RESUMO
Primary immune thrombocytopenia (ITP) is an acquired autoimmune hemorrhagic disease. Loss of immune tolerance plays a crucial role in the pathogenesis of ITP. Monocytes and macrophages play an indispensable role in the pathophysiology of hematopoietic malignancies and have been implicated as key players in platelet destruction. Approximately 80% of adult patients with ITP exhibit corticosteroid treatment failure or become dependent, requiring novel therapy. Thrombopoietin (TPO) receptor agonists (TPO-RAs) have been used clinically to manage ITP effectively, however, little is known about the effect of TPO-RAs on monocyte and macrophage modulation in adult ITP. In this study, we investigated the phenotypic evolution and potential immunomodulatory roles of monocytes/macrophages in ITP patients receiving eltrombopag therapy. Results showed that the peripheral monocyte count positively correlated with IFN-γ/IL-4 ratio in ITP patients. Moreover, numerous phenotype-associated genes in ITP macrophages exhibited diverse responses, and ITP macrophages exhibited more M1-related characteristics. After eltrombopag therapy, the peripheral monocyte count and IFN-γ/IL-4 ratio significantly decreased in ITP patients. M1-related characteristics of ITP macrophages were partially reversed by eltrombopag. Therefore, this study revealed eltrombopag restored the monocyte dynamics and the associated Th1/Th2 imbalance, and partially reversed the M1-related characteristics of the ITP macrophages, which suggest the potential vital roles of TPO-RAs in regulating the monocyte/macrophage plasticity in ITP.
What is the context? Primary immune thrombocytopenia (ITP) is an acquired autoimmune hemorrhagic disease. Loss of immune tolerance plays a crucial role in the pathogenesis of ITP.Monocytes and macrophages play an indispensable role in the pathophysiology of hematopoietic malignancies and have been implicated as key players in platelet destruction.Approximately 80% of adult patients with ITP exhibit corticosteroid treatment failure or become dependent, requiring novel therapy. Thrombopoietin (TPO) receptor agonists (TPO-RAs) have been used clinically to manage ITP effectively, however, little is known about the effect of TPO-RAs on monocyte and macrophage modulation in ITP.What is new?In this study, we investigated the phenotypic evolution and potential immunomodula-tory roles of monocytes/macrophages in ITP patients receiving eltrombopag therapy.The expansion of peripheral monocytes positively correlated with IFN-γ/IL-4 ratio in ITP patients.ITP macrophages exhibited more M1-related characteristics.After eltrombopag therapy, the peripheral monocyte count and IFN-γ/IL-4 ratio significantly decreased in ITP patients.M1-related characteristics of ITP macrophages were partially reversed by eltrombopag.What is the impact?This study provides evidence that the potential vital roles of TPO-RAs in regulating the monocyte/macrophage plasticity in ITP.
Assuntos
Púrpura Trombocitopênica Idiopática , Trombocitopenia , Humanos , Púrpura Trombocitopênica Idiopática/tratamento farmacológico , Monócitos , Receptores de Trombopoetina/agonistas , Interleucina-4 , Hidrazinas/farmacologia , Hidrazinas/uso terapêutico , Benzoatos/farmacologia , Benzoatos/uso terapêutico , Trombopoetina , Trombocitopenia/induzido quimicamente , Fenótipo , Macrófagos , Proteínas Recombinantes de FusãoRESUMO
Recognition of structure prototypes from tremendous known inorganic crystal structures has been an important subject beneficial for materials science research and new materials design. The existing databases of inorganic crystal structure prototypes were mostly constructed by classifying materials in terms of the crystallographic space group information. Herein, we employed a distinct strategy to construct the inorganic crystal structure prototype database, relying on the classification of materials in terms of local atomic environments (LAEs) accompanied by unsupervised machine learning method. Specifically, we adopted a hierarchical clustering approach onto all experimentally known inorganic crystal structure data to identify structure prototypes. The criterion for hierarchical clustering is the LAE represented by the state-of-the-art structure fingerprints of the improved bond-orientational order parameters and the smooth overlap of atomic positions. This allows us to build up a LAE-based Inorganic Crystal Structure Prototype Database (LAE-ICSPD) containing 15,613 structure prototypes with defined stoichiometries. In addition, we have developed a Structure Prototype Generator Infrastructure (SPGI) package, which is a useful toolkit for structure prototype generation. Our developed SPGI toolkit and LAE-ICSPD are beneficial for investigating inorganic materials in a global way as well as accelerating the materials discovery process in the data-driven mode.
RESUMO
In this work, the electrical conductivity and optical transparency of the In-Sn-Zn-O (ITZO) films annealed at different temperatures were investigated. The results show that the ITZO films transformed from amorphous phase to crystalline phase after annealed in the air. The transmittance of the films improves significantly and all exceed 88%. Meanwhile, the annealed ITZO films exhibit a significant enhancement in conductivity. In particular, ITZO film annealed at 650 °C has high electrical conductivity (â¼4.94 × 102S cm-1) and an excellent figure of merit (â¼5.94 × 10-4Ω-1). Moreover, ITZO thin film transistors were prepared and their performance was tested. After annealing, the high electrical properties of the active layer make the gate regulation ability of the thin film transistors degrade. The annealed films with excellent optoelectronic properties can be applied to transparent electrodes.
RESUMO
p-type CuI films with optimized optoelectronic performance were synthesized by solid-phase iodination of Cu3N precursor films at room temperature. The effects of the deposition power of Cu3N precursors on the structural, electrical, and optical properties of the CuI films were systematically investigated. X-ray diffraction results show that all the CuI films possess a zinc-blende structure. When the deposition power of Cu3N precursors was 140 W, the CuI films present a high transmittance above 84% in the visible region, due to their smaller root-mean-square roughness values of 9.23 nm. Moreover, these films also have a low resistivity of 1.63 × 10-2Ω·cm and a boosted figure of merit of 140.7 MΩ-1. These results are significant achievements among various p-types TCOs, confirming the promising prospects of CuI as a p-type transparent semiconductor applied in transparent electronics.
RESUMO
BACKGROUND: Postmenopausal osteoporosis is a common bone disease and characterized by low bone mineral density. AIM: This study aimed to reveal key genes associated with postmenopausal osteoporosis (PMO), and provide a theoretical basis for subsequent experiments. METHODS: The dataset GSE7429 was obtained from Gene Expression Omnibus. A total of 20 B cell samples (ten ones, respectively from postmenopausal women with low or high bone mineral density (BMD) were included in this dataset. Following screening of differentially expressed genes (DEGs), coexpression analysis of all genes was performed, and key genes in the coexpression network were screened using the random walk algorithm. Afterwards, functional and pathway analyses were conducted. Additionally, protein-protein interactions (PPIs) between DEGs and key genes were analyzed. RESULTS: A set of 308 DEGs (170 up-regulated ones and 138 down-regulated ones) between low BMD and high BMD samples were identified, and 101 key genes in the coexpression network were screened out. In the coexpression network, some genes had a higher score and degree, such as CSTA. The key genes in the coexpression network were mainly enriched in GO terms of the defense response (e.g., SERPINA1 and CST3), immune response (e.g., IL32 and CLEC7A); while, the DEGs were mainly enriched in structural constituent of cytoskeleton (e.g., CYLC2 and TUBA1B) and membrane-enclosed lumen (e.g., CCNE1 and INTS5). In the PPI network, CCNE1 interacted with REL; and TUBA1B interacted with ESR1. CONCLUSIONS: A series of interactions, such as CSTA/TYROBP, CCNE1/REL and TUBA1B/ESR1 might play pivotal roles in the occurrence and development of PMO.
Assuntos
Densidade Óssea , Osteoporose Pós-Menopausa , Idoso , Regulação para Baixo , Feminino , Expressão Gênica , Perfilação da Expressão Gênica/métodos , Predisposição Genética para Doença , Humanos , Pessoa de Meia-Idade , Osteoporose Pós-Menopausa/diagnóstico , Osteoporose Pós-Menopausa/genética , Osteoporose Pós-Menopausa/fisiopatologia , Mapas de Interação de Proteínas , Regulação para CimaRESUMO
Autosomal Recurrent Primary Microscopic (MCPH, OMIM: 251200) is a neurodevelopmental disorder that is characterized by a noticeable decrease in brain size, particularly in the cerebral cortex, but with a normal brain structure and a non-progressive intellectual disability. MCPH1 has been identified as the gene that triggers primary microcephaly (MCPH1ï¼OMIM: 607117). Here we report a case of autosomal recessive primary microcephaly as caused by a novel variant in the MCPH1 gene. Head circumference was measured by Magnetic Resonance Imaging (MRI), while the Wechsler Intelligence Scale was used to evaluate the intelligence of the individual being tested. B-ultrasound was used to assess gonadal development, and semen routine was used to assess sperm status. The whole-exome sequencing (WES) was performed on the proband. Sanger sequencing was conducted on the parents of the proband to determine if the novel variant in the MCPH1 gene was present. The effect of the mutation on the splicing of MCPH1 was verified by minigene approach. It was observed that the proband had autosomal recessive primary microcephaly and azoospermatism. A novel splice-site homozygous mutation (c.233+2T > G) of the MCPH1 gene was identified, which inherited from his parents. Minigene approach confirmed that c.233+2T > G could affect the splicing of MCPH1. Therefore, our findings contributed to the mutation spectrum of the MCPH1 gene and may be useful in the diagnosis and gene therapy of MCPH.
RESUMO
Systemic iron overload is a common clinical challenge leading to significantly serious complications in patients with acute myeloid leukemia (AML), which affects both the quality of life and the overall survival of patients. Symptoms can be relieved after iron chelation therapy in clinical practice. However, the roles and mechanisms of iron overload on the initiation and progression of leukemia remain elusive. Here we studied the correlation between iron overload and AML clinical outcome, and further explored the role and pathophysiologic mechanism of iron overload in AML by using two mouse models: an iron overload MLL-AF9-induced AML mouse model and a nude xenograft mouse model. Patients with AML had an increased ferritin level, particularly in the myelomonocytic (M4) or monocytic (M5) subtypes. High level of iron expression correlated with a worsened prognosis in AML patients and a shortened survival time in AML mice. Furthermore, iron overload increased the tumor load in the bone marrow (BM) and extramedullary tissues by promoting the proliferation of leukemia cells through the upregulation of FOS. Collectively, our findings provide new insights into the roles of iron overload in AML. Additionally, this study may provide a potential therapeutic target to improve the outcome of AML patients and a rationale for the prospective evaluation of iron chelation therapy in AML.
Assuntos
Sobrecarga de Ferro , Leucemia Mieloide Aguda , Humanos , Animais , Camundongos , Regulação para Cima , Qualidade de Vida , Leucemia Mieloide Aguda/genética , Ferro/metabolismo , Proteína de Leucina Linfoide-Mieloide/genética , Proteína de Leucina Linfoide-Mieloide/metabolismo , Proteínas de Fusão Oncogênica/genéticaRESUMO
Organic light-emitting diodes (OLEDs) exploiting simple binary emissive layers (EMLs) blending only emitters and hosts have natural advantages in low-cost commercialization. However, previously reported OLEDs based on binary EMLs hardly simultaneously achieved desired comprehensive performances, e.g., high efficiency, low efficiency roll-off, narrow emission bands, and high operation stability. Here, we report a molecular-design strategy. Such a strategy leads to a fast reverse intersystem crossing rate in our designed emitter h-BNCO-1 of 1.79×105 s-1. An OLED exploiting a binary EML with h-BNCO-1 achieves ultrapure emission, a maximum external quantum efficiency of over 40% and a mild roll-off of 14% at 1000 cd·m-2. Moreover, h-BNCO-1 also exhibits promising operational stability in an alternative OLED exploiting a compact binary EML (the lifetime reaching 95% of the initial luminance at 1000 cd m-2 is ~ 137 h). Here, our work has thus provided a molecular-design strategy for OLEDs with promising comprehensive performance.
RESUMO
We describe our experience with a two-incision anterolateral acromial approach in locking plate fixation of proximal humeral fractures in older adults. Mean time between injury and surgery was 3.08 +/- 1.24 days. A proximal anterolateral transverse incision and a more distal longitudinal incision were used. A locking plate was inserted along the lateral side of the humerus from the proximal incision to the distal fragment of the humerus. Mean operation time was 62.37 +/- 19.05 minutes. There were no instances of axillary nerve paralysis or infection. Postoperative imaging results were satisfactory in all cases. Three obese patients experienced fat liquefaction at the incision site. Mean total Neer score one year after surgery was 88.16 +/- 5.05. We conclude that the two-incision anterolateral acromial approach with use of locking plates appears to be an effective means to treat proximal humeral fractures in older adults.
Assuntos
Fixação Interna de Fraturas/métodos , Fraturas do Ombro/cirurgia , Acidentes por Quedas/estatística & dados numéricos , Acidentes de Trânsito/estatística & dados numéricos , Idoso , Placas Ósseas , Parafusos Ósseos , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Estudos RetrospectivosRESUMO
Background: The most common disease caused by biallelic AFG3L2 mutations is spastic ataxia type 5 (SPAX5). Identification of complex phenotypes resulting from biallelic AFG3L2 mutations has been increasing in recent years. Methods: A retrospective analysis was performed on a child with microcephaly and recurrent seizures. The child underwent physical and neurological examinations, laboratory tests, electroencephalography (EEG), and brain magnetic resonance imaging (MRI). Trio-whole-exome sequencing (trio-WES) was performed to identify possible causative mutations. Results: We described a child who exhibited early-onset and intractable epilepsy, developmental regression, microcephaly, and premature death. Neuroimaging revealed global cerebral atrophy (GCA) involving the cerebrum, cerebellum, corpus callosum, brainstem, cerebellar vermis, and basal ganglia. On trio-WES, two novel compound heterozygous mutations, c.1834G > T (p.E612*) and c.2176-6T > A in the AFG3L2 gene, were identified in this patient. Conclusions: Our findings have expanded the mutation spectrum of the AFG3L2 gene and identified a severe neurodegenerative phenotype of global cerebral atrophy caused by biallelic AFG3L2 mutations.
RESUMO
Poly(ether-ether-ketone) (PEEK) with good biocompatibility exhibits high mechanical strengths but bioinert. In addition, tantalum (Ta) possesses outstanding osteogenesis but high density and elastic modulus, and cost. In this study, by blending Ta nanoparticles with PEEK, Ta/PEEK composite (TP) was prepared, which was then treated by concentrated sulfuric acid to form a microporous surface containing Ta particles on TP (TPS). Moreover, genistein (GS) with antibacterial property was loaded into the microporous surface of TPS (TPSG). Compared with TP, the surface properties (e.g., surface roughness and hydrophilicity) of TPS was obviously improved because of the microporous surface including Ta nanoparticles. Moreover, TPS showed low antibacterial properties because of presence of sulfonic group while TPSG exhibited excellent antibacterial properties due to GS loaded into the microporous surface. Furthermore, compared with TP, TPS obviously promoted attachment and proliferation of MG63 cells, while TPSG with GS remarkably inducing osteogenic differentiation of the cells compared with TPS in vitro. Moreover, in comparison with TP, TPS with optimized surface properties promoted new bone regeneration and osseointegration, while TPSG loading GS further enhanced bone regeneration as well as osseointegration in vivo. In summary, the GS loaded into microporous surface including Ta nanoparticles of TPSG exhibited antibacterial and osteogenic activity, which would have great potential for bone tissue repair.
Assuntos
Osseointegração , Tantálio , Antibacterianos/farmacologia , Benzofenonas , Genisteína , Osteogênese , PolímerosRESUMO
Osteoarthritis (OA) is characterized by cartilage matrix degeneration and chondrocyte apoptosis. Prolonged endoplasmic reticulum (ER) stress participates in chondrocyte apoptosis and cartilage degeneration in OA progression. miR-486-5p could suppress the apoptosis of nucleus pulposus cells and cardiomyocyte, yet whether miR-486-5p modified exosomes could modulate ER stress and apoptosis of chondrocytes remain unknown. We validated the increased inflammation and ER stress in OA synovium and cartilage, and the inhibition of ER stress could attenuate the IL-1ß induced chondrocyte apoptosis. Administration of exogenous miR-486-5p could inhibit the ER stress, alleviate chondrocytes apoptosis and promote matrix regeneration. In comparison with direct administration of miR-486-5p and miR-486-5p overexpressing ADSCs, miR-486-5p modified exosomes indicated a better effect in modulating chondrocyte homeostasis. MiR-486-5p containing exosomes could also regulate macrophage polarization. Our IVIS imaging data validated that intraarticular injection of miR-486-5p containing exosomes could sustain for at least 7 days. MiR-486-5p containing exosomes showed a better effect on alleviating rats OA compared with direct administration of miR-486-5p and miR-486-5p overexpressing ADSCs. Our data demonstrated that miR-486-5p modified exosomes have a better effect on alleviating chondrocyte apoptosis and osteoarthritis. This study provides evidence of this efficient strategy of exosomal miRNA delivery and the miRNA-based therapy for OA.
Assuntos
Exossomos , MicroRNAs , Osteoartrite , Ratos , Animais , Condrócitos , Exossomos/genética , Estresse do Retículo Endoplasmