LiF-Rich Solid Electrolyte Interphase Formation by Establishing Sacrificial Layer on the Separator.

The formation of a stable solid electrolyte interphase (SEI) layer is crucial for enhancing the safety and lifespan of Li metal batteries. Fundamentally, a homogeneous Li+ behavior by controlling the chemical reaction at the anode/electrolyte interface is the key to establishing a stable SEI layer. However, due to the highly reactive nature of Li metal anodes (LMAs), controlling the movement of Li+ at the anode/electrolyte interface remains challenging. Here, an advanced approach is proposed for coating a sacrificial layer called fluorinated self-assembled monolayer (FSL) on a boehmite-coated polyethylene (BPE) separator to form a stable SEI layer. By leveraging the strong affinity between the fluorine functional group and Li+, the rapid formation of a LiF-rich SEI layer in the cell production and early cycling stage is facilitated. This initial stable SEI formation promotes the subsequent homogeneous Li+ flux, thereby improving the LMA stability and yielding an enhanced battery lifespan. Further, the mechanism behind the stable SEI layer generation by controlling the Li+ dynamics through the FSL-treated BPE separator is comprehensively verified. Overall, this research offers significant contributions to the energy storage field by addressing challenges associated with LMAs, thus highlighting the importance of interfacial control in achieving a stable SEI layer.

Surface Oxygen Vacancy Inducing Li-Ion-Conducting Percolation Network in Composite Solid Electrolytes for All-Solid-State Lithium-Metal Batteries.

Composite solid electrolytes (CSEs) are newly emerging components for all-solid-state Li-metal batteries owing to their excellent processability and compatibility with the electrodes. Moreover, the ionic conductivity of the CSEs is one order of magnitude higher than the solid polymer electrolytes (SPEs) by incorporation of inorganic fillers into SPEs. However, their advancement has come to a standstill owing to unclear Li-ion conduction mechanism and pathway. Herein, the dominating effect of the oxygen vacancy (Ovac ) in the inorganic filler on the ionic conductivity of CSEs is demonstrated via Li-ion-conducting percolation network model. Based on density functional theory, indium tin oxide nanoparticles (ITO NPs) are selected as inorganic filler to determine the effect of Ovac on the ionic conductivity of the CSEs. Owing to the fast Li-ion conduction through the Ovac inducing percolation network on ITO NP-polymer interface, LiFePO4 /CSE/Li cells using CSEs exhibit a remarkable capacity in long-term cycling (154 mAh g-1 at 0.5C after 700 cycles). Moreover, by modifying the Ovac concentration of ITO NPs via UV-ozone oxygen-vacancy modification, the ionic conductivity dependence of the CSEs on the surface Ovac from the inorganic filler is directly verified.

Human Pluripotent Stem Cell-Derived Alveolar Organoid with Macrophages.

Alveolar organoids (AOs), derived from human pluripotent stem cells (hPSCs) exhibit lung-specific functions. Therefore, the application of AOs in pulmonary disease modeling is a promising tool for understanding disease pathogenesis. However, the lack of immune cells in organoids limits the use of human AOs as models of inflammatory diseases. In this study, we generated AOs containing a functional macrophage derived from hPSCs based on human fetal lung development using biomimetic strategies. We optimized culture conditions to maintain the iMACs (induced hPSC-derived macrophages) AOs for up to 14 days. In lipopolysaccharide (LPS)-induced inflammatory conditions, IL-1ß, MCP-1 and TNF-α levels were significantly increased in iMAC-AOs, which were not detected in AOs. In addition, chemotactic factor IL-8, which is produced by mononuclear phagocytic cells, was induced by LPS treatment in iMACs-AOs. iMACs-AOs can be used to understand pulmonary infectious diseases and is a useful tool in identifying the mechanism of action of therapeutic drugs in humans. Our study highlights the importance of immune cell presentation in AOs for modeling inflammatory pulmonary diseases.

Time to drink: Activating lateral hypothalamic area neurotensin neurons promotes intake of fluid over food in a time-dependent manner.

