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The tissue-engineered vascular graft (TEVG) is a technology used to recreate a blood vessel by using vascular cells and scaffolds, which is a promising approach as a feasible alternative for small-diameter blood vessel replacement.

A surface electromyogram (sEMG) electrode collects electrical currents generated by neuromuscular activity by a noninvasive technique on the skin. It is particularly attractive for wearable systems for various human activities and health care monitoring. However, it remains challenging to discriminate EMG signals from isotonic (concentric/eccentric) and isometric movements. By applying nanotechnology, we provide a coiled carbon nanotube (CNT) yarn-integrated sEMG device to overcome sEMG-based motion recognition. When the arm was contracted at different angles, the sEMG-derived root mean square amplitude signals were constant regardless of the angle of the moving arm. However, the coiled CNT yarn-derived open circuit voltage (OCV) signals proportionally increased when the arm's angle increased, and presented negative and positive values depending on the moving direction of the arm. Moreover, isometric contraction is characterized by the onset of EMG signals without an OCV signal, and isotonic contraction is determined by both EMG signals and OCV signals. Taken together, the integration of EMG and coiled CNT yarn electrodes provides complementary information, including the strength, direction, and degree of muscle movement. Therefore, we suggest that our system has high potential as a wearable system to monitor human motions in industrial and human system applications.

Extramedullary myelopoiesis occurs commonly in tumor-bearing animals and is known to lead to accumulation of peripheral myeloid-derived suppressor cells (MDSC), which play an important role in immune escape. However, the cellular and molecular mechanisms by which tumors induce extramedullary myelopoiesis are poorly understood. In this study, we found that osteopontin expressed by tumor cells enhances extramedullary myelopoiesis in a CD44-dependent manner through the Erk1/2–MAPK pathway. Osteopontin-mediated extramedullary myelopoiesis was directly associated with increased MDSCs in tumor-bearing hosts. More importantly, osteopontin silencing in tumor cells delayed both tumor growth and extramedullary myelopoiesis, while the same treatment did not affect tumor growth in vitro. Finally, treatment with an antibody against osteopontin inhibited tumor growth and synergized with cell-based immunotherapeutic vaccines in mediating antitumor immunity. Our findings unveil a novel immunosuppressive role for tumor-derived osteopontin and offer a rationale for its therapeutic targeting in cancer treatment. Cancer Res; 74(22); 6705–16. ©2014 AACR.

Supplemental data. Supplementary method, Supplementary figure legends and Supplementary figures 1-9. Supplementary figure 1. Gating strategies for the flow cytometric analysis. Supplementary figure 2. Changes of MDSCs, lymphoid cells and lymphoid progenitor cells in the CT26 TBM. Supplementary figure 3. Accumulated MDSCs in MC38 TBM. Supplementary figure 4. Increased osteopontin in MC38 TBM. Supplementary figure 5. In vivo proliferation and apoptosis of tumors. Supplementary figure 6. Changes of sub-populations of LK cells. Supplementary figure 7. Induction of extramedullary myelopoiesis by osteopontin from malignant tumor cells in the tumor microenvironment. Supplementary figure 8. The role of osteopontin in LK cell migration and MDSC survival. Supplementary figure 9. Osteopontin-induced LK cell proliferation was mediated by the CD44-ERK/MAPK signaling pathway.

Inertial sensors are devices that can monitor inertial movements, such as linear acceleration and angular motions, in industrial and human systems. For portable and wearable applications, inertial sensors must be self-powered and miniaturized. In this article, we report a self-powered inertial sensor with high accuracy based on carbon nanotube (CNT) yarn. By harvesting the mechanical energy of a coiled CNT yarn, our inertial sensor can detect inertial movements without the need for external power. For practical applications, the sensor can monitor various inertial movements, such as vibrations, external impacts, tilting, and body motions (squatting, walking, running, and jumping motions). These findings suggest that the self-powered inertial sensor exhibits the advantages of portability and wearability in industrial and human system applications.

The carbon nanotube (CNT) yarn supercapacitor has high potential for in vivo energy storage because it can be used in aqueous environments and stitched to inner parts of the body, such as blood vessels. The biocompatibility issue for frequently used pseudocapacitive materials, such as metal oxides, is controversial in the human body. Here, we report an implantable CNT yarn supercapacitor inspired by the cellular redox system. In all living cells, nicotinamide adenine dinucleotide (NAD) is a key redox biomolecule responsible for cellular energy transduction to produce adenosine triphosphate (ATP). Based on this redox system, CNT yarn electrodes were fabricated by inserting a twist in CNT sheets with electrochemically deposited NAD and benzoquinone for redox shuttling. Consequently, the NAD/BQ/CNT yarn electrodes exhibited the maximum area capacitance (55.73 mF cm-2 ) under physiological conditions, such as phosphate-buffered saline and serum. In addition, the yarn electrodes showed a negligible loss of capacitance after 10 000 repeated charge/discharge cycles and deformation tests (bending/knotting). More importantly, NAD/BQ/CNT yarn electrodes implanted into the abdominal cavity of a rat's skin exhibited the stable in vivo electrical performance of a supercapacitor. Therefore, these findings demonstrate a redox biomolecule-applied platform for implantable energy storage devices.

Accelerometers are indispensable for detecting accelerating forces in automotive electronic systems. Although several accelerometers have been developed, they are still unstable for vehicle dynamics’ applications in the low-frequency range (0–20 Hz). Here, we report a novel type of accelerometer based on a coiled carbon nanotube (CNT) yarn as a self-powered and low-frequency range-covered acceleration sensor. The proposed sensor is designed in a compact fiber-like structure for practical applications. Open-circuit voltage (OCV) signals are consistently generated during the stretch-and-release process of the coiled CNT yarn by the applied sinusoidal accelerations, and the OCV changes increase linearly with increasing acceleration from 4.84 to 48.37 m/s2. Our accelerometer exhibits excellent dynamic sensing performance in the low-frequency range compared with commercial accelerometers. In an application as a CNT yarn device configured with a mass load, the OCV change is linearly proportional to the applied acceleration. When our accelerometer is attached to a seatbelt in a vehicle, it generates OCV changes from the movement of the body mass underlying a certain acceleration change. Given its excellent sensing performance, the CNT yarn acceleration sensor could further be developed for practical applications, such as seatbelts and car seats with fabric and textile.

Until recently, Nurr1 (NR4A2) was known as an orphan nuclear receptor without a canonical ligand-binding domain, featuring instead a narrow and tight cavity for small molecular ligands to bind. In-depth characterization of its ligand-binding pocket revealed that it is highly dynamic, with its structural conformation changing more than twice on the microsecond-to-millisecond timescale. This observation suggests the possibility that certain ligands are able to squeeze into this narrow space, inducing a conformational change to create an accessible cavity. The cocrystallographic structure of Nurr1 bound to endogenous ligands such as prostaglandin E1/A1 and 5,6-dihydroxyindole contributed to clarifying the crucial roles of Nurr1 and opening new avenues for therapeutic interventions for neurodegenerative and/or inflammatory diseases related to Nurr1. This review introduces novel endogenous and synthetic Nurr1 agonists and discusses their potential effects in Nurr1-related diseases., Neuropharmacology: a potential treatment strategy for dopamine-related brain disorders Compounds that activate a gene-regulating protein called Nurr1 could help treat Parkinson’s disease and other brain disorders related to abnormal dopamine signaling. A team led by Kwang-Soo Kim from Harvard Medical School, Belmont, USA, reviews the various compounds, both synthetic and natural, known to enhance the activity of Nurr1. This protein binds DNA to regulate the expression of target genes and was long thought not to have such triggering molecules or ligands, which have recently been identified by the team. These activating compounds seem to protect dopamine-producing neurons from cell injury in various Parkinson’s-related cell and animal models. Given Nurr1’s role in the development, differentiation, and survival of dopaminergic neurons in the midbrain, these compounds could help boost the capacity of malfunctioning dopaminergic neurons in patients with Parkinson’s disease, schizophrenia, bipolar disorder, and other neuropsychiatric conditions.

Crotamiton is an anti-scabies drug, but it was recently found that crotamiton also suppresses non-scabietic itching in mice. However, the underlying mechanism is largely unclear. Therefore, aim of the study is to investigate mechanisms of the anti-pruritic effect of crotamiton for non-scabietic itching. Histamine and chloroquine are used as non-scabietic pruritogens. The effect of crotamiton was identified using fluorometric intracellular calcium assays in HEK293T cells and primary cultured dorsal root ganglion (DRG) neurons. Further in vivo effect was evaluated by scratching behavior tests. Crotamiton strongly inhibited histamine-induced calcium influx in HEK293T cells, expressing both histamine receptor 1 (H1R) and transient receptor potential vanilloid 1 (TRPV1), as a model of histamine-induced itching. Similarly, it also blocked chloroquine-induced calcium influx in HEK293T cells, expressing both Mas-related G-protein-coupled receptor A3 (MRGPRA3) and transient receptor potential A1 (TRPA1), as a model of histamine-independent itching. Furthermore, crotamiton also suppressed both histamine- and chloroquine-induced calcium influx in primary cultures of mouse DRG. Additionally, crotamiton strongly suppressed histamine- and chloroquine-induced scratching in mice. Overall, it was found that crotamiton has an anti-pruritic effect against non-scabietic itching by histamine and chloroquine. Therefore, crotamiton may be used as a general anti-pruritic agent, irrespective of the presence of scabies.

