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Breast cancer is one of the leading causes of death among women globally, making its diagnosis and treatment challenging. The use of nanotechnology for cancer diagnosis and treatment is an emerging area of research. To address this issue, multiwalled carbon nanotubes (MWCNTs) were ligand exchanged with butyric acid (BA) to gain hydrophilic character. The successful functionalization was confirmed by FTIR spectroscopy. Surface morphology changes were observed using SEM, while TEM confirmed the structural integrity of the MWCNTs after functionalization. Particle size, zeta potential, and UV spectroscopy were also performed to further characterize the nanoparticles. The breast cancer aptamer specific to Mucin-1 (MUC-1) was then conjugated with the functionalized MWCNTs. These MWCNTs successfully targeted breast cancer cells (MDA-MB-231) as examined by cellular uptake studies and exhibited a reduction in cancer-induced inflammation, as evidenced by gene transcription (qPCR) and protein expression (immunoblotting) levels. Immunoblot and confocal-based immunofluorescence assay (IFA) indicated the ability of CNTs to induce photothermal cell death of MDA-MB-231 cells. Upon imaging, cancer cells were effectively visualized due to the MWCNTs' ability to act as magnetic resonance imaging (MRI) contrast agents. Additionally, MWCNTs demonstrated photothermal capabilities to eliminate bound cancer cells. Collectively, our findings pave the way for developing aptamer-labeled MWCNTs as viable "theranostic alternatives" for breast cancer treatment., (© 2024. The Author(s).)

In patients with high-level radiation exposure, gastrointestinal injury is the main cause of death. Despite the severity of damage to the gastrointestinal tract, no specific therapeutic option is available. Tauroursodeoxycholic acid (TUDCA) is a conjugated form of ursodeoxycholic acid that suppresses endoplasmic reticulum (ER) stress and regulates various cell-signaling pathways. We investigated the effect of TUDCA premedication in alleviating intestinal damage and enhancing the survival of C57BL/6 mice administered a lethal dose (15Gy) of focal abdominal irradiation. TUDCA was administered to mice 1 h before radiation exposure, and reduced apoptosis of the jejunal crypts 12 h after irradiation. At later timepoint (3.5 days), irradiated mice manifested intestinal morphological changes that were detected via histological examination. TUDCA decreased the inflammatory cytokine levels and attenuated the decrease in serum citrulline levels after radiation exposure. Although radiation induced ER stress, TUDCA pretreatment decreased ER stress in the irradiated intestinal cells. The effect of TUDCA indicates the possibility of radiation therapy for cancer in tumor cells. TUDCA did not affect cell proliferation and apoptosis in the intestinal epithelium. TUDCA decreased the invasive ability of the CT26 metastatic colon cancer cell line. Reduced invasion after TUDCA treatment was associated with decreased matrix metalloproteinase (MMP)-7 and MMP-13 expression, which play important roles in invasion and metastasis. This study shows a potential role of TUDCA in protecting against radiation-induced intestinal damage and inhibiting tumor cell migration without any radiation and radiation therapy effect., Competing Interests: Declaration of competing interest The authors declare the following financial interests/personal relationships which may be considered as potential competing interests: Joong Sun Kim reports financial support was provided by National Research Foundation of Korea. If there are other authors, they declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier Inc. All rights reserved.)

Self-assembly of designed molecules has enabled the construction of a variety of functional nanostructures. Specifically, adaptable self-assembly has demonstrated several advantageous features for smart materials. Here, we demonstrate that an α-helical coiled coil conjugated with a dendrimer can adapt to spatial restriction due to the strong steric repulsion between dendrimer chains. The adaptable transformation of a tetrameric coiled coil to a trimeric coiled coil can be confirmed using analytical ultracentrifugation upon conjugation of the dendrimer to the coiled coil-forming building block. Interestingly, circular dichroism spectroscopy analysis of the dendrimer conjugate revealed an unconventional trend: the multimerization of the coiled coil is inversely dependent on concentration. This result implies that the spatial crowding between the bulky dendritic chains is significantly stronger than that between linear chains, thereby affecting the overall assembly process. We further illustrated the application potential by decorating the surface of gold nanorods (AuNRs) with the adaptable coiled coil. The dendrimer-coiled coil peptide conjugate can be utilized to fabricate organic-inorganic nanohybrids with enhanced colloidal and thermal stabilities. This study demonstrates that the coiled coil can engage in the adaptable mode of self-assembly with the potential to form dynamic peptide-based materials., (© 2024 Wiley-VCH GmbH.)

This study utilized arterial spin labeling-magnetic resonance imaging (ASL-MRI) to explore the developmental trajectory of brain activity associated with attention deficit hyperactivity disorder (ADHD). Pulsed arterial spin labeling (ASL) data were acquired from 157 children with ADHD and 109 children in a control group, all aged 6-12 years old. Participants were categorized into the age groups of 6-7, 8-9, and 10-12, after which comparisons were performed between each age group for ASL analysis of cerebral blood flow (CBF). In total, the ADHD group exhibited significantly lower CBF in the left superior temporal gyrus and right middle frontal gyrus regions than the control group. Further analysis revealed: (1) The comparison between the ADHD group (N = 70) aged 6-7 and the age-matched control group (N = 33) showed no statistically significant difference between. (2) However, compared with the control group aged 8-9 (N = 39), the ADHD group of the same age (N = 53) showed significantly lower CBF in the left postcentral gyrus and left middle frontal gyrus regions. (3) Further, the ADHD group aged 10-12 (N = 34) demonstrated significantly lower CBF in the left superior occipital region than the age-matched control group (N = 37). These age-specific differences suggest variations in ADHD-related domains during brain development post age 6-7., (© 2024. The Author(s).)

Objective: : To examine the effect of mobile neurofeedback training on the clinical symptoms, attention abilities, and execution functions of children with attention deficit hyperactivity disorder (ADHD)., Methods: : The participants were 74 children with ADHD aged 8-15 years who visited the Department of Child and Adolescent Psychiatry at Seoul National University Children's Hospital. The participants were randomly assigned to the mobile neurofeedback (n = 35) or control (sham; n = 39) group. Neurofeedback training was administered using a mobile app (equipped with a headset with a 2-channel electroencephalogram [EEG] sensor) for 30 min/day, 3 days/week, for 3 months. Children with ADHD were individually administered various neuropsychological tests, including the continuous performance test, Children's Color Trails Test-1 and 2, and Stroop Color and Word Tests. The effects of mobile neurofeedback were evaluated at baseline and at 3 and 6 months after treatment initiation., Results: : Following treatment, both mobile neurofeedback-only and sham-only groups showed significant improvements in attention and response inhibition. In the visual continuous performance test, omission errors decreased to the normal range in the mobile neurofeedback-only group after training, suggesting that mobile neurofeedback effectively reduced inattention in children with ADHD. In the advanced test of attention, auditory response times decreased in the mobile neurofeedback + medication group after training, but increased in the sham+medication group. Overall, there were no significant between-group differences in other performance outcomes., Conclusion: : Mobile neurofeedback may have potential as an additional therapeutic option alongside medication for children with ADHD.