The lateral hypothalamic area (LHA) is essential for ingestive behavior but has primarily been studied in modulating feeding, with comparatively scant attention on drinking. This is partly because most LHA neurons simultaneously promote feeding and drinking, suggesting that ingestive behaviors track together. A notable exception are LHA neurons expressing neurotensin (LHANts neurons): activating these neurons promotes water intake but modestly restrains feeding. Here we investigated the connectivity of LHANts neurons, their necessity and sufficiency for drinking and feeding, and how timing and resource availability influence their modulation of these behaviors. LHANts neurons project broadly throughout the brain, including to the lateral preoptic area (LPO), a brain region implicated in modulating drinking behavior. LHANts neurons also receive inputs from brain regions implicated in sensing hydration and energy status. While activation of LHANts neurons is not required to maintain homeostatic water or food intake, it selectively promotes drinking during the light cycle, when ingestive drive is low. Activating LHANts neurons during this period also increases willingness to work for water or palatable fluids, regardless of their caloric content. By contrast, LHANts neuronal activation during the dark cycle does not promote drinking, but suppresses feeding during this time. Finally, we demonstrate that the activation of the LHANts â†’ LPO projection is sufficient to mediate drinking behavior, but does not suppress feeding as observed after generally activating all LHANts neurons. Overall, our work suggests how and when LHANts neurons oppositely modulate ingestive behaviors.

Modeling Hypoxic Stress In Vitro Using Human Embryonic Stem Cells Derived Cardiomyocytes Matured by FGF4 and Ascorbic Acid Treatment.

Mature cardiomyocytes (CMs) obtained from human pluripotent stem cells (hPSCs) have been required for more accurate in vitro modeling of adult-onset cardiac disease and drug discovery. Here, we found that FGF4 and ascorbic acid (AA) induce differentiation of BG01 human embryonic stem cell-cardiogenic mesoderm cells (hESC-CMCs) into mature and ventricular CMs. Co-treatment of BG01 hESC-CMCs with FGF4+AA synergistically induced differentiation into mature and ventricular CMs. FGF4+AA-treated BG01 hESC-CMs robustly released acute myocardial infarction (AMI) biomarkers (cTnI, CK-MB, and myoglobin) into culture medium in response to hypoxic injury. Hypoxia-responsive genes and potential cardiac biomarkers proved in the diagnosis and prognosis of coronary artery diseases were induced in FGF4+AA-treated BG01 hESC-CMs in response to hypoxia based on transcriptome analyses. This study demonstrates that it is feasible to model hypoxic stress in vitro using hESC-CMs matured by soluble factors.

Developing a supervised learning-based social media business sentiment index.

The fast-growing digital data generation leads to the emergence of the era of big data, which become particularly more valuable because approximately 70% of the collected data in the world comes from social media. Thus, the investigation of online social network services is of paramount importance. In this paper, we use the sentiment analysis, which detects attitudes and emotions toward issues of society posted in social media, to understand the actual economic situation. To this end, two steps are suggested. In the first step, after training the sentiment classifiers with several big data sources of social media datasets, we consider three types of feature sets: feature vector, sequence vector and a combination of dictionary-based feature and sequence vectors. Then, the performance of six classifiers is assessed: MaxEnt-L1, C4.5 decision tree, SVM-kernel, Ada-boost, Naïve Bayes and MaxEnt. In the second step, we collect datasets that are relevant to several economic words that the public use to explicitly express their opinions. Finally, we use a vector auto-regression analysis to confirm our hypothesis. The results show the statistically significant relationship between public sentiment and economic performance. That is, "depression" and "unemployment" lead to KOSPI. Also, it shows that the extracted keywords from the sentiment analysis, such as "price," "year-end-tax" and "budget deficit," cause the exchange rates.

Regulating response and leukocyte adhesion of human endothelial cell by gradient nanohole substrate.