A helical configuration confers a great advantage in artificial muscle due to great movement potential. However, most helical fibers are exposed to a high temperature to produce the coiled helical structure. Hence, thermoset polymer-composed hydrogels are difficult to fabricate as helical fibers due to their thermal degeneration. Here, we describe a self-helical hydrogel fiber that is produced without thermal exposure as a glucose-responsive artificial muscle. The sheath-core fiber was spontaneously transformed into the helical structure during the swelling state by balancing the forces between the untwisting force of the twisted nylon fiber core and the recovery force of the hydrogel sheath. To induce controllable actuation, we also applied a reversible interaction between phenylboronic acid and glucose to the self-helical hydrogel. Consequently, the maximum tensile stroke was 2.3%, and the performance was six times greater than that of the nonhelical fiber. The fiber also exhibited tensile stroke with load and a maximum work density of 130 kJ/m3. Furthermore, we showed a reversible tensile stroke in response to the change in glucose level. Therefore, these results indicate that the self-helical hydrogel fiber has a high potential for use in artificial muscles, glucose sensors, and drug delivery systems.

Flexible and stretchable fiber supercapacitors have been progressively improved for wearable electronic devices. However, they should be further improved with respect to stretchable range and stable electrochemical performance during dynamic movement when considering the tensile range for wearable applications. Here, we report a quasi-solid-state circular knitted MnO2@CNT supercapacitor with high tensile range. To fabricate this, CNT fibers were knitted into a circular shape using a knitting machine then subsequently electrochemically deposited by a pseudocapacitive material, MnO2. Consequently, the knitted MnO2@CNT fiber supercapacitors were structurally 100% stretchable, and their energy storage performance remained stable during knitted capacitor stretching of up to 100%. Maximum linear capacitance and area capacitance are considerably large (321.08 mF cm−1, 511.28 mF cm−2). In addition, the supercapacitor showed negligible loss of capacitance after 10 000 repeated charge/discharge cycles and dynamic stretching cycle testing. Furthermore, we also provided double-walled knitted MnO2@CNT supercapacitors by symmetrically inserting one knitted supercapacitor into another. The double-walled supercapacitor also exhibited a stable stretchability of up to 100% without loss of capacitance. Therefore, this highly stretchable fiber-type supercapacitor could be utilized for energy storage in wearable devices.

Anoctamin1 (ANO1) also known as TMEM16A is a transmembrane protein that functions as a Ca2+ activated chloride channel. Recently, the structure determination of a fungal Nectria haematococca TMEM16 (nhTMEM16) scramblase by X-ray crystallography and a mouse ANO1 by cryo-electron microscopy has provided the insight in molecular architecture underlying phospholipid scrambling and Ca2+ binding. Because the Ca2+ binding motif is embedded inside channel protein according to defined structure, it is still unclear how intracellular Ca2+ moves to its deep binding pocket effectively. Here we show that EF-hand like region containing multiple acidic amino acids at the N-terminus of ANO1 is a putative site regulating the activity of ANO1 by Ca2+ and voltage. The EF-hand like region of ANO1 is highly homologous to the canonical EF hand loop in calmodulin that contains acidic residues in key Ca2+-coordinating positions in the canonical EF hand. Indeed, deletion and Ala-substituted mutation of this region resulted in a significant reduction in the response to Ca2+ and changes in its key biophysical properties evoked by voltage pulses. Furthermore, only ANO1 and ANO2, and not the other TMEM16 isoforms, contain the EF-hand like region and are activated by Ca2+. Moreover, the molecular modeling analysis supports that EF-hand like region could play a key role during Ca2+ transfer. Therefore, these findings suggest that EF-hand like region in ANO1 coordinates with Ca2+ and modulate the activation by Ca2+ and voltage.

The electromagnetic pollution issues have been arising from the fast-growing development for electronic devices. Hence, the demand for materials with high electromagnetic interference (EMI) shielding performance has increased. Here, we developed self-healable, flexible and printable graphene oxide/silver nanowire films and textiles with excellent EMI shielding performance. The maximum electromagnetic interference shielding effectiveness (EMI SE) of 92 dB was recorded for an 18 μm-thickness film. In addition, the specific EMI shielding effectiveness was 31 dB cm3/g or 48,275 dB cm2/g when normalized to film thickness. Both values are higher than reported EMI shielding products. The composite film and coated textile were tolerant of damage induced by cracking or scratching. Damaging the films by cracking reduced the electrical conductivity, mechanical properties, and the EMI SE was decreased from 72 dB to 56 dB at 8.2 GHz. After the healing process, the EMI SE was recovered to 71 dB and mechanical properties restored. The EMI SE of textile reached a maximum of 30 dB which is suitable to use as a commercial EMI shielding product. In addition, the textile exhibited high flexibility, and showed excellent mechanical stability with no change in performance after 1000 bending cycles.