Although peptides notoriously have poor intrinsic pharmacokinetic properties, it is well-known that nanostructures with excellent pharmacokinetic properties can be designed. Noticing that peptide inhibitors are generally nonpolar, here, we consolidate the peptide inhibitor targeting intracellular protein-protein interactions (PPIs) as an integral part of biodegradable self-assembled depsipeptide nanostructures (SdPNs). Because the peptide inhibitor has the dual role of PPI inhibition and self-assembly in this design, problems associated with the poor pharmacokinetics of peptides and encapsulation/entrapment processes can be overcome. Optimized SdPNs displayed better tumor targeting and PPI inhibition properties than the comparable small molecule inhibitor in vivo. Kinetics of PPI inhibition for SdPNs were gradual and controllable in contrast to the rapid inhibition kinetics of the small molecule. Because SdPN is modular, any appropriate peptide inhibitor can be incorporated into the platform without concern for the poor pharmacokinetic properties of the peptide., Competing Interests: Declaration of Competing Interest Y.B.L. and H.H.S. have filed a patent for the development of the SdPN platform. The authors declare the following financial interests/personal relationships which may be considered as potential competing interests: Yong-beom Lim has patent pending to Yonsei University. Hyun-seok Hwang has patent pending to Yonsei University., (Copyright © 2023 Elsevier B.V. All rights reserved.)

The quaternary structure of proteins extends the functionality of monomeric proteins. Similarly, self-assembled protein nanostructures (SPrNs) have great potential to improve the functionality and complexity of proteins; however, the difficulty associated with the fabrication of SPrNs is far greater than that associated with the fabrication of self-assembled peptides or polymers and often requires sophisticated computational design. To make the process of SPrN formation simpler and more intuitive, herein, we devise a strategy to adopt an irreversible self-assembled peptide nanostructure (SPeN) process en route to the formation of SPrNs. The strategy employs three sequential steps: first, the formation of SPeNs (an equilibrium process); second, covalent capture of SPeNs (an irreversible process); third, the final assembly of SPrNs via protein-peptide interactions (an equilibrium process). This strategy allowed us to fabricate SPrNs in which the size of the protein was approximately 9 times higher than that of the self-assembling peptide. Furthermore, we demonstrated that the irreversible SPeN could be used as a primary building block for assembly into superstructures. Overall, this strategy is conceptually as simple as SPeN fabrication and is potentially applicable to any soluble protein.

Objective: : Attention deficit hyperactivity disorder (ADHD) is a common neurodevelopmental disorder in children and adults characterized by cognitive and emotional self-control deficiencies. Previous functional near-infrared spectroscopy (fNIRS) studies found significant group differences between ADHD children and healthy controls during cognitive flexibility tasks in several brain regions. This study aims to apply a machine learning approach to identify medication-naive ADHD patients and healthy control (HC) groups using task-based fNIRS data., Methods: : fNIRS signals from 33 ADHD children and 39 HC during the Stroop task were analyzed. In addition, regularized linear discriminant analysis (RLDA) was used to identify ADHD individuals from healthy controls, and classification performance was evaluated., Results: : We found that participants can be correctly classified in RLDA leave-one-out cross validation, with a sensitivity of 0.67, specificity of 0.93, and accuracy of 0.82., Conclusion: : RLDA using only fNIRS data can effectively discriminate children with ADHD from HC. This study suggests the potential utility of the fNIRS signal as a diagnostic biomarker for ADHD children.

Introduction: Since the Coronavirus disease 2019 (COVID-19), public safety measures, including social distancing and school closures, have been implemented, precipitating psychological difficulties and heightened online activities for adolescents. However, studies examining the impact of the pandemic on adolescent mental health and their coping strategies in Asian countries are limited. Further, most studies have used survey measures to capture mental health challenges so far. Accordingly, this study aimed to examine the psychological challenges South Korean adolescents experienced and their coping strategies during the pandemic using the Natural Language Processing (NLP) and Text mining (TM) technique on adolescents' social media texts/posts., Methods: The data were gathered from social media texts/posts such as online communities, Twitter, and personal blogs from January 1, 2019, to October 31, 2021. The 12,520,250 texts containing keywords related to adolescents' common psychological difficulties reported during the pandemic, including self-harm, Attention-Deficit/Hyperactivity Disorders (ADHD), and insomnia, were analyzed by TM, NLP using information extraction, co-occurrence and sentiment analysis. The monthly frequency of the keywords and their associated words was also analyzed to understand the time trend., Results: Adolescents used the word "self-harm" in their social media texts more frequently during the second wave of COVID-19 (August to September 2020). "Friends" was the most associated word with "self-harm." While the frequency of texts with "Insomnia" stayed constant throughout the pandemic, the word "ADHD" was increasingly mentioned in social media. ADHD and insomnia were most frequently associated with ADHD medications and sleeping pills, respectively. Friends were generally associated with positive words, while parents were associated with negative words., Conclusion: During COVID-19, Korean adolescents often expressed their psychological challenges on social media platforms. However, their coping strategies seemed less efficient to help with their difficulties, warranting strategies to support them in the prolonged pandemic era. For example, Korean adolescents shared psychological challenges such as self-harm with friends rather than their parents. They considered using medicine (e.g., sleeping pills and ADHD medication) as coping strategies for sleep and attention problems., Competing Interests: J-MK was employed by VAIV company. The remaining authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2023 Do, Kim, Lim, Kim, Kwon, Kim, Lee and Kim.)

Although mRNA delivery technology is very promising, problems in safety and transport arise due to the intrinsically low thermodynamic stability of the current mRNA carriers. Considering that mRNAs are filamentous and a nanotube is one of the most thermodynamically stable shapes among nanoassemblies, a nanotube is one of the most stable supramolecular structures that can be assembled with mRNA. Here, we develop a nanotube-shaped filamentous mRNA delivery platform that shows exceptionally high thermodynamic stability. The key to the development of the mRNA nanotube is the design of self-adjusting supramolecular building blocks (SABs) that have two disparate properties, i.e., dynamic property and stiffness, in a single molecule. The counterbalance of the dynamic property and stiffness in SABs enables the coating of mRNA by winding its way through the flexible and irregular mRNA chain via cooperative interactions. SAB nanotubes with targeting ligands installed show a high uptake efficiency in mammalian cells and controllable gene expression behavior. Thus, the mRNA nanotube provides an enabling technology toward the development of safe and stable mRNA vaccines and therapeutics.

This study presents the development of a β-hairpin (tryptophan zipper, Trpzip)-based molecular tweezer (MT) that can control the folding and binding of α-helical peptides. When an α-helix isolated from the p53 protein was conjugated with Trpzip in an optimized macrocyclic structure, the folded β-hairpin stabilized the helix conformation through the side chain-to-side chain stapling strategy, which notably enhanced target (hDM2) affinity of the peptide. On the other hand, the helicity and binding affinity were significantly reduced when the hairpin was unfolded by a redox stimulus. This stimulus-responsive property was translated into the effective capture and release of model multivalent biomaterials, hDM2-gold nanoparticle conjugates. Since numerous protein interactions are mediated by α-helical peptides, these results suggest that the β-hairpin-based MT holds great potential to be utilized in various biomedical applications, such as protein interaction inhibition and cancer biomarker ( e.g. , circulating tumor cells and exosomes) detection., Competing Interests: There are no conflicts to declare., (This journal is © The Royal Society of Chemistry.)

Because organic molecules and materials are generally insensitive or weakly sensitive to magnetic fields, a certain means to enhance their magnetic responsiveness needs to be exploited. Here we show a strategy to amplify the magnetic responsiveness of self-assembled peptide nanostructures by synergistically combining the concepts of perfect α-helix and rod-coil supramolecular building blocks. Firstly, we develop a monomeric, nonpolar, and perfect α-helix (MNP-helix). Then, we employ the MNP-helix as the rod block of rod-coil amphiphiles (rod-coils) because rod-coils are well-suited for fabricating responsive assemblies. We show that the self-assembly processes of the designed rod-coils and disassembly of rod-coil/DNA complexes can be controlled in a magnetically responsive manner using the relatively weak magnetic field provided by the ordinary neodymium magnet [0.07 ~ 0.25 Tesla (T)]. These results demonstrate that magnetically responsive organic assemblies usable under practical conditions can be realized by using rod-coil supramolecular building blocks containing constructively organized diamagnetic moieties., (© 2023. The Author(s).)