Understanding signals in the microenvironment that regulate endothelial cell behavior are important in tissue engineering. Although many studies have examined the cellular effects of nanotopography, no study has investigated the functional regulation of human endothelial cells grown on nano-sized gradient hole substrate. We examined the cellular response of human umbilical vein endothelial cells (HUVECs) by using a gradient nanohole substrate (GHS) with three different types of nanohole patterns (HP): which diameters were described in HP1, 120-200 nm; HP2, 200-280 nm; HP3, 280-360 nm. In results, HP2 GHS increased the attachment and proliferation of HUVECs. Also, gene expression of focal adhesion markers in HUVECs was significantly increased on HP2 GHS. In vitro tube formation assay showed the enhancement of tubular network formation of HUVECs after priming on GHS compared to Flat. Furthermore, leukocyte adhesion was also reduced in the HUVECs in a hole-diameter dependent manner. To summarize, optimal proliferations with reduced leukocyte adhesion of HUVECs were achieved by gradient nanohole substrate with 200-280 nm-sized holes.

Fabrication of Gradient Nanopattern by Thermal Nanoimprinting Technique and Screening of the Response of Human Endothelial Colony-forming Cells.

Nanotopography can be found in various extracellular matrices (ECMs) around the body and is known to have important regulatory actions upon cellular reactions. However, it is difficult to determine the relation between the size of a nanostructure and the responses of cells owing to the lack of proper screening tools. Here, we show the development of reproducible and cost-effective gradient nanopattern plates for the manipulation of cellular responses. Using anodic aluminum oxide (AAO) as a master mold, gradient nanopattern plates with nanopillars of increasing diameter ranges [120-200 nm (GP 120/200), 200-280 nm (GP 200/280), and 280-360 nm (GP 280/360)] were fabricated by a thermal imprinting technique. These gradient nanopattern plates were designed to mimic the various sizes of nanotopography in the ECM and were used to screen the responses of human endothelial colony-forming cells (hECFCs). In this protocol, we describe the step-by-step procedure of fabricating gradient nanopattern plates for cell engineering, techniques of cultivating hECFCs from human peripheral blood, and culturing hECFCs on nanopattern plates.

Manipulation of the response of human endothelial colony-forming cells by focal adhesion assembly using gradient nanopattern plates.

Nanotopography plays a pivotal role in the regulation of cellular responses. Nonetheless, little is known about how the gradient size of nanostructural stimuli alters the responses of endothelial progenitor cells without chemical factors. Herein, the fabrication of gradient nanopattern plates intended to mimic microenvironment nanotopography is described. The gradient nanopattern plates consist of nanopillars of increasing diameter ranges [120-200 nm (GP 120/200), 200-280 nm (GP 200/280), and 280-360 nm (GP 280/360)] that were used to screen the responses of human endothelial colony-forming cells (hECFCs). Nanopillars with a smaller nanopillar diameter caused the cell area and perimeter of hECFCs to decrease and their filopodial outgrowth to increase. The structure of vinculin (a focal adhesion marker in hECFCs) was also modulated by nanostructural stimuli of the gradient nanopattern plates. Moreover, Rho-associated protein kinase (ROCK) gene expression was significantly higher in hECFCs cultured on GP 120/200 than in those on flat plates (no nanopillars), and ROCK suppression impaired the nanostructural-stimuli-induced vinculin assembly. These results suggest that the gradient nanopattern plates generate size-specific nanostructural stimuli suitable for manipulation of the response of hECFCs, in a process dependent on ROCK signaling. This is the first evidence of size-specific nanostructure-sensing behavior of hECFCs. SIGNIFICANCE: Nano feature surfaces are of growing interest as materials for a controlled response of various cells. In this study, we successfully fabricated gradient nanopattern plates to manipulate the response of blood-derived hECFCs without any chemical stimulation. Interestingly, we find that the sensitive nanopillar size for manipulation of hECFCs is range between 120 nm and 200 nm, which decreased the area and increased the filopodial outgrowth of hECFCs. Furthermore, we only modulate the nanopillar size to increase ROCK expression can be an attractive method for modulating the cytoskeletal integrity and focal adhesion of hECFCs.

Nanopillar Surface Topology Promotes Cardiomyocyte Differentiation through Cofilin-Mediated Cytoskeleton Rearrangement.