Significance Radial glial cells (RGCs), a type of neural stem cell in the developing brain, not only generate progenitors, newly born neurons and glial cells, but also deliver neurons through its process to the appropriate cortical target layers. Thus, the function of RGCs is crucial for cortex development, in which Cl− channels are thought to play a role. Here we highlight that Anoctamin 1 (ANO1)/TMEM16A, a Ca2+-activated Cl− channel, mediates the process extension in RGCs. ANO1-null mice show a decrease in cortical thickness with disorganized cortical layers. Thus, as a Cl− channel, ANO1 is involved in the process maturation of RGCs and contributes to cortex development., Neural stem cells (NSCs) are primary progenitor cells in the early developmental stage in the brain that initiate a diverse lineage of differentiated neurons and glia. Radial glial cells (RGCs), a type of neural stem cell in the ventricular zone, are essential for nurturing and delivering new immature neurons to the appropriate cortical target layers. Here we report that Anoctamin 1 (ANO1)/TMEM16A, a Ca2+-activated chloride channel, mediates the Ca2+-dependent process extension of RGCs. ANO1 is highly expressed and functionally active in RGCs of the mouse embryonic ventricular zone. Knockdown of ANO1 suppresses RGC process extension and protrusions, whereas ANO1 overexpression stimulates process extension. Among various trophic factors, brain-derived neurotrophic factor (BDNF) activates ANO1, which is required for BDNF-induced process extension in RGCs. More importantly, Ano1-deficient mice exhibited disrupted cortical layers and reduced cortical thickness. We thus conclude that the regulation of RGC process extension by ANO1 contributes to the normal formation of mouse embryonic brain.

The transdermal delivery system of nutrients, cosmetics, and drugs is particularly attractive for painless, noninvasive delivery and sustainable release. Recently, atmospheric pressure plasma techniques have been of great interest to improve the drug absorption rate in transdermal delivery. Currently, plasma-mediated changes in the lipid composition of the stratum corneum are considered a possible mechanism to increase transdermal permeability. Nevertheless, its molecular and cellular mechanisms in transdermal delivery have been largely confined and still veiled. Herein, we present the effects of cold plasma on transdermal transmission on porcine skin and the cellular permeability of keratinocytes and further demonstrate the production of nitric oxide from keratinocytes. Consequently, argon plasma irradiation for 60 s resulted in 2.5-fold higher transdermal absorption of aniline blue dye on porcine skin compared to the nontreated control. In addition, the plasma-treated keratinocytes showed an increased transmission of high-molecular-weight molecules (70 and 150 kDa) with the production of nitric oxide. Therefore, these findings suggest a promoting effect of low-temperature plasma on transdermal absorption, even for high-molecular-weight molecules. Moreover, plasma-induced nitric oxide from keratinocytes is likely to regulate transdermal permeability in the epidermal layer.

Biohybrid artificial muscle produced by integrating living muscle cells and their scaffolds with free movement in vivo is promising for advanced biomedical applications, including cell-based microrobotic systems and therapeutic drug delivery systems. Herein, we provide a biohybrid artificial muscle constructed by integrating living muscle cells and their scaffolds, inspired by bundled myofilaments in skeletal muscle. First, a bundled biohybrid artificial muscle was fabricated by the integration of skeletal muscle cells and hydrophilic polyurethane (HPU)/carbon nanotube (CNT) nanofibers into a fiber shape similar to that of natural skeletal muscle. The HPU/CNT nanofibers provided a stretchable basic backbone of the 3-dimensional fiber structure, which is similar to actin-myosin scaffolds. The incorporated skeletal muscle fibers contribute to the actuation of biohybrid artificial muscle. In fact, electrical field stimulation reversibly leads to the contraction of biohybrid artificial muscle. Therefore, the current development of cell-actuated artificial muscle provides great potential for energy delivery systems as actuators for implantable medibot movement and drug delivery systems. Moreover, the innervation of the biohybrid artificial muscle with motor neurons is of great interest for human-machine interfaces.

Bacterial vaginosis is a common female disease caused by a vaginal infection due to an overgrowth of bacteria that naturally live in the vaginal tract. Bacterial vaginosis has frequently been treated with the oral or vaginal administration of antibiotics and topical disinfectants. However, hygienic application of topical treatment deep in the vagina remains difficult. Herein, we introduce a novel vaginal cleaning device using plasma-activated water generated from supplied water. Remarkably, plasma source generation at atmospheric pressure is well known to eradicate bacterial infection through the generation of free radicals and/or chlorine chemicals with antimicrobial activity. The device was designed to alleviate a bacterial infection by spraying plasma-activated water generated from a cleaning solution container with plasma modules. The spray nozzle contains both a clean outlet and a suction outlet to spray and recover the plasma water, respectively, and is connected to a disposable silicone tube. The other nozzle, which has a laser light and air pump, can perform a second sterilization and dry the vagina after washing. Free chlorine chemicals with antibacterial activity were detected in the plasma-activated water by the device. Clinical application in patients with bacterial vaginosis confirmed the stability and effectiveness of our device. Therefore, these results show a novel clinical application of atmospheric pressure plasma to medical field as a plasma medicine.

