Biomedical Applications of CNT-Based Fibers.

Carbon nanotubes (CNTs) have been regarded as emerging materials in various applications. However, the range of biomedical applications is limited due to the aggregation and potential toxicity of powder-type CNTs. To overcome these issues, techniques to assemble them into various macroscopic structures, such as one-dimensional fibers, two-dimensional films, and three-dimensional aerogels, have been developed. Among them, carbon nanotube fiber (CNTF) is a one-dimensional aggregate of CNTs, which can be used to solve the potential toxicity problem of individual CNTs. Furthermore, since it has unique properties due to the one-dimensional nature of CNTs, CNTF has beneficial potential for biomedical applications. This review summarizes the biomedical applications using CNTF, such as the detection of biomolecules or signals for biosensors, strain sensors for wearable healthcare devices, and tissue engineering for regenerating human tissues. In addition, by considering the challenges and perspectives of CNTF for biomedical applications, the feasibility of CNTF in biomedical applications is discussed.

Cold-Responsive Hyaluronated Upconversion Nanoplatform for Transdermal Cryo-Photodynamic Cancer Therapy.

Cryotherapy leverages controlled freezing temperature interventions to engender a cascade of tumor-suppressing effects. However, its bottleneck lies in the standalone ineffectiveness. A promising strategy is using nanoparticle therapeutics to augment the efficacy of cryotherapy. Here, a cold-responsive nanoplatform composed of upconversion nanoparticles coated with silica - chlorin e6 - hyaluronic acid (UCNPs@SiO2-Ce6-HA) is designed. This nanoplatform is employed to integrate cryotherapy with photodynamic therapy (PDT) in order to improve skin cancer treatment efficacy in a synergistic manner. The cryotherapy appeared to enhance the upconversion brightness by suppressing the thermal quenching. The low-temperature treatment afforded a 2.45-fold enhancement in the luminescence of UCNPs and a 3.15-fold increase in the photodynamic efficacy of UCNPs@SiO2-Ce6-HA nanoplatforms. Ex vivo tests with porcine skins and the subsequent validation in mouse tumor tissues revealed the effective HA-mediated transdermal delivery of designed nanoplatforms to deep tumor tissues. After transdermal delivery, in vivo photodynamic therapy using the UCNPs@SiO2-Ce6-HA nanoplatforms resulted in the optimized efficacy of 79% in combination with cryotherapy. These findings underscore the Cryo-PDT as a truly promising integrated treatment paradigm and warrant further exploring the synergistic interplay between cryotherapy and PDT with bright upconversion to unlock their full potential in cancer therapy.

Neural correlates of model-based behavior in internet gaming disorder and alcohol use disorder.

Background: An imbalance between model-based and model-free decision-making systems is a common feature in addictive disorders. However, little is known about whether similar decision-making deficits appear in internet gaming disorder (IGD). This study compared neurocognitive features associated with model-based and model-free systems in IGD and alcohol use disorder (AUD). Method: Participants diagnosed with IGD (n = 22) and AUD (n = 22), and healthy controls (n = 30) performed the two-stage task inside the functional magnetic resonance imaging (fMRI) scanner. We used computational modeling and hierarchical Bayesian analysis to provide a mechanistic account of their choice behavior. Then, we performed a model-based fMRI analysis and functional connectivity analysis to identify neural correlates of the decision-making processes in each group. Results: The computational modeling results showed similar levels of model-based behavior in the IGD and AUD groups. However, we observed distinct neural correlates of the model-based reward prediction error (RPE) between the two groups. The IGD group exhibited insula-specific activation associated with model-based RPE, while the AUD group showed prefrontal activation, particularly in the orbitofrontal cortex and superior frontal gyrus. Furthermore, individuals with IGD demonstrated hyper-connectivity between the insula and brain regions in the salience network in the context of model-based RPE. Discussion and Conclusions: The findings suggest potential differences in the neurobiological mechanisms underlying model-based behavior in IGD and AUD, albeit shared cognitive features observed in computational modeling analysis. As the first neuroimaging study to compare IGD and AUD in terms of the model-based system, this study provides novel insights into distinct decision-making processes in IGD.

Caffeinated Soda Intake in Children Is Associated with Neurobehavioral Risk Factors for Substance Misuse.

BACKGROUND AND OBJECTIVES: Use of psychotropic substances in childhood has been associated with both impulsivity and other manifestations of poor executive function as well as escalation over time to use of progressively stronger substances. However, how this relationship may start in earlier childhood has not been well explored. Here, we investigated the neurobehavioral correlates of daily caffeinated soda consumption in preadolescent children and examined whether caffeinated soda intake is associated with a higher risk of subsequent alcohol initiation. METHODS: Using Adolescent Brain Cognitive Development study data (N = 2,092), we first investigated cross-sectional relationships between frequent caffeinated soda intake and well-known risk factors of substance misuse: impaired working memory, high impulsivity, and aberrant reward processing. We then examined whether caffeinated soda intake at baseline predicts more alcohol sipping at 12 months follow-up using a machine learning algorithm. RESULTS: Daily consumption of caffeinated soda was cross-sectionally associated with neurobehavioral risk factors for substance misuse such as higher impulsivity scores and lower working memory performance. Furthermore, caffeinated soda intake predicted a 2.04 times greater likelihood of alcohol sipping after 12 months, even after controlling for rates of baseline alcohol sipping rates. CONCLUSIONS: These findings suggest that previous linkages between caffeine and substance use in adolescence also extend to younger initiation, and may stem from core neurocognitive features thought conducive to substance initiation.

Correction: Causal role of the dorsolateral prefrontal cortex in modulating the balance between Pavlovian and instrumental systems in the punishment domain.

[This corrects the article DOI: 10.1371/journal.pone.0286632.].

Complete genome sequence of seed-transmitted soybean yellow mottle mosaic virus from soybeans in Korea.

Soybean yellow mottle mosaic virus (SYMMV), a member of the genus Gammacarmovirus, remains poorly understood in terms of its transmission pathway. This study reveals the complete genome sequence of a seed-transmitted isolate, ST-HB56, contributing to the understanding of SYMMV's ecological dynamics.

Complete genome sequence of soybean geminivirus A in soybean in Korea.

Soybean geminivirus A (SGVA), a member of the family Geminiviridae, was detected in a survey of early-stage soybean. The complete genome sequence of SGVA isolate Habin was determined, revealing its characteristics and similarity to Korean and Chinese isolates. This study contributes to understanding the impact of SGVA on soybean production.

Causal role of the dorsolateral prefrontal cortex in modulating the balance between Pavlovian and instrumental systems in the punishment domain.

Previous literature suggests that a balance between Pavlovian and instrumental decision-making systems is critical for optimal decision-making. Pavlovian bias (i.e., approach toward reward-predictive stimuli and avoid punishment-predictive stimuli) often contrasts with the instrumental response. Although recent neuroimaging studies have identified brain regions that may be related to Pavlovian bias, including the dorsolateral prefrontal cortex (dlPFC), it is unclear whether a causal relationship exists. Therefore, we investigated whether upregulation of the dlPFC using transcranial current direct stimulation (tDCS) would reduce Pavlovian bias. In this double-blind study, participants were assigned to the anodal or the sham group; they received stimulation over the right dlPFC for 3 successive days. On the last day, participants performed a reinforcement learning task known as the orthogonalized go/no-go task; this was used to assess each participant's degree of Pavlovian bias in reward and punishment domains. We used computational modeling and hierarchical Bayesian analysis to estimate model parameters reflecting latent cognitive processes, including Pavlovian bias, go bias, and choice randomness. Several computational models were compared; the model with separate Pavlovian bias parameters for reward and punishment domains demonstrated the best model fit. When using a behavioral index of Pavlovian bias, the anodal group showed significantly lower Pavlovian bias in the punishment domain, but not in the reward domain, compared with the sham group. In addition, computational modeling showed that Pavlovian bias parameter in the punishment domain was lower in the anodal group than in the sham group, which is consistent with the behavioral findings. The anodal group also showed a lower go bias and choice randomness, compared with the sham group. These findings suggest that anodal tDCS may lead to behavioral suppression or change in Pavlovian bias in the punishment domain, which will help to improve comprehension of the causal neural mechanism.

Adaptive Design Optimization as a Promising Tool for Reliable and Efficient Computational Fingerprinting.

A key challenge in understanding mental (dys)functions is their etiological and functional heterogeneity, and several multidimensional assessments have been proposed for their comprehensive characterization. However, such assessments require lengthy testing, which may hinder reliable and efficient characterization of individual differences due to increased fatigue and distraction, especially in clinical populations. Computational modeling may address this challenge as it often provides more reliable measures of latent neurocognitive processes underlying observed behaviors and captures individual differences better than traditional assessments. However, even with a state-of-the-art hierarchical modeling approach, reliable estimation of model parameters still requires a large number of trials. Recent work suggests that Bayesian adaptive design optimization (ADO) is a promising way to address these challenges. With ADO, experimental design is optimized adaptively from trial to trial to extract the maximum amount of information about an individual's characteristics. In this review, we first describe the ADO methodology and then summarize recent work demonstrating that ADO increases the reliability and efficiency of latent neurocognitive measures. We conclude by discussing the challenges and future directions of ADO and proposing development of ADO-based computational fingerprints to reliably and efficiently characterize the heterogeneous profiles of psychiatric disorders.

3D Printing of Skin Equivalents with Hair Follicle Structures and Epidermal-Papillary-Dermal Layers Using Gelatin/Hyaluronic Acid Hydrogels.

Recent advances in three-dimensional (3D) bioprinting technologies have enabled the fabrication of sophisticated live 3D tissue analogs. Despite the existing hydrogel-based bioinks, the development of advanced bioink materials that can accurately reproduce the composition of a native extracellular matrix and mimic the intrinsic properties of laden cells remains challenging. In this study, 3D printed skin equivalents incorporating hair follicle structures and epidermal/papillary dermal layers were fabricated using gelatin methacryloyl/hyaluronic acid methacryloyl (GelMA/HAMA) bioink. The composition of collagen and glycosaminoglycan in native skin was recapitulated by adjusting the combination of GelMA and HAMA. The GelMA/HAMA bioink exhibited excellent viscoelastic and physicochemical properties, 3D printability, cytocompatibility, and functionality to maintain hair-inductive potency while facilitating spontaneous hair pore development. The results indicate that GelMA/HAMA hydrogels are promising candidates as bioinks for the 3D printing of skin equivalents. Furthermore, they may serve as useful models for skin tissue engineering and regeneration.

First report of Tulip Virus X infecting tulip (Tulipa gesneriana) in Korea.

Tulip virus X (tulip virus X, TVX) is a member of the genus Potexvirus (family Alphaflexiviridae) and is a positive single-stranded RNA virus. TVX was described first in Scotland (Mowat 1982), followed by several countries (Yamaji et al. 2001; Tzanetakis et al. 2005; Ward et al. 2008; Dees et al. 2011; Sochacki and Komorowska 2012; Wylie et al. 2019). In April 2021, 86 whole tulip plants showing viral symptoms in leaves (mosaic, yellowing, and malformation) and flowers (color breaking) were collected in Chilgok, Chuncheon, Goseong, Yecheon and Yesan, Korea. Furthermore, high-throughput sequencing was performed to identify viruses that infect tulips in Korea. Total RNA was extracted from pooled the leaves and petals using a Maxwell® 16 LEV Plant RNA Kit (Promega, Madison, USA). We constructed a single library using the TruSeq Stranded Total RNA LT Sample Prep Kit for Plant (Illumina, San Diego, USA). The library was 100 bp paired-end sequenced using Illumina's NovaSeq 6000 (Macrogen, Seoul, Korea) and was assembled de novo using Trinity software version trinityrnaseq_r20140717, with default parameters. The contigs were annotated as in previous study (Lee et al. 2020), revealing a single contig each related to TVX, lily symptomless virus (LSV), and tulip breaking virus (TBV) was generated from 648 million total reads. The TVX-related contig (GenBank ON205948) consisting of 6,076 bp showed 99.52% nucleotide identity (6027/6056 bp) with TVX-J (GenBank AB066288). We conducted an RT-PCR assay to validate the presence of viruses with specific primers as TVX-F5093/R5624 (5'-CTATCCGGACTCATTCTACTTC/GTGCGTTCCAGATAAGCTTG-3'), LSV-F7013/R7338 (5'-CTTGGTCGACAGGGACATAAC/GATTGGAATTGTGCTTTTCAGC-3'), and TBV-F7515/R8116 (5'-GTGTGTCATGGATGATTGTTG/CAACTGATTTGCTACCGCTAG-3'). Consequently, TVX were detected in 13 of 86 samples. Moreover, LSV and TBV were detected in 15 and 26 samples, respectively. However, the yellowing and mosaic observed in the TVX infected samples were not observed in the LSV and TBV infected samples. Subsequently, two TVX amplicons were selected, cloned and sequenced. The obtained sequences were 532 bp and were named YS24 and YS38 (GenBank LC664027 and LC664028), respectively. The Korean isolates showed 98.68% (525/532 bp) and 99.62% (530/532 bp) identity with Australian isolate (GenBank MH886522) in BLASTn analysis. To bioassay for TVX, the infected tulip leaf tissue from which YS24 was obtained was used to sap-inoculate, in triplicates, 15 species of indicator plants (Nicotiana benthamiana, N. clevelandii, N. debneyi, N. glutinosa, N. rustica, N. tabacum, Datura stramonium, Glycine max, Phaseolus vulgaris, Chenopodium amaranticolor, C. quinoa, Cucumis sativus, Cu. melo, Gomphrena globosa, and Tetragonia tetragonioides). After 14 days of inoculation, we observed distinct chlorotic spots on inoculated and upper leaves of C. quinoa, but no symptoms were observed in other indicator plants. In RT-PCR assay using TVX-specific primers, only C. quinoa showed a positive reaction. In previous studies, C. amaranticolor, C. quinoa, G. globosa, and N. benthamiana were known as the experimental host of TVX (Dees et al. 2011; Tzanetakis et al. 2005), but only C. quinoa was confirmed to be susceptible to the Korean isolate. Furthermore, transmission electron microscopy revealed typical flexuous rod-shaped viral particles in the inoculated C. quinoa. To our knowledge, this is the first report of TVX infecting tulips in Korea.

Combinatorial wound healing therapy using adhesive nanofibrous membrane equipped with wearable LED patches for photobiomodulation.

Wound healing is the dynamic tissue regeneration process replacing devitalized and missing tissue layers. With the development of photomedicine techniques in wound healing, safe and noninvasive photobiomodulation therapy is receiving attention. Effective wound management in photobiomodulation is challenged, however, by limited control of the geometrical mismatches on the injured skin surface. Here, adhesive hyaluronic acid-based gelatin nanofibrous membranes integrated with multiple light-emitting diode (LED) arrays are developed as a skin-attachable patch. The nanofibrous wound dressing is expected to mimic the three-dimensional structure of the extracellular matrix, and its adhesiveness allows tight coupling between the wound sites and the flexible LED patch. Experimental results demonstrate that our medical device accelerates the initial wound healing process by the synergetic effects of the wound dressing and LED irradiation. Our proposed technology promises progress for wound healing management and other biomedical applications.

Graphene-Based Nanomaterials for Biomedical Imaging.

Graphene is sp2-hybridized carbon structure-based two-dimensional (2D) sheet. Graphene-based nanomaterials possess several features such as unique mechanical, electronic, thermal, and optical properties, high specific surface area, versatile surface functionalization, and biocompatibility, which attracted researcher's interests in various fields including biomedicine. In this chapter, we particularly focused on the biomedical imaging applications of graphene-based nanomaterials like graphene oxide (GO), reduced graphene oxide (rGO), graphene quantum dots (GQDs), graphene oxide quantum dots (GOQDs), and other derivatives, which utilize their outstanding optical properties. There are some biomedical imaging modalities using Graphene-based Nanomaterials, among which we will highlight fluorescence imaging, Raman imaging, magnetic resonance imaging, and photoacoustic imaging. We also discussed the brief perspectives and future application related to them.

Recent advances in transdermal drug delivery systems: a review.

Various non-invasive administrations have recently emerged as an alternative to conventional needle injections. A transdermal drug delivery system (TDDS) represents the most attractive method among these because of its low rejection rate, excellent ease of administration, and superb convenience and persistence among patients. TDDS could be applicable in not only pharmaceuticals but also in the skin care industry, including cosmetics. Because this method mainly involves local administration, it can prevent local buildup in drug concentration and nonspecific delivery to tissues not targeted by the drug. However, the physicochemical properties of the skin translate to multiple obstacles and restrictions in transdermal delivery, with numerous investigations conducted to overcome these bottlenecks. In this review, we describe the different types of available TDDS methods, along with a critical discussion of the specific advantages and disadvantages, characterization methods, and potential of each method. Progress in research on these alternative methods has established the high efficiency inherent to TDDS, which is expected to find applications in a wide range of fields.

Non-Invasive Topical Drug-Delivery System Using Hyaluronate Nanogels Crosslinked via Click Chemistry.

Hyaluronate (HA) has been widely investigated for noninvasive topical drug delivery of chemical drugs and biopharmaceuticals. However, previous noninvasive delivery systems have been facilitated mostly by chemical conjugation of drugs with HA, which can cause reduced therapeutic efficacy and safety issues in chemically modified drugs. Here, HA nanogels were synthesized by crosslinking via "click" chemistry for noninvasive topical delivery of a model drug without chemical modification. The model-drug-encapsulating HA nanogels could be uptaken to the skin melanoma cells in vitro by HA-mediated endocytosis. In addition, histological analysis showed that HA nanogels could be topically delivered to the deep skin and tongue tissues through the noninvasive delivery routes. Taken together, HA nanogels could be effectively used for the noninvasive topical delivery of various therapeutic drugs.

CRISPR-Cas9 mediated engineering of Bacillus licheniformis for industrial production of (2R,3S)-butanediol.

Bacillus lichenformis is an industrially promising generally recognized as safe (GRAS) strain that can be used for the production of a valuable chemical, 2,3-butanediol (BDO). Conventional gene deletion vectors and/or methods are time-consuming and have poor efficiency. Therefore, clustered regularly interspaced short palindromic repeat (CRISPR)-Cas9 mediated homologous recombination was used to engineer a newly isolated and UV-mutagenized B. licheniformis 4071-15 strain. With the help of a CRISPR-Cas9 system, this one-step process could be used for the deletion of ldh gene within 4 days with high-efficiency exceeding 60%. In addition, the sequential deletion of target genes for engineering studies was evaluated, and it was confirmed that a triple mutant strain (ldh, dgp, and acoR) could be obtained by repeated one-step cycles. Furthermore, a practical metabolic engineering study was carried out using a CRISPR-Cas9 system for the stereospecific production of (2R,3S)-BDO. The predicted (2R,3R)-butanediol dehydrogenase encoded by the gdh gene was selected as a target for the production of (2R,3S)-BDO, and the mutant was successfully obtained. The results show that the stereospecific production of (2R,3S)-BDO was possible with the gdh deletion mutant, while the 4071-15 host strain still generated 26% of (2R,3R)-BDO. It was also shown that the 4071-15 Δgdh mutant could produce 115 g/L of (2R,3S)-BDO in 64 hr by two-stage fed-batch fermentation. This study has shown the efficient development of a (2R,3S)-BDO producing B. licheniformis strain based on CRISPR-Cas9 and fermentation technologies.

In situ immobilized lipase on the surface of intracellular polyhydroxybutyrate granules: preparation, characterization, and its promising use for the synthesis of fatty acid alkyl esters.

Photobacterium lipolyticum M37 lipase (LipM37) was immobilized on the surface of intracellular polyhydroxybutyrate (PHB) granules in Escherichia coli. LipM37 was genetically fused to Cupriavidus necator PHA synthase (PhaC Cn ), and the engineered PHB operon containing the lip M37 -phaC Cn successfully mediated the accumulation of PHB granules (85 wt.%) inside E. coli cells. The PHB granules were isolated from the crude cell extract, and the immobilized LipM37 was comparable with the free form of LipM37 except for a favorable increase in thermostability. The immobilized LipM37 was used to synthesize oleic acid methyl ester (biodiesel) and oleic acid dodecyl ester (wax ester), and yielded 98.0 % conversion in esterification of oleic acid and dodecanol. It was suggested that the LipM37-PhaCCn fusion protein successfully exhibited bifunctional activities in E. coli and that in situ immobilization of lipase to the intracellular PHB could be a promising approach for expanding the biocatalytic toolbox for industrial chemical synthesis.

A New Shuttle Plasmid That Stably Replicates in Clostridium acetobutylicum.

We have developed a new shuttle plasmid, designated as pLK1-MCS that can replicate in both Clostridium acetobutylicum and Escherichia coli, by combining the pUB110 and pUC19 plasmids. Plasmid pLK1-MCS replicated more stably than previously reported plasmids containing either the pIM13 or the pAMß1 replicon in the absence of antibiotic selective pressure. The transfer frequency of pLK1-MCS into C. acetobutylicum was similar to the transfer frequency of other shuttle plasmids. We complemented C. acetobutylicum ML1 (that does not produce solvents such as acetone, butanol, and ethanol owing to loss of the megaplasmid pSOL1 harboring the adhE1-ctfAB-adc operon) by introducing pLK1-MCS carrying the adhE1-ctfAB-adc operon into C. acetobutylicum ML1. The transformed cells were able to resume anaerobic solvent production, indicating that the new shuttle plasmid has the potential for practical use in microbial biotechnology.

Atmospheric vs. anaerobic processing of metabolome samples for the metabolite profiling of a strict anaerobic bacterium, Clostridium acetobutylicum.

Well-established metabolome sample preparation is a prerequisite for reliable metabolomic data. For metabolome sampling of a Gram-positive strict anaerobe, Clostridium acetobutylicum, fast filtration and metabolite extraction with acetonitrile/methanol/water (2:2:1, v/v) at -20°C under anaerobic conditions has been commonly used. This anaerobic metabolite processing method is laborious and time-consuming since it is conducted in an anaerobic chamber. Also, there have not been any systematic method evaluation and development of metabolome sample preparation for strict anaerobes and Gram-positive bacteria. In this study, metabolome sampling and extraction methods were rigorously evaluated and optimized for C. acetobutylicum by using gas chromatography/time-of-flight mass spectrometry-based metabolomics, in which a total of 116 metabolites were identified. When comparing the atmospheric (i.e., in air) and anaerobic (i.e., in an anaerobic chamber) processing of metabolome sample preparation, there was no significant difference in the quality and quantity of the metabolomic data. For metabolite extraction, pure methanol at -20°C was a better solvent than acetonitrile/methanol/water (2:2:1, v/v/v) at -20°C that is frequently used for C. acetobutylicum, and metabolite profiles were significantly different depending on extraction solvents. This is the first evaluation of metabolite sample preparation under aerobic processing conditions for an anaerobe. This method could be applied conveniently, efficiently, and reliably to metabolome analysis for strict anaerobes in air.

Isolation and characterization of a metagenome-derived thermoalkaliphilic esterase with high stability over a broad pH range.

A novel alkaliphilic esterase (EstJ) was identified from a soil metagenome of Jeju Island, Korea, using a 96-well plate-based functional assay for determination of pH dependence of activity. The amino acid sequence of EstJ showed low similarity (32-45 %) to putative α/ß hydrolases derived from whole-genome sequencing studies. EstJ, although not belonging to any of the known families of bacterial lipolytic enzymes, however, it showed closest sequence identity to the family IV enzymes that are related to the mammalian hormone-sensitive lipases. The highly conserved motifs of family IV enzymes were found in EstJ, but the corresponding sequences of each motif in EstJ were unique; most particularly the -(F/Y)(F/Y/L)HGGG- motif was represented by -WMVSGG-. The purified EstJ was highly active from pH 8.5 to 10.5. More than 90 % of maximum activity was also retained over a wide pH range of 5.5-0.5 after prolonged incubation. EstJ was also moderately thermophilic with an optimum temperature of 55 °C. Therefore, EstJ is the first metagenome-derived bacterial family IV esterase possessing both highly alkaliphilic and moderately thermophilic properties.