Objectives: Tic disorders are highly heritable; however, growing evidence suggests that environmental factors play a significant role in their pathogenesis. Studies on these factors have been inconsistent, with conflicting results. Therefore, this study aimed to examine the associations of pre- and perinatal exposure to Tourette syndrome (TS) or chronic tic disorders (CTD) in Korean school-aged children., Methods: This case-control study used data from a large prospective cohort study. The primary outcome was TS/CTD diagnosis according to the Diagnostic and Statistical Manual of Mental Disorders, 5th edition (DSM-5) criteria and Kiddie-Schedule for Affective Disorders and Schizophrenia-Present and Lifetime Version-Korean Version. Demographic, pre-, and perinatal information was obtained from the maternal questionnaires. Data between the TS/CTD and control groups were compared using the chi-squared or Student's t-test, as appropriate. Two-step logistic regression analyses were used to test the association between TS/CTD and pre- and perinatal risk factors., Results: We included of 223 children (78 with TS/CTD and 145 controls). Significant differences in the demographic data between the two groups were observed. The male sex ratio, mean parental age, parental final education level, and family history of tics were included as confounders. In the final adjusted multivariable model, TS/CTD was significantly associated with antiemetic exposure during pregnancy (odds ratio [OR]=16.61, 95% confidence interval [CI] 1.49-185.22, p=0.02) and medically assisted reproduction (OR=7.89, 95% CI 2.28-27.28, p=0.01)., Conclusion: Antiemetic exposure and medically assisted reproduction are significantly associated with the risk of TS/CTD. These results should be replicated in future prospective and gene-by-environment studies., Competing Interests: Conflicts of Interest The authors have no potential conflicts of interest to disclose., (Copyright © 2023 Korean Academy of Child and Adolescent Psychiatry.)

Antimicrobial peptides (AMPs) attracted attention as potential source of novel antimicrobials. Multi-drug resistant (MDR) infections have emerged as a global threat to public health in recent years. Furthermore, due to rapid emergence of new diseases, there is pressing need for development of efficient antimicrobials. AMPs are essential part of the innate immunity in most living organisms, acting as the primary line of defense against foreign invasions. AMPs kill a wide range of microorganisms by primarily targeting cell membranes or intracellular components through a variety of ways. AMPs can be broadly categorized based on their physico-chemical properties, structure, function, target and source of origin. The synthetic analogues produced either with suitable chemical modifications or with the use of suitable delivery systems are projected to eliminate the constraints of toxicity and poor stability commonly linked with natural AMPs. The concept of peptidomimetics is gaining ground around the world nowadays. Among the delivery systems, nanoparticles are emerging as potential delivery tools for AMPs, amplifying their utility against a variety of pathogens. In the present review, the broad classification of various AMPs, their mechanism of action (MOA), challenges associated with AMPs, current applications, and novel strategies to overcome the limitations have been discussed., Competing Interests: Declaration of competing interest None., (Copyright © 2022. Published by Elsevier B.V.)

Although interest in stabilized α-helical peptides as next-generation therapeutics for modulating biomolecular interfaces is increasing, peptides have limited functionality and stability due to their small size. In comparison, α-helical ligands based on proteins can make steric clash with targets due to their large size. Here, we report the design of a monomeric pseudo-isolated α-helix (mPIH) system in which proteins behave as if they are peptides. The designed proteins contain α-helix ligands that do not require any covalent chemical modification, do not have frayed ends, and importantly can make sterically favorable interactions similar to isolated peptides. An optimal mPIH showed a more than 100-fold increase in target selectivity, which might be related to the advantages in conformational selection due to the absence of frayed ends. The α-helical ligand in the mPIH displayed high thermal stability well above human body temperature and showed reversible and rapid folding/unfolding transitions. Thus, mPIH can become a promising protein-based platform for developing stabilized α-helix pharmaceuticals.

Vesicles such as liposomes, polymersomes, and exosomes have been widely used as drug delivery carriers; however, peptide vesicles (peptidesomes) despite their potential utility are far less well developed. Peptidesomes are distinctive because peptides play dual roles as a self-assembly building block and a bioactive functional unit. In order for peptidesomes to become successful nanodrugs, the issues related to differences in nanostructural properties between in vitro and in vivo conditions should be addressed. Here, we delineate a multivariate approach to feedback control the structures of peptide building blocks, nanoparticle size, drug loading process, nanoparticle aggregation, cytotoxicity, cell targeting capability, endosome disruption function, protease resistance, and in vivo performance, which eventually enabled the successful development of a highly efficacious peptidesome for in vivo cancer therapy. This study lays the groundwork for the successful in vivo translation of peptide nanodrugs., Competing Interests: The authors declare the following financial interests/personal relationships which may be considered as potential competing interests: Yong-beom Lim has patent pending to 10.13039/501100002573Yonsei University, Office of research affairs/University industry foundation., (© 2022 The Authors.)

Contribution of liquid water content (LWC) to the levels of the carcinogenic particulate nitro(so) compounds and the chemistry affecting LWC were investigated based on the observation of seven nitrosamines and two nitramines in rural (Seosan) and urban (Seoul) area in South Korea during October 2019 and a model simulation. The concentrations of both the total nitrosamines and nitramines were higher in Seosan (12.48 ± 16.12 ng/m 3 and 0.65 ± 0.71 ng/m 3 , respectively) than Seoul (7.41 ± 13.59 ng/m 3 and 0.24 ± 0.15 ng/m 3 , respectively). The estimated LWC using a thermodynamic model in Seosan (12.92 ± 9.77 μg/m 3 ) was higher than that in Seoul (6.20 ± 5.35 μg/m 3 ) mainly due to higher relative humidity (75 ± 9% (Seosan); 62 ± 10% (Seoul)) and higher concentrations of free ammonia (0.13 ± 0.09 μmol/m 3 (Seosan); 0.08 ± 0.01 μmol/m 3 (Seoul)) and total nitric acid (0.09 ± 0.07 μmol/m 3 (Seosan); 0.04 ± 0.02 μmol/m 3 (Seoul)) in Seosan while neither fog nor rain occurred during the sampling period. The relatively high concentrations of the particulate nitrosamines (>30 ng/m 3 ) only observed probably due to the higher LWC (>10 μg/m 3 ) in Seosan. It implies that aqueous phase reactions involving NO 2 and/or uptake from the gas phase enhanced by LWC could be promoted in Seosan. Strong correlation between the concentrations of nitrosodi-methylamine (NDMA), an example of nitrosamines, simulated by a kinetic box model including the aqueous phase reactions and the measured concentration of NDMA in Seosan (R = 0.77; 0.37 (Seoul)) indicates that the aqueous phase reactions dominantly enhanced the NDMA concentrations in Seosan. On the other hand, it is estimated that the formation of nitrosamines by aqueous phase reaction was not significant due to the relatively lower LWC in Seoul compared to that in Seosan. Furthermore, it is presumed that nitramines are mostly emitted from the primary emission sources. This study implies that the concentration of the particulate nitrosamines can be promoted by aqueous phase reaction enhanced by LWC., (Copyright © 2022 Elsevier Ltd. All rights reserved.)