Implantable devices have emerged as a promising industry. It is inevitable that these devices will require a power source to operate in vivo . Thus, to power implantable medical devices, biofuel cells (BFCs) that generate electricity using glucose without an external power supply have been considered. Although implantable BFCs have been developed for application in vivo , they are limited by their bulky electrodes and low power density. In the present study, we attempted to apply to living mice an implantable enzymatic BFC (EBFC) that was previously reported to be a high-power EBFC comprising carbon nanotube yarn electrodes. To improve their mechanical properties and for convenient implantation, the electrodes were coated with Nafion and twisted into a micro-sized, two-ply, one-body system. When the two-ply EBFC system was implanted in the abdominal cavity of mice, it provided a high-power density of 0.3 mW/cm2. The two-ply EBFC system was injected through a needle using a syringe without surgery and the inflammatory response in vivo initially induced by the injection of the EBFC system was attenuated after 7 days, indicating the biocompatibility of the system in vivo .

Burn-related injuries are devastating injuries with a high mortality rate that affect people of all ages worldwide. We assessed the effectiveness of plasma jet treatment in altering the expression of genes involved in wound healing in a prospective longitudinal observational animal study. Six male Sprague–Dawley rats weighing 350 g were used, and burn wounds were made by applying a preheated brass comb (100°C) to the back of the rats, resulting in four full-thickness burn wounds separated by three interspaces. A total of 18 burn wounds were induced on three rats. One side of the burn, on each rat received plasma treatment (plasma group), while the other side did not (control group). The interspaces were subjected to the plasma jet for 2 minutes per day until 7 days post-wounding. Plasma treatment significantly decreased the expression of proinflammatory cytokines. Furthermore, an increase in the expression of anti-inflammatory cytokines was observed in the plasma group. We showed that plasma jet treatment could improve burn wound healing by altering the expression of genes involved in the development of wound healing.

Flexible and stretchable fiber supercapacitors have been progressively improved for wearable electronic devices. However, they should be further improved with respect to stretchable range and stable electrochemical performance during dynamic movement when considering the tensile range for wearable applications. Here, we report a quasi-solid-state circular knitted MnO

The orphan nuclear receptor Nurr1 is critical for the development, maintenance and protection of midbrain dopaminergic (mDA) neurons. Here we show that prostaglandin E1 (PGE1) and its dehydrated metabolite, PGA1, directly interact with the ligand-binding domain (LBD) of Nurr1 and stimulate its transcriptional function. We also report the crystallographic structure of Nurr1-LBD bound to PGA1 at 2.05 Å resolution. PGA1 couples covalently to Nurr1-LBD by forming a Michael adduct with Cys566, and induces notable conformational changes, including a 21° shift of the activation function-2 helix (H12) away from the protein core. Furthermore, PGE1/PGA1 exhibit neuroprotective effects in a Nurr1-dependent manner, prominently enhance expression of Nurr1 target genes in mDA neurons and improve motor deficits in 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine-lesioned mouse models of Parkinson's disease. Based on these results, we propose that PGE1/PGA1 represent native ligands of Nurr1 and can exert neuroprotective effects on mDA neurons, via activation of Nurr1's transcriptional function. Ministry of Education (MOE) National Medical Research Council (NMRC) National Research Foundation (NRF) This work was supported by NIH grant nos. NS070577 and NS084869 (to K.-S.K.), NRF-2018M3A9B5023055 grant (to C.-H.K.), Ministry of Education Singapore AcRF Tier 2 Grant (no. ARC55/16) and Tang Tieng See Advancement Fund (to H.S.Y.), and National Medical Research Council, Singapore (grant no. TCR/013-NNI/2014; to K.L.L. and H.S.Y.).

TRPM2 a cation channel is also known to work as an enzyme that hydrolyzes highly reactive, neurotoxic ADP-ribose (ADPR). Although ADPR is hydrolyzed by NUT9 pyrophosphatase in major organs, the enzyme is defective in the brain. The present study questions the role of TRPM2 in the catabolism of ADPR in the brain. Genetic ablation of Trpm2 results in the disruption of ADPR catabolism that leads to the accumulation of ADPR and reduction in AMP. Trpm2−/− mice elicit the reduction in autophagosome formation in the hippocampus. Trpm2−/− mice also show aggregations of proteins in the hippocampus, aberrant structural changes and neuronal connections in synapses, and neuronal degeneration. Trpm2−/− mice exhibit learning and memory impairment, enhanced neuronal intrinsic excitability, and imbalanced synaptic transmission. These results respond to long-unanswered questions regarding the potential role of the enzymatic function of TRPM2 in the brain, whose dysfunction evokes protein aggregation. In addition, the present finding answers to the conflicting reports such as neuroprotective or neurodegenerative phenotypes observed in Trpm2−/− mice. Electronic supplementary material The online version of this article (10.1007/s12035-018-1309-0) contains supplementary material, which is available to authorized users.