Nanoscaled surface patterning is an emerging potential method of directing the fate of stem cells. We adopted nanoscaled pillar gradient patterned cell culture plates with three diameter gradients [280-360 (GP 280/360), 200-280 (GP 200/280), and 120-200 nm (GP 120/200)] and investigated their cell fate-modifying effect on multipotent fetal liver kinase 1-positive mesodermal precursor cells (Flk1+ MPCs) derived from embryonic stem cells. We observed increased cell proliferation and colony formation of the Flk1+ MPCs on the nanopattern plates. Interestingly, the 200-280 nm-sized (GP 200/280) pillar surface dramatically increased cardiomyocyte differentiation and expression of the early cardiac marker gene Mesp1. The gradient nanopattern surface-induced cardiomyocytes had cardiac sarcomeres with mature cardiac gene expression. We observed Vinculin and p-Cofilin-mediated cytoskeleton reorganization during this process. In summary, the gradient nanopattern surface with 200-280 nm-sized pillars enhanced cardiomyocyte differentiation in Flk1+ MPCs.

Intrinsic FGF2 and FGF5 promotes angiogenesis of human aortic endothelial cells in 3D microfluidic angiogenesis system.

The human body contains different endothelial cell types and differences in their angiogenic potential are poorly understood. We compared the functional angiogenic ability of human aortic endothelial cells (HAECs) and human umbilical vein endothelial cells (HUVECs) using a three-dimensional (3D) microfluidic cell culture system. HAECs and HUVECs exhibited similar cellular characteristics in a 2D culture system; however, in the 3D microfluidic angiogenesis system, HAECs exhibited stronger angiogenic potential than HUVECs. Interestingly, the expression level of fibroblast growth factor (FGF)2 and FGF5 under vascular endothelial growth factor (VEGF)-A stimulation was significantly higher in HAECs than in HUVECs. Moreover, small interfering RNA-mediated knockdown of FGF2 and FGF5 more significantly attenuated vascular sprouting induced from HAECs than HUVECs. Our results suggest that HAECs have greater angiogenic potential through FGF2 and FGF5 upregulation and could be a compatible endothelial cell type to achieve robust angiogenesis.

Human endothelial colony forming cells from adult peripheral blood have enhanced sprouting angiogenic potential through up-regulating VEGFR2 signaling.

BACKGROUND: Endothelial colony forming cells (ECFCs), a subtype of endothelial progenitor cells, have been studied as a promising cellular source for therapeutic angiogenesis. Although ECFCs are very similar to mature endothelial cells, details regarding the role of ECFCs during angiogenesis are not known. We compared the cellular and angiogenic properties of ECFCs and mature endothelial cells (HUVECs). METHODS: HUVECs were used as control. Quantitative RT-PCR, western blotting, immunofluorescence staining, flow cytometric analyses and angiogenic cytokine array were performed. 3D-microfluidic angiogenesis assay system was adopted for in vitro angiogenic potential. In vivo angiogenic potential was assessed by Matrigel plug assay. RESULTS: ECFCs had higher expression of activated endothelial tip cell markers (Dll4, CXCR4, CD34, and VCAM1) and arterial genes (DLL4 and CX40), but lower expression of venous and lymphatic genes (COUP-TFII and PROX1). In 3D-microfluidic angiogenesis assay system, ECFCs induced robust sprouting vascular structures. Co-cultivation of both ECFCs and HUVECs gave rise to lumen-formed hybrid vascular structures, with the resulting ECFCs predominantly localized to the tip portion. This finding suggests that the ECFC has a role as a sprouting endothelial tip cell. Interestingly, VEGF-A phosphorylated VEGFR2 and its downstream signaling molecules more strongly in ECFCs than in HUVECs. Even small amount of VEGF-A successfully induced the sprouting angiogenesis of ECFCs. Finally, co-administration of ECFCs and human dermal fibroblasts successfully induced lumen-formed maturated neovessels in vivo. CONCLUSION: ECFCs derived from adult peripheral blood had enhanced sprouting angiogenic potential in vitro and in vivo through up-regulation of the VEGFR2 signaling pathway.