The maximum degree of bending that can be tolerated by the rigid rod-like α-helix remains unknown; however, it should be very difficult or even impossible to make α-helices with varying degrees of curvature in folded proteins. As an experimentally tractable model, here we utilize cyclic proteins and peptides to determine the maximum possible bending in the α-helix. We artificially enforced bending in the α-helices by using variously sized macrocycles and compared the structural characteristics of the macrocycles with those of their linear counterparts. This differential analysis reveals that the radius of curvature (RC) for the maximally bent α-helix is approximately 10 times smaller than those of typical α-helices found in natural proteins. Together with the novel finding of the limit of α-helix deformation, excessively bent α-helices can be further utilized in designing de novo peptides and proteins with unique structures and peculiar functions.

Objectives: Childhood adversity is a risk factor for anxiety symptoms, but it affects anxiety symptoms in attention-deficit/hyperactivity disorder (ADHD). The current study aimed to examine the association between childhood adversity and anxiety symptoms in participants with and without ADHD., Methods: Data were obtained from a school-based epidemiological study of 1017 randomly selected children and adolescents. The ADHD and non-ADHD groups were divided using the Diagnostic Interview Schedule for Children Predictive Scale (DPS). The DPS was also used to assess comorbidities such as anxiety and mood disorders. The childhood adversities were assessed using the Early Trauma Inventory Self Report-Short Form, and the anxiety symptoms were assessed using the Screen for Child Anxiety Related Disorders. Linear and logistic regression models were used to investigate the association between childhood adversity and anxiety in the ADHD and non-ADHD groups with adjustments for age and sex., Results: This study found that the ADHD group did not show any significant association between anxiety symptoms and childhood adversities, whereas the non-ADHD group always showed a significant association. In a subgroup analysis of the non-ADHD group, the normal group without any psychiatric disorders assessed with DPS demonstrated a statistically significant association between childhood adversities and anxiety symptoms. These results were consistent with the association between childhood adversities and anxiety disorders assessed using DPS, as shown by logistic regression., Conclusion: The association between anxiety symptoms and childhood adversities statistically disappears in ADHD; ADHD may mask or block the association. Further longitudinal research is necessary to investigate this relationship., Competing Interests: Conflicts of Interest The authors have no potential conflicts of interest to disclose., (Copyright © 2021 Korean Academy of Child and Adolescent Psychiatry.)

There is growing evidence that the accumulation of DNA damage induced by fine particulate matter (PM 2.5 ) exposure is an underlying mechanism of pulmonary disease onset and progression. However, there is a lack of experimental evidence on whether common factors (age, gender) affect PM 2.5 induced genomic damage. Here, we assessed the DNA damage potency of PM 2.5 using conventional genotoxicity testing in old male and female mice aged 8 and 40 weeks. Mice were intratracheally instilled with diesel exhaust PM 2.5 (DEP, NIST SRM 1650b), twice a week for 4 weeks. Exposure to DEP was not associated with an increase in the frequency of micronucleated polychromatic erythrocytes and did not induce a systemic genotoxic effect in the bone marrow. Meanwhile, the results from the comet assay showed a significant increase in DNA damage in DEP exposed mouse lung specimens. The positive relationship between DEP exposure and DNA damage is stronger in the older than in the younger group. Statistical analysis showed that there was a modifying effect of age on the association between PM 2.5 exposure and DNA damage. Our results suggest that the age factor should be considered to better understand the cellular adverse effects of PM 2.5 .

Several epidemiological studies concluded that inhalation of diesel exhaust particles (DEP) is associated with an increase in the relative risk of lung cancer. In vitro research evaluating the genetic damage and/or changes in gene expression have been attempted to explain the relationship between DEP exposure and carcinogenicity. However, to date, investigations have been largely confined to studies in immortalized or tumorigenic epithelial cell models. Few studies have investigated damage at the chromosomal level to DEP exposure in normal cell lines. Here, we present the genotoxic effects of DEP in normal cells (embryonic human lung fibroblasts) by conventional genotoxicity testing (micronuclei (MN) and comet assay). We show the differentially expressed genes and enriched pathways in DEP-exposed WI-38 cells using RNA sequencing data. We observed a significant increase in single-strand DNA breaks and the frequency of MN in DEP-exposed cells in a dose-dependent manner. The differentially expressed genes following DEP exposure were significantly enriched in the pathway for responding to xenobiotics and DNA damage. Taken together, these results show that DEP exposure induced DNA damage at the chromosomal level in normal human lung cells and provide information on the expression of genes associated with genotoxic stress.

The aggregation and accumulation of amyloid-β (Aβ) peptides is a characteristic pathology for Alzheimer's disease (AD). Although noninvasive therapies involving stimulation by electric field (EF) have been reported, the efficiency of Aβ disaggregation needs to be further improved for this strategy to be used in clinical settings. In this study, we show that an electrode based on a vertical nanowire electrode array (VNEA) is far more superior to a typical flat-type electrode in disaggregating Aβ plaques. The enhanced disaggregation efficiency of VNEA is due to the formation of high-strength local EF between the nanowires, as verified by in silico and empirical evidence. Compared with those of the flat electrode, the simulation data revealed that 19.8-fold and 8.8-fold higher EFs are generated above and between the nanowires, respectively. Moreover, empirical cyclic voltammetry data demonstrated that VNEA had a 2.7-fold higher charge capacity than the flat electrode; this is associated with the higher surface area of VNEA. The conformational transition of Aβ peptides between the β-sheet and α-helix could be sensitively monitored in real time by the newly designed in situ circular dichroism instrument. This highly efficient EF-configuration of VNEA will lower the stimulation power for disaggregating the Aβ plaques, compared to that of other existing field-mediated modulation systems. Considering the complementary metal-oxide-semiconductor-compatibility and biocompatible strength of the EF for perturbing the Aβ aggregation, our study could pave the way for the potential use of electric stimulation devices for in vivo therapeutic application as well as scientific studies for AD.

Detecting amyloid beta (Aβ) in unpurified blood to diagnose Alzheimer's disease (AD) is challenging owing to low concentrations of Aβ and the presence of many other substances in the blood. Here, we propose a 3D sensor for AD diagnosis using blood plasma, with pairs of 3D silicon micropillar electrodes with a comprehensive circuit configuration. The sensor is developed with synthesized artificial peptide and impedance analysis based on a maximum signal-to-noise ratio. Its sensitivity and selectivity were verified using an in vitro test based on samples of human blood serum, which showed its feasibility for application in diagnosis of AD by testing blood plasma of the AD patient. The 3D sensor is designed to improve reliability by checking the impedance of each pair multiple times via constructing a reference pair and a working pair on the same sensor. Therefore, we demonstrate the ability of the 3D sensor to recognize cases of AD using blood plasma and introduce its potential as a self-health care sensor for AD patients., Competing Interests: The authors declare no competing financial interest., (© 2020 American Chemical Society.)

In vitro erythroid cultures from human hematopoietic stem cells produce immature red blood cells (RBCs) called reticulocytes, which are important for RBCs production, and are widely used in scientific studies of malaria pathology, hematological diseases and protein translation. However, in vitro reticulocyte cultures contain expelled cell nuclei and erythroblasts as undesirable by-products and current purification methods such as density gradient centrifugation and fluorescence-activated cell sorting (FACS) are not optimal for integrated bioprocessing and downstream therapeutic applications. Developments in Dean flow fractionation (DFF) and deterministic lateral displacement (DLD) microfluidic sorting methods are ideal alternatives due to label-free size sorting, throughput scalability and low manufacturing cost. DFF sorting of reticulocytes from whole erythroid culture showed a 2.4-fold increase in cell recovery compared to FACS albeit with a lower purity; DLD sorting showed comparable cell recovery and purity with FACS using an inverse-L pillar structure to emphasize size and deformability sorting of reticulocytes. The viability and functional assurance of purified reticulocytes showed conserved cell deformability and supported the propagation of malaria parasites. Collectively, our study on label-free RBCs isolation represents a significant technical advancement towards developing in vitro generated viable human RBCs, opening opportunities for close-loop cell manufacturing, downstream therapeutic and research purposes.