Anoctamin 1 (ANO1) is an anion channel that is activated by changes in cytosolic Ca2＋ concentration and noxious heat. Although the critical roles of ANO1 have been elucidated in various cell types, the control of its gating mechanisms by Ca2＋ and heat remain more elusive. To investigate critical amino acid residues for modulation of Ca2＋ and heat sensing, we constructed a randomized mutant library for ANO1. Among 695 random mutants, reduced Ca2＋ sensitivity was observed in two mutants (mutant 84 and 87). Consequently, the E143A mutant showed reduced sensitivity to Ca2＋ but not to high temperatures, whereas the E705V mutant exhibited reduced sensitivity to both Ca2＋ and noxious heat. These results suggest that the glutamic acids (E) at 143 and 705 residues in ANO1 are critical for modulation of Ca2＋ and/or heat responses. Furthermore, these findings help to provide a better understanding of the Ca2＋-mediated activation and heat-sensing mechanism of ANO1. [BMB Reports 2018; 51(5): 236-241].

Itch is an unpleasant sensation that evokes behavioral responses such as scratching the skin. Interestingly, it is conceived that the perception of itch sensation is influenced by age. Indeed, accumulating evidence supports the idea that even children or younger adults show distinctive itch sensation depending on age. This evidence implies the presence of a mechanism that regulates the perception of itch sensation in an age-dependent fashion. Therefore, the purpose of the present study was to investigate a putative mechanism for the age-dependent perception of itch sensation by comparing histamine-induced scratching behaviors in 45-day old (D45) and 75-day old male "young adult" mice. The results indicated that, following histamine administration, the D75 mice spent a longer time scratching than D45 mice. However, the intensity of the calcium influx induced by histamine in primary culture of dorsal root ganglia (DRG) neurons was not different between D45 and D75 mice. Moreover, no apparent difference was observed in mRNA levels of a characteristic His-related receptor and ion channel. In contrast, the mRNA levels of Toll-Like Receptor 4 (TLR4) were increased approximately by two-fold in D75 DRG compared with D45 DRG. Additionally, D75-derived DRG neurons exhibited enhanced intracellular calcium increase by lipopolysaccharide (LPS, a TLR4 agonist) than those of D45 mice. Furthermore, intensities of calcium influx induced by histamine were significantly potentiated when co-treated with LPS in D75 DRG neurons, but not in those of D45 mice. Thus, it appears that D75 mice showed enhanced histamine-induced scratching behaviors not by increased expression levels of histamine-related genes, but probably due to augmented TLR4 expression in DRG neurons. Consequently, the current study found that different perception levels of histamine-induced itch sensation are present in different age groups of young adult mice.

Pain is a protective mechanism that enables us to avoid potentially harmful environments. However, when pathologically persisted and aggravated under severely injured or inflamed conditions, pain often reduces the quality of life and thus is considered as a disease to eliminate. Inflammatory and/or neuropathic mechanisms may exaggerate interactions between damaged tissues and neural pathways for pain mediation. Similar mechanisms also promote the communication among cellular participants in synapses at spinal or higher levels, which may amplify nociceptive firing and subsequent signal transmission, deteriorating the pain sensation. In this pathology, important cellular players are afferent sensory neurons, peripheral immune cells, and spinal glial cells. Arising from damage of injury, overloaded interstitial and intracellular reactive oxygen species (ROS) and intracellular Ca2+ are key messengers in the development and maintenance of pathologic pain. Thus, an ROS-sensitive and Ca2+-permeable ion channel that is highly expressed in the participant cells might play a critical role in the pathogenesis. Transient receptor potential melastatin subtype 2 (TRPM2) is the unique molecule that satisfies all of the requirements: the sensitivity, permeability, and its expressing cells. Notable progress in delineating the role of TRPM2 in pain has been achieved during the past decade. In the present review, we summarize the important findings in the key cellular components that are involved in pathologic pain. This overview will help to understand TRPM2-mediated pain mechanisms and speculate therapeutic strategies by utilizing this updated information.

Harmful maternal behaviors, such as drinking and smoking, negatively affect embryonic development. In contrast, regular maternal exercise is believed to be beneficial to the fetus. Although it is not surprising that voluntary physical activities are advantageous to fetal development, it remains unclear whether involuntary maternal exercise has similar effects. The constituents of the amniotic fluid (AF) inevitably reflect the maternal plasma. Therefore, it is speculated that exercise-induced changes in maternal plasma can influence fetal development through changes in AF composition. Therefore, we investigated the effect of AF on fetal neurodevelopment and changes in AF composition after involuntary swimming exercise (SE) in an animal model. We found that there was a severe reduction in the number of embryos implanted in the uterus of SE rats. Surprisingly, cortisol level (an inducible stress hormone) was significantly increased in AF from SE rats. In contrast, the growth factors NGF and VEGF were reduced in the AF from SE rats. In the cultured embryonic cortical neurons, the treatment of control (CTL) rat-derived AF significantly increased the phosphorylation of extracellular signal-regulated kinase 1/2 (ERK1/2)-mediated signaling that is essential for fetal neurodevelopment. However, the AF extracted from SE rats reversely suppressed the phosphorylation of ERK1/2-mediated signaling in cortical neurons compared to that in CTL rats. Indeed, the co-treatment with control AF and dexamethasone, a synthetic glucocorticoid, inhibited the phosphorylation of ERK1/2 in a dose-dependent manner. This finding suggests that the inhibition of ERK1/2 can be attributed to increased cortisol level in AF resulting from involuntary exercise. Therefore, involuntary maternal swimming increases cortisol level in AF, which ultimately hinders the ERK1/2 signaling pathway in embryonic neurons. These findings also suggest that involuntary maternal exercise can have undesirable effects on fetal neurodevelopment, which is potentially mediated by elevated AF cortisol level.

A self-healing electrode is an electrical conductor that can repair internal damage by itself, similar to human skin. Since self-healing electrodes are based on polymers and hydrogels, these components are still limited by low electrical conductivity and mechanical strength. In this study, we designed an electrically conductive, mechanically strong, and printable self-healing electrode using liquid crystal graphene oxide (LCGO) and silver nanowires (AgNWs). The conductive ink was easily prepared by simply mixing LCGO and AgNWs solutions. The ultrathin (3 μm thick) electrode can be printed in various shapes, such as a butterfly, in a freestanding state. The maximum conductivity and strength of the LCGO/AgNW composite were 17 800 S/cm and 4.2 MPa, respectively; these values are 24 and 4 times higher, respectively, than those of a previously developed self-healing electrode. The LCGO/AgNW composite self-healed internal damage in ambient conditions with moisture and consequently recovered 96.8% electrical conductivity and 95% mechanical toughness compared with the undamaged state. The electrical properties of the composite exhibited metallic tendencies. Therefore, these results suggest that the composite can be used as an artificial electronic skin that detects environmental conditions, such as compression and temperature. This self-healing artificial electronic skin could be applied to human condition monitoring and robotic sensing systems.

For over a half-century the anti-malarial drug chloroquine (CQ) has been used as a therapeutic agent, alone or in combination, to treat autoimmune diseases. However, neither the underlying mechanism(s) of action nor their molecular target(s) are well defined. The orphan nuclear receptor Nurr1 (also known as NR4A2) is an essential transcription factor affecting the development and maintenance of midbrain dopaminergic neurons. In this study, using in vitro T cell differentiation models, we demonstrate that CQ activates TREG cell differentiation and induces Foxp3 gene expression in a Nurr1-dependent manner. Remarkably, CQ appears to induce Nurr1 function by two distinct mechanisms: firstly, by direct binding to Nurr1’s ligand-binding domain and promoting its transcriptional activity and secondly by upregulation of Nurr1 expression through the CREB signaling pathway. In contrast, CQ suppressed gene expression and differentiation of pathogenic TH17 cells. Importantly, using a valid animal model of inflammatory bowel disease (IBD), we demonstrated that CQ promotes Foxp3 expression and differentiation of TREG cells in a Nurr1-dependent manner, leading to significant improvement of IBD-related symptoms. Taken together, these data suggest that CQ ameliorates autoimmune diseases via regulating Nurr1 function/expression and that Nurr1 is a promising target for developing effective therapeutics of human inflammatory autoimmune diseases.

Spider silks represent stretchable and contractible fibers with high toughness. Those tough fibers with stretchability and contractibility are attractive as energy absorption materials, and they are needed for wearable applications, artificial muscles, and soft robotics. Although carbon-based materials and poly(vinyl alcohol) (PVA) composite fibers exhibit high toughness, they are still limited in low extensibility and an inability to operate in the wet-state condition. Herein, we report stretchable and contractible fiber with toughness that is inspired by the structure of spider silk. The bioinspired tough fiber provides 495 J/g of gravimetric toughness, which exceeds 165 J/g of spider silk. Besides, the tough fiber was reversibly stretched to ∼80% strain without damage. This toughness and stretchability are realized by hybridization of aligned graphene oxide/multiwalled carbon nanotubes in a polyurethane matrix as elastic amorphous regions and β-sheet segments of spider silk. Interestingly, the bioinspired tough fiber contracted up to 60% in response to water and humidity similar to supercontraction of the spider silk. It exhibited 610 kJ/m3 of contractile energy density, which is higher than previously reported moisture driven actuators. Therefore, this stretchable and contractible tough fiber could be utilized as an artificial muscle in soft robotics and wearable devices.

Controllable and miniaturised mechanical actuation is one of the main challenges facing various emerging technologies, such as soft robotics, drug delivery systems, and microfluidics. Here we introduce a simple method for constructing actuating devices with programmable complex motions. Thermally responsive hydrogels based on poly(N-isopropylacrylamide) (PNIPAM) and its functionalized derivatives (f-PNIPAM) were used to control the lower critical solution temperature (LCST) or the temperature at which the gel volume changes. Techniques for ultra-violet crosslinking the monomer solutions were developed to generate gel sheets with controllable crosslink density gradients that allowed bending actuation to specified curvatures by heating through the LCST. Simple molding processes were then used to construct multi-transform devices with complex shape changes, including a bioinspired artificial flower that shows blossoming and reverse blossoming with a change in temperature.

Smart systems are those that display autonomous or collaborative functionalities, and include the ability to sense multiple inputs, to respond with appropriate operations, and to control a given situation. In certain circumstances, it is also of great interest to retain flexible, stretchable, portable, wearable, and/or implantable attributes in smart electronic systems. Among the promising candidate smart materials, carbon nanotubes (CNTs) exhibit excellent electrical and mechanical properties, and structurally fabricated CNT-based fibers and yarns with coil and twist further introduce flexible and stretchable properties. A number of notable studies have demonstrated various functions of CNT yarns, including sensors, actuators, and energy storage. In particular, CNT yarns can operate as flexible electronic sensors and electrodes to monitor strain, temperature, ionic concentration, and the concentration of target biomolecules. Moreover, a twisted CNT yarn enables strong torsional actuation, and coiled CNT yarns generate large tensile strokes as an artificial muscle. Furthermore, the reversible actuation of CNT yarns can be used as an energy harvester and, when combined with a CNT supercapacitor, has promoted the next-generation of energy storage systems. Here, progressive advances of CNT yarns in electrical sensing, actuation, and energy storage are reported, and the future challenges in smart electronic systems considered.

The strong peristaltic contraction of the stomach facilitates mixing and emptying of ingested food, which occurs rhythmically at approximately 3 cycles/min (cpm) in humans. Generally, most patients with gastroparesis show gastric electrical dysrhythmia that is disrupted electrical signals controlling gastric contractions. For treatment of gastric electrical dysrhythmia, in vivo electrical impulses to the stomach via an implanted gastric stimulator have been known to restore these gastric deformations. Nevertheless, improved sensors to monitor gastric contractions are still needed in current gastric stimulators. Recently, we have developed a new technology converting mechanical motion to electrical energy by using stretch-induced capacitance changes of a coiled carbon-nanotube (CNT) yarn. For its potential use as a gastric deformation sensor, the performance of a coiled CNT yarn was evaluated in several biological fluids. For a sinusoidal stretch to 30%, the peak-to-peak open-circuit voltage (OCV) was consistently generated at frequencies below 0.1 Hz. This sinusoidal variation in OCV augmented as the strain increased from 10 to 30%. In an in vitro artificial gastric system, the OCV was approximately linearly proportional to the balloon volume, which can monitor periodic deformations of the balloon at 2, 3, and 4 cpm as shown for human gastric deformations. Moreover, stretchy coiled yarns generate the peak electrical voltage and power when deformed. The present study shows that a self-powered CNT yarn sensor can not only monitor the changes in frequency and amplitude of volumetric change but also generate electrical power by periodic deformations of the balloon. Therefore, it seems possible to automatically deliver accurate electrical impulses according to real-time evaluation of a patient's gastric deformation based on information on the frequency, amplitude, and rate of the OCV from CNT yarn.

Although guest-filled carbon nanotube yarns provide record performance as torsional and tensile artificial muscles, they are expensive, and only part of the muscle effectively contributes to actuation. We describe a muscle type that provides higher performance, in which the guest that drives actuation is a sheath on a twisted or coiled core that can be an inexpensive yarn. This change from guest-filled to sheath-run artificial muscles increases the maximum work capacity by factors of 1.70 to 2.15 for tensile muscles driven electrothermally or by vapor absorption. A sheath-run electrochemical muscle generates 1.98 watts per gram of average contractile power-40 times that for human muscle and 9.0 times that of the highest power alternative electrochemical muscle. Theory predicts the observed performance advantages of sheath-run muscles.

Underwater robots and vehicles have received great attention due to their potential applications in remote sensing and search and rescue. A challenge for micro aquatic robots is the lack of small motors needed for three-dimensional locomotion in water. Here, we show a simple diving and surfacing device fabricated from thermo-sensitive poly(N-isopropylacrylamide) or a poly(N-isopropylacrylamide)-containing hydrogel. The poly(N-isopropylacrylamide)-containing device exhibited fast and reversible diving/surfacing cycles in response to changing temperature. Modulation of the interaction between poly(N-isopropylacrylamide) chains and water molecules at temperatures above or below the lower critical solution temperature regulates the gel density through the swelling and de-swelling. The gel surfaced in water when heated and sank when cooled. We further showed reversible diving/surfacing cycles of the device when exposed to electrical and ultrasonic stimuli. Finally, a small electrically heated gel was incorporated into a miniature submarine and used to control the diving depth. These results suggest that the poly(N-isopropylacrylamide)-containing device has good potential for underwater remote-controlled micro aquatic robots.