Mixl1 and Flk1 Are Key Players of Wnt/TGF-ß Signaling During DMSO-Induced Mesodermal Specification in P19 cells.

Dimethyl sulfoxide (DMSO) is widely used to induce multilineage differentiation of embryonic and adult progenitor cells. To date, little is known about the mechanisms underlying DMSO-induced mesodermal specification. In this study, we investigated the signaling pathways and lineage-determining genes involved in DMSO-induced mesodermal specification in P19 cells. Wnt/ß-catenin and TGF-ß superfamily signaling pathways such as BMP, TGF-ß and GDF1 signaling were significantly activated during DMSO-induced mesodermal specification. In contrast, Nodal/Cripto signaling pathway molecules, required for endoderm specification, were severely downregulated. DMSO significantly upregulated the expression of cardiac mesoderm markers but inhibited the expression of endodermal and hematopoietic lineage markers. Among the DMSO-activated cell lineage markers, the expression of Mixl1 and Flk1 was dramatically upregulated at both the transcript and protein levels, and the populations of Mixl1+, Flk1+ and Mixl1+/Flk1+ cells also increased significantly. DMSO modulated cell cycle molecules and induced cell apoptosis, resulting in significant cell death during EB formation of P19 cells. An inhibitor of Flk1, SU5416 significantly blocked expressions of TGF-ß superfamily members, mesodermal cell lineage markers and cell cycle molecules but it did not affect Wnt molecules. These results demonstrate that Mixl1 and Flk1 play roles as key downstream or interacting effectors of Wnt/TGF-ß signaling pathway during DMSO-induced mesodermal specification in P19 cells.

Smooth muscle progenitor cells from peripheral blood promote the neovascularization of endothelial colony-forming cells.

Proangiogenic cell therapy using autologous progenitors is a promising strategy for treating ischemic disease. Considering that neovascularization is a harmonized cellular process that involves both endothelial cells and vascular smooth muscle cells, peripheral blood-originating endothelial colony-forming cells (ECFCs) and smooth muscle progenitor cells (SMPCs), which are similar to mature endothelial cells and vascular smooth muscle cells, could be attractive cellular candidates to achieve therapeutic neovascularization. We successfully induced populations of two different vascular progenitor cells (ECFCs and SMPCs) from adult peripheral blood. Both progenitor cell types expressed endothelial-specific or smooth muscle-specific genes and markers, respectively. In a protein array focused on angiogenic cytokines, SMPCs demonstrated significantly higher expression of bFGF, EGF, TIMP2, ENA78, and TIMP1 compared to ECFCs. Conditioned medium from SMPCs and co-culture with SMPCs revealed that SMPCs promoted cell proliferation, migration, and the in vitro angiogenesis of ECFCs. Finally, co-transplantation of ECFCs and SMPCs induced robust in vivo neovascularization, as well as improved blood perfusion and tissue repair, in a mouse ischemic hindlimb model. Taken together, we have provided the first evidence of a cell therapy strategy for therapeutic neovascularization using two different types of autologous progenitors (ECFCs and SMPCs) derived from adult peripheral blood.

Cardiomyocyte specific deletion of Crif1 causes mitochondrial cardiomyopathy in mice.

Mitochondria are key organelles dedicated to energy production. Crif1, which interacts with the large subunit of the mitochondrial ribosome, is indispensable for the mitochondrial translation and membrane insertion of respiratory subunits. To explore the physiological function of Crif1 in the heart, Crif1(f/f) mice were crossed with Myh6-cre/Esr1 transgenic mice, which harbor cardiomyocyte-specific Cre activity in a tamoxifen-dependent manner. The tamoxifen injections were given at six weeks postnatal, and the mutant mice survived only five months due to hypertrophic heart failure. In the mutant cardiac muscles, mitochondrial mass dramatically increased, while the inner structure was altered with lack of cristae. Mutant cardiac muscles showed decreased rates of oxygen consumption and ATP production, suggesting that Crif1 plays a critical role in the maintenance of both mitochondrial structure and respiration in cardiac muscles.