Aim: Colon cancer is one of the leading causes of cancer-related mortality. However, specific biomarkers for its diagnosis or treatment are not established well., Methods: We developed a colon-cancer specific peptide probe using phage display libraries. We validated the specificity of this probe to colon cancer cells with immunohistochemical staining and FACS analysis using one normal cell and five colon cancer cell lines., Results: This peptide probe maintained binding affinity even after serum incubation. For therapeutic applications, this peptide probe was conjugated to hematoporphyrin, a photosensitizer, which showed a significantly enhanced cellular uptake and high photodynamic effect to kill tumor cells. As another application, we made a nanoparticle modified from the peptide probe. It efficiently delivered SN-38, an anticancer drug, into tumor cells, and its tumor-targeting ability was observed in vivo after intravenous injection to the same xenograft model., Conclusion: The noble dodecapeptide probe can be a promising candidate for both colon tumor diagnosis and targeted drug delivery., Competing Interests: Declaration of Competing Interest The authors declare no potential conflicts of interest., (Copyright © 2020 The Authors. Published by Elsevier Inc. All rights reserved.)

Background and objectives : Breast cancer is a common cancer in women and has been the fourth leading cause of death in Taiwanese women. Risk factors for breast cancer include family history of breast cancer, genetic factors, and not breastfeeding. Several studies have reported an association between repeated inflammation at a young age, especially among lactating women, and cancer; however, the number of studies about the association of mastitis and breast cancer in nonlactating women is still limited. Therefore, the aim of this study was to determine the relationship between mastitis in women aged ≥40 years and breast cancer. Materials and Methods: This was a retrospective cohort study design. The data source was the Longitudinal Health Insurance Database 2010 (LHID 2010), comprising data collected by Taiwan's National Health Insurance program. Cases of newly diagnosed mastitis in women aged ≥40 years (ICD-9-CM code = 611.0) were selected from the years 2010 to 2012. Women not diagnosed with mastitis were selected as the control group, and their data for the years 2009 to 2013 were obtained through the database. In addition, the non-mastitis group was matched 1:10 by age. Results : A total of 8634 participants were selected from the LHID 2010, which included 734 cases with mastitis and 7900 cases without mastitis. After adjustment for age, hypertension, hyperlipidemia, diabetes, hypothyroidism, and autoimmune diseases, the Cox proportional hazard model showed that patients with mastitis had a higher risk of breast cancer (aHR = 3.71, 95% CI = 1.9-7.02) compared with the non-mastitis group. The Kaplan-Meier curve also showed that women with mastitis had a higher risk of developing breast cancer. Conclusions : This study confirmed that women with mastitis have a higher risk of developing breast cancer. Therefore, women aged ≥40 years could reduce breast cancer risk by taking precautions to prevent mammary gland infection and mastitis.

Purpose: The delivery of high-dose hypofractionated radiation to a tumor induces vascular damage, but little is known about the responses of vascular endothelial cells to high-dose radiation. We examined whether high-dose irradiation alters vascular endothelial growth factor (VEGF) signaling, which is a critical regulator of the functional integrity and viability of vascular endothelial cells., Methods and Materials: Human umbilical vein endothelial cells and human coronary artery endothelial cells were treated with 5, 10, 20, or 30 Gy ionizing radiation (IR). Expression values of VEGFA mRNA were analyzed by real-time polymerase chain reaction at 4 hours after irradiation and normalized to the average value of mock-irradiated human umbilical vein endothelial cell or human coronary artery endothelial cell controls., Results: Irradiation with doses higher than 10 Gy causes an acute increase in VEGFA transcript levels, which was accompanied by activation of the PERK/eIF2α/activating transcription factor 4 (ATF4) pathway in human vascular endothelial cells. ATF4 knockdown with siRNA completely prevented the IR-induced upregulation of VEGFA transcripts, and chromatin immunoprecipitation assays demonstrated that ATF4 binding to the VEGFA locus was enriched in response to IR. Postirradiation treatment with an intracellular inhibitor of VEGF signaling significantly enhances high-dose IR-induced apoptosis in human vascular endothelial cells., Conclusions: Human vascular endothelial cells activate PERK/eIF2α/ATF4/VEGF signaling in response to high-dose IR to mitigate the apoptotic response. Thus, for cancer treatment, intracellular inhibitors of VEGF signaling could be employed to enhance stereotactic body radiation therapy-induced vascular damage, which would augment tumor cell death., (Copyright © 2020 Elsevier Inc. All rights reserved.)

Understanding the intermediates or transition states in organic reactions has made it possible to develop theories and to synthesize important compounds. In contrast to organic reaction intermediates and even protein folding intermediates, the intermediates of peptide/protein self-assembly are not very well understood. Here we report that the self-assembly kinetics of linear heterochiral peptides are significantly slower than those of the corresponding homochiral peptides, which enables direct microscopic observation of assembly intermediates. By designing racemic or asymmetric heterochiral peptides, we were able to discover unusual mixed helical ( MP -helix) and overtwisted intermediates. The convergence of equilibrium morphology between the homochiral and heterochiral peptides enables us to reasonably deduce the unobservable intermediates of rapidly assembling homochiral peptides. By utilizing the discovered information about the assembly intermediates, we were able to develop a functional NMR alignment medium that enables the measurement of residual dipolar couplings (RDCs) in a time-dependent manner. Although much less studied than their cyclic counterparts, the linear form of heterochiral peptides provides a means of obtaining a more in-depth understanding of the self-assembly pathway and of developing sophisticated bottom-up materials.

Plasmodium falciparum malaria-infected red blood cells (IRBCs), or erythrocytes, avoid splenic clearance by adhering to host endothelium. Upregulation of endothelial receptors intercellular adhesion molecule-1 (ICAM-1) and cluster of differentiation 36 (CD36) are associated with severe disease pathology. Most in vitro studies of IRBCs interacting with these molecules were conducted at room temperature. However, as IRBCs are exposed to temperature variations between 37°C (body temperature) and 41°C (febrile temperature) in the host, it is important to understand IRBC-receptor interactions at these physiologically relevant temperatures. Here, we probe IRBC interactions against ICAM-1 and CD36 at 37 and 41°C. Single bond force-clamp spectroscopy is used to determine the bond dissociation rates and hence, unravel the nature of the IRBC-receptor interaction. The association rates are also extracted from a multiple bond flow assay using a cellular stochastic model. Surprisingly, IRBC-ICAM-1 bond transits from a catch-slip bond at 37°C toward a slip bond at 41°C. Moreover, binding affinities of both IRBC-ICAM-1 and IRBC-CD36 decrease as the temperature rises from 37 to 41°C. This study highlights the significance of examining receptor-ligand interactions at physiologically relevant temperatures and reveals biophysical insight into the temperature dependence of P. falciparum malaria cytoadherent bonds., (Copyright © 2019 Biophysical Society. Published by Elsevier Inc. All rights reserved.)

This paper presents the first CMOS Vascular Endothelial Growth Factor (VEGF) sensor for cancer diagnosis directly from human blood. The sensor incorporates a peptide aptamer-based microneedle that allows the detection of electrochemical reactions with VEGF. This results in a capacitance change between the microneedles and then reads out by a two-step capacitance-to-digital converter (CDC). The proposed two-step CDC consists of a coarse 5b slope ADC and a fine 14b continuous-time delta-sigma modulator (CTDSM). During slow peptide-binding, the slope ADC performs a coarse conversion and the results are used to adjust the current level of the stimulator. After settling of the peptide-binding, based on an adjusted stimulation current, the CTDSM measures the small capacitance changes of the sensor. The prototype chip is fabricated in a 65-nm CMOS process, occupying a 0.87 mm 2 active area. The power consumption is 270 muW. Thanks to the two-step approach, this work achieves a wide dynamic range of 18.3b, covering a large sensor-to-sensor variation. It also achieves a peak resolution of 13.7b, while maintaining errors in 1 to 100 nF baseline capacitance. The overall sensor system successfully detects the VEGF in both phosphate-buffered saline (PBS) and human blood serum. Without the use of precision instruments, this work achieves a resolution of 15 fM [Formula: see text] in range of 0.1 to 1000 pM and denotes the clear VEGF selectivity at 40× in PBS and 5× in the blood serum compared to other proteins (IgG, Con A, and cholera toxin).

Self-assembling peptides are biomedical materials with unique structures that are formed in response to various environmental conditions. Governed by their physicochemical characteristics, the peptides can form a variety of structures with greater reactivity than conventional non-biological materials. The structural divergence of self-assembling peptides allows for various functional possibilities; when assembled, they can be used as scaffolds for cell and tissue regeneration, and vehicles for drug delivery, conferring controlled release, stability, and targeting, and avoiding side effects of drugs. These peptides can also be used as drugs themselves. In this review, we describe the basic structure and characteristics of self-assembling peptides and the various factors that affect the formation of peptide-based structures. We also summarize the applications of self-assembling peptides in the treatment of various diseases, including cancer. Furthermore, the in-cell self-assembly of peptides, termed reverse self-assembly, is discussed as a novel paradigm for self-assembling peptide-based nanovehicles and nanomedicines.

Liver damage upon exposure to ionizing radiation, whether accidental or because of therapy can contribute to liver dysfunction. Currently, radiation therapy is used for various cancers including hepatocellular carcinoma; however, the treatment dose is limited by poor liver tolerance to radiation. Furthermore, reliable biomarkers to predict liver damage and associated side-effects are unavailable. Here, we investigated fibrinogen-like 1 (FGL1)-expression in the liver and plasma after radiation exposure. We found that 30 Gy of liver irradiation (IR) induced cell death including apoptosis, necrosis, and autophagy, with fibrotic changes in the liver occurring during the acute and subacute phase in mice. Moreover, FGL1 expression pattern in the liver following IR was associated with liver damage represented by injury-related proteins and oxidative stress markers. We confirmed the association between FGL1 expression and hepatocellular injury by exposing human hepatocytes to radiation. To determine its suitability, as a potential biomarker for radiation-induced liver injury, we measured FGL1 in the liver tissue and the plasma of mice following total body irradiation (TBI) or liver IR. In TBI, FGL1 showed the highest elevation in the liver compared to other major internal organs including the heart, lung, kidney, and intestine. Notably, plasma FGL1 showed good correlation with radiation dose by liver IR. Our data revealed that FGL1 upregulation indicates hepatocellular injury in response to IR. These results suggest that plasma FGL1 may represent a potential biomarker for acute and subacute radiation exposure to the liver.

Drug repositioning has garnered attention as an alternative strategy to the discovery and development of novel anticancer drug candidates. In this study, we screened 321 FDA-approved drugs against nonirradiated and irradiated MCF-7 cells, revealing that aripiprazole, a dopamine receptor D2 (D2R) partial agonist, enhances the radiosensitivity of MCF-7 cells. Unexpectedly, D2R-selective antagonist treatment significantly enhanced the radiosensitizing effects of aripiprazole and prevented aripiprazole-induced 5' adenosine monophosphate-activated protein kinase (AMPK) phosphorylation. Direct AMPK activation with A769662 treatment blunted the radiosensitizing effects of aripiprazole. These results indicate that aripiprazole has potential as a radiosensitizing drug. Furthermore, prevention of D2R/AMPK activation might enhance these anticancer effects of aripiprazole in breast cancer cells., (© 2019 The Authors. Published by FEBS Press and John Wiley & Sons Ltd.)

Mechanical cues influence pluripotent stem cell differentiation, but the underlying mechanisms are not well understood. Mouse embryonic stem cells (mESCs) exhibit unusual cytomechanical properties, including low cell stiffness and attenuated responses to substrate rigidity, but the underlying structural basis remains obscure. Using super-resolution microscopy to investigate the actin cytoskeleton in mESCs, we observed that the actin cortex consists of a distinctively sparse and isotropic network. Surprisingly, the architecture and mechanics of the mESC actin cortex appear to be largely myosin II-independent. The network density can be modulated by perturbing Arp2/3 and formin, whereas capping protein (CP) negatively regulates cell stiffness. Transient Arp2/3-containing aster-like structures are implicated in the organization and mechanical homeostasis of the cortical network. By generating a low-density network that physically excludes myosin II, the interplay between Arp2/3, formin, and CP governs the nanoscale architecture of the actin cortex and prescribes the cytomechanical properties of mESCs., (Copyright © 2019 The Author(s). Published by Elsevier Inc. All rights reserved.)

Cluh is a cytosolic protein that is known to specifically bind the mRNAs of nuclear-encoded mitochondrial proteins and play critical roles in mitochondrial biogenesis. Here, we report the role of Cluh in adipogenesis. Our study shows that mRNA expression of Cluh is stimulated during adipogenesis, and that cAMP/Creb signalling increases its transcription. Cluh depletion impaired proper adipocyte differentiation, with reductions seen in lipid droplets and adipogenic marker gene expression. Interestingly, the inductions of the brown adipocyte-specific genes, Ucp1, Cidea and Cox7a1, are severely blocked by Cluh depletion during brown adipogenesis. Mitochondrial respiration and the stability of mRNAs encoding mitochondrial proteins are reduced by Cluh depletion during brown adipogenesis. These results suggest that Cluh, which is induced during adipogenesis, promotes the post-transcriptional regulation of mitochondrial proteins and supports differentiation.

Pelvic and abdominal radiotherapy plays an important role in eradication of malignant cells; however, it also results in slight intestinal injury. The apoptosis of cells in the intestinal epithelium is a primary pathological factor that initiates radiation-induced intestinal injury. Auranofin, a gold-containing triethylphosphine, was approved for the treatment of rheumatoid arthritis, and its therapeutic application has been expanded to a number of other diseases, such as parasitic infections, neurodegenerative disorders, AIDS, and bacterial infections. Recently, a treatment strategy combining the use of auranofin and ionizing radiation aimed at increasing the radiosensitivity of cancer cells was proposed for improving the control of local cancers. In this study, we evaluated the effect of auranofin on the radiosensitivity of intestinal epithelial cells. The treatment with a combination of 1 μM auranofin and 5 Gy ionizing radiation showed clear additive effects on caspase 3 cleavage and apoptotic DNA fragmentation in IEC-6 cells, and auranofin administration significantly aggravated the radiation-induced intestinal injury in mice. Auranofin treatment also resulted in the activation of the unfolded protein response and in the inhibition of thioredoxin reductase, which is a key component of the cellular antioxidant system. Pre-treatment with N-acetyl cysteine, a well-known scavenger of reactive oxygen species, but not with a chemical chaperone, which inhibits endoplasmic reticulum stress and the ensuing unfolded protein response, significantly reduced the radiosensitizing effects of auranofin in the IEC-6 cells. In addition, transfection of IEC-6 cells with a small interfering RNA targeted against thioredoxin reductase significantly enhanced the radiosensitivity of these cells. These results suggest that auranofin-induced radiosensitization of intestinal epithelial cells is mediated through oxidative stress caused by the deregulation of thioredoxin redox system, and auranofin treatment can be an independent risk factor for the development of acute pelvic radiation disease.

The real-time selective detection of disease-related markers in blood using biosensors has great potential for use in the early diagnosis of diseases and infections. However, this potential has not been realized thus far due to difficulties in interfacing the sensor with blood and achieving transparent circuits that are essential for detecting of target markers (e.g., protein, ions, etc.) in a complex blood environment. Herein, we demonstrate the real-time detection of a specific protein and ion in blood without a skin incision. Complementary metal-oxide-semiconductor technology was used to fabricate silicon micropillar array (SiMPA) electrodes with a height greater than 600 μm, and the surface of the SiMPA electrodes was functionalized with a self-assembling artificial peptide (SAP) as a receptor for target markers in blood, i.e., cholera toxin (CTX) and mercury(II) ions (Hg). The detection of CTX was investigated in both in vitro (phosphate-buffered saline and human blood serum, HBO model) and in vivo (mouse model) modes via impedance analysis. In the in vivo mode, the SiMPA pierces the skin, comes into contact with the blood system, and creates comprehensive circuits that include all the elements such as electrodes, blood, and receptors. The SiMPA achieves electrically transparent circuits and, thus, can selectively detect CTX in the blood in real time with a high sensitivity of 50 pM and 5 nM in the in vitro and in vivo modes, respectively. Mercury(II) ions can also be detected in both the in vitro and the in vivo modes by changing the SAP. The results illustrate that a robust sensor that can detect a variety of molecular species in the blood system in real time that will be helpful for the early diagnosis of disease and infections.

Probing the intermolecular interactions and local environments of self-assembled peptide nanostructures (SPNs) is crucial for a better understanding of the underlying molecular details of self-assembling phenomena. In particular, investigation of the hydration state is important to understand the nanoscale structural and functional characteristics of SPNs. In this report, we examined the local hydration environments of SPNs in detail to understand the driving force of the discrete geometric structural self-assembling phenomena for peptide nanostructures. Advanced electron paramagnetic resonance spectroscopy was used to probe the hydrogen bond formation and geometry as well as the hydrophobicity of the local environments at various spin-labeled sites in SPNs. The experimental results supplement the sparse experimental data regarding local structures of SPNs, such as the hydrogen bonding and the hydrophobicity of the local environment, providing important information on the formation of SPNs, which have immense potential for bioactive materials., Competing Interests: The authors declare no competing financial interest.

Antimalarial drug discovery expands on targeted and phenotype-based screening of potential inhibitory molecules to ascertain overall efficacy, phenotypic characteristics and toxicity, prior to exploring pharmacological optimizations. Candidate inhibitors may have varying chemical properties, thereby requiring specific reconstitution conditions to ensure solubility, stability or bioavailability. Hence, a variety of solvents, buffers, detergents and stabilizers become part of antimalarial efficacy assays, all of which, above certain threshold could interfere with parasite viability, invasion or red blood cell properties leading to misinterpretation of the results. Despite their routine use across malaria research laboratories, there is no documentation on non-toxic range for common constituents including DMSO, glycerol, ethanol and methanol. We herein constructed a compatibility reference guide for 14 such chemicals and estimated their Permissible Limit against P. falciparum asexual stages at which viability and replication of parasites are not compromised. We also demonstrate that at the estimated Permissible Limit, red blood cells remain healthy and viable for infection by merozoites. Taken together, this dataset provides a valuable reference tool for the acceptable concentration range for common chemicals during in vitro antimalarial tests.

Peptide-oligonucleotide conjugates (POCs) are interesting molecules as they covalently combine 2 of the most important biomacromolecules. Sometimes, the synthesis of POCs involves unexpected difficulties; however, POCs with self-assembling propensity are even harder to synthesize and purify. Here, we show that solid-phase peptide fragment condensation combined with thiol-maleimide or copper-catalyzed azide-alkyne cycloaddition click chemistries is useful for the syntheses of self-assembling POCs. We describe guidelines for the selection of reactive functional groups and their placement during the conjugation reaction and consider the cost-effectiveness of the reaction. Purification is another important challenge during the preparation of POCs. Our results show that polyacrylamide gel electrophoresis under denaturing conditions is most suitable to recover a high yield of self-assembling POCs. This report provides the first comprehensive study of the preparation of self-assembling POCs, which will lay a foundation for the development of elegant and sophisticated molecular assemblies., (Copyright © 2018 European Peptide Society and John Wiley & Sons, Ltd.)

The development of personalized cancer therapy depends on a robust system to monitor the patient's individual response to anticancer treatment. Anticancer drug efficacy has been tested on circulating tumor cells (CTCs) derived from patient blood samples after ex vivo expansion into CTC clusters. Current attempts to culture these primary cancer cells focus on long-term maintenance under growth factor supplements into cell lines, which usually takes >6 months and results in a CTC expansion efficiency of <20%. We recently developed a simple but unique microfluidics-based culture approach that requires minimal preprocessing (∼30 min) and does not require prior enrichment of CTCs or depend on the use of growth factor supplements. The approach capitalizes on co-culture of immune cells from the same patient blood sample within specially designed microwells that promote CTC cluster formation within 2 weeks, with an overall cluster formation success rate of ∼50%. Drug screening is facilitated by the incorporation of a gradient generator for parallel exposure to two or more drugs at various concentrations. Owing to the cost-effectiveness and less-invasive nature of this procedure, routine monitoring of disease progression can be achieved. The described microfluidics system can be operated with a single syringe pump to introduce drug compounds (which takes ∼6 min), followed by incubation of the CTC clusters for 48 h before analysis. In addition to its applications in biomedical research, the rapid readout of our platform will enable clinicians to assess or predict a patient's response to various therapeutic strategies, so as to enable personalized or precision therapy.

The Si-coated SiC (Si-SiC) composite nanoparticle was prepared by non-transferred arc thermal plasma processing of solid-state synthesized SiC powder and was used as a sintering additive for SiC ceramic formation. Sintered SiC pellet was prepared by spark plasma sintering (SPS) process, and the effect of nano-sized Si-SiC composite particles on the sintering behavior of micron-sized SiC powder was investigated. The mixing ratio of Si-SiC composite nanoparticle to micron-sized SiC was optimized to 10 wt%. Vicker's hardness and relative density was increased with increasing sintering temperature and holding time. The relative density and Vicker's hardness was further increased by reaction bonding using additional activated carbon to the mixture of micron-sized SiC and nano-sized Si-SiC. The maximum relative density (97.1%) and Vicker's hardness (31.4 GPa) were recorded at 1800 °C sintering temperature for 1 min holding time, when 0.2 wt% additional activated carbon was added to the mixture of SiC/Si-SiC.

The interactions between graphene oxide (GO) and various biological entities have been actively investigated in recent years, resulting in numerous potential bioapplications of these nanomaterials. Despite this, the biological interactions between GO and disease-causing protozoan parasites have not been well elucidated and remain relatively unexplored. Here, we investigate the in vitro interactions between GO nanosheets and a particular species of malaria parasites, Plasmodium falciparum (P. falciparum). We hypothesize that GO nanosheets may exhibit antimalarial characteristic via action mechanisms of physical obstruction of P. falciparum parasites as well as nutrient depletion. To ascertain this, we characterize the physical interactions between GO nanosheets, red blood cells (RBCs), and malarial parasites as well as the adsorption of several biomolecules necessary for parasitic survival and growth on GO nanosheets. Subsequent to establishing the origin of this antimalarial behavior of GO nanosheets, their efficiency in inhibiting parasite invasion is evaluated. We observe that GO nanosheets at various tested concentrations significantly inhibit the invasion of malaria parasites into RBCs. Furthermore, GO nanosheets delay parasite progression from the ring to the trophozoite stage. Overall, this study may further shed light on the graphene-parasite interactions and potentially facilitate the development of nanomaterial-based strategies for combating malaria.

The adhesion of malaria infected red blood cells (iRBCs) to host endothelial receptors in the microvasculature, or cytoadhesion, is associated with severe disease pathology such as multiple organ failure and cerebral malaria. Malaria iRBCs have been shown to bind to several receptors, of which intercellular adhesion molecule 1 (ICAM-1) upregulation in brain microvasculature is the only one correlated to cerebral malaria. We utilize a biophysical approach to study the interactions between iRBCs and ICAM-1. At the single molecule level, force spectroscopy experiments reveal that ICAM-1 forms catch bond interactions with Plasmodium falciparum parasite iRBCs. Flow experiments are subsequently conducted to understand multiple bond behavior. Using a robust model that smoothly transitions between our single and multiple bond results, we conclusively demonstrate that the catch bond behavior persists even under flow conditions. The parameters extracted from these experimental results revealed that the rate of association of iRBC-ICAM-1 bonds are ten times lower than iRBC-CD36 (cluster of differentiation 36), a receptor that shows no upregulation in the brains of cerebral malaria patients. Yet, the dissociation rates are nearly the same for both iRBC-receptor interactions. Thus, our results suggest that ICAM-1 may not be the sole mediator responsible for cytoadhesion in the brain.

The extensive modification of Plasmodium falciparum-infected erythrocytes by variant surface antigens plays a major role in immune evasion and malaria-induced pathology. Here, using high-resolution microscopy, we visualize the spatio-temporal expression dynamics of STEVOR, an important variant surface antigens family, in a stage-dependent manner. We demonstrate that it is exported to the cell surface where protein molecules cluster and preferentially localize in proximity to knobs. Quantitative evidence from our force measurements and microfluidic assays reveal that STEVOR can effectively mediate the formation of stable, robust rosettes under static and physiologically relevant flow conditions. Our results extend previously published studies in P. falciparum and emphasize the role of STEVOR in rosetting, an important contributor to disease pathology., (© 2016 John Wiley & Sons Ltd.)

Yes-associated protein (YAP) is regulated by mechanical cues via the interaction of the Hippo pathway with cytoskeleton. Previous studies showed that YAP plays a role in regulating the actomyosin network by suppressing Rho GTPase in medaka fish. Here, we identify Rho GTPase activating protein 29 (ARHGAP29) as a transcriptional target of YAP in a human gastric cancer cell line. YAP promotes the expression of ARHGAP29 to suppress the RhoA-LIMK-cofilin pathway, destabilizing F-actin. The overexpression of YAP causes cytoskeletal rearrangement by altering the dynamics of F-actin/G-actin turnover, thus promoting migration. In a mouse model, circulating tumor cells (CTCs) exhibit an increased ARHGAP29 RNA level compared with cells at primary tumor sites, and the metastatic potential of CTCs is positively correlated with ARHGAP29 expression. Moreover, increased ARHGAP29 expression is correlated with shortened survival of human gastric cancer patients. Our study provides a model to understand YAP's contribution to cancer metastasis via regulation of actin dynamics., (Copyright © 2017 National University of Singapore. Published by Elsevier Inc. All rights reserved.)

A novel self-assembly strategy for the formation of multicomponent and multicompartment vesicles via the hierarchical assembly of the cyclic peptide and lipid building blocks is reported. The primary driving force underlying the formation of dual-component (i.e., peptide and lipid) heteromultivesicular vesicles (hMVVs) is the differential thermostability between the supramolecular building blocks. Furthermore, the combination of the differential thermostability and charge-based separation further enables the fabrication of the hMVVs that incorporate up to four different components (i.e., two different building blocks and two different encapsulated molecules). The quadruple-component hMVVs consist of cyclic peptides, lipids, negatively charged green fluorescent probes (GFPr), and positively charged red fluorescent probes (RFPr). Intracellular delivery study shows that cellular localization of hMVVs is directed by the function of hMVV envelopes, and the nuclear localization signal (NLS) of peptide vesicles appears to use different cellular pathways depending on the site of action (i.e., extracellular space or cytoplasm). This study provides the hierarchical peptide-based hMVVs with sophisticated architectures and cell delivery characteristics, thus making a step toward artificial cells or viruses.

Multitarget-directed ligands (MTDLs) are hybrid ligands obtained by covalently linking active pharmacophores that can act on different targets. We envision that the concept of MTDLs can also be applied to supramolecular bioinorganic nanohybrid systems. Here, we report the inhibition of multimolecular RNA-protein complexes using multitarget-directed peptide-carbon nanotube hybrids (SPCHs). One of the most well-characterized and important RNA-protein interactions, a Rev-response element (RRE) RNA:Rev protein:Crm1 protein interaction system in human immunodeficiency virus type-1, was used as a model of multimolecular RNA-protein interactions. Although all previous studies have targeted only one of the interaction interfaces, that is, either the RRE:Rev interface or the RRE-Rev complex:Crm1 interface, we here have developed multitarget-directed SPCHs that could target both interfaces because the supramolecular nanosystem could be best suited for inhibiting multimolecular RNA-protein complexes that are characterized by large and complex molecular interfaces. The results showed that the single target-directed SPCHs were inhibitory to the single interface comprised only of RNA and protein in vitro, whereas multitarget-directed SPCHs were inhibitory to the multimolecular RNA-protein interfaces both in vitro and in cellulo. The MTDL nanohybrids represent a novel nanotherapeutic system that could be used to treat complex disease targets.

The first step in the conventional approach to self-assembled biomaterials is to develop well-defined nanostructures in vitro, which is followed by disruption of the preformed nanostructures at the inside of the cell to achieve bioactivity. Here, we propose an inverse strategy to develop in-cell gain-of-function self-assembled nanostructures. In this approach, the supramolecular building blocks exist in a unimolecular/unordered state in vitro or at the outside of the cell and assemble into well-defined nanostructures after cell internalization. We used block copolypeptides of an oligoarginine and a self-assembling peptide as building blocks and investigated correlations among the nanostructural state, antiprion bioactivity, and cytotoxicity. The optimal bioactivity (i.e., the highest antiprion activity and lowest cytotoxicity) was obtained when the building blocks existed in a unimolecular/unordered state in vitro and during the cell internalization process, exerting minimal cytotoxic damage to cell membranes, and were subsequently converted into high-charge-density vesicles in the low pH endosome/lysosomes in vivo, thus, resulting in the significantly enhanced antiprion activity. In particular, the in-cell self-assembly concept presents a feasible approach to developing therapeutics against protein misfolding diseases. In general, the in-cell self-assembly provides a novel inverse methodology to supramolecular bionanomaterials.