinking of polymer layers. The size of the capsule was controllable by the size of sacrificial cores. These hybrid capsules were mechanically more stable and recover faster than polyelectrolyte capsules, and could be recovered elastically even after large and repetitive deformation up to 98% relative to their original dimensions. Drugs in a wide range of molecular weight up to 70 kDa M_w could be loaded into the hollow hybrid microcapsules and the release of loaded contents from these hybrid capsules could be controlled through the deformation by applying a weak force such as a finger pressing on them. Mechanical stimuli-responsive delivery of model drugs was demonstrated on a monolayer of these hybrid capsules.

Effects of cardiolipin on membrane morphology: a Langmuir monolayer study

Cardiolipin (CL) is a complex phospholipid that is specifically found in mitochondria. Owing to the association of the CL levels with mitochondrial physiopathology such as in Parkinson's disease, we study the molecular effect of CL on membrane organization using model Langmuir monolayer, fluorescence microscopy, and x-ray reflectivity. We find that the liquid-expanded phase in membranes increases with increasing CL concentration, indicating an increase in the elasticity of the mixed membrane. The Gibbs excess free energy of mixing indicates that the binary monolayer composed of CL and DPPC is most thermodynamically stable at ΦCL = 10 mol%, and the stability is enhanced when the surface pressure is increased. Additionally, when ΦCL is small, the expansion of the membrane with increasing CL content was slower at higher surface pressure. These abnormal results are indicative of a folding structure being present before a collapsing structure, which was confirmed by using fluorescence microscopy and was characterized by using x-ray reflectivity with the electron density profile along the membrane's surface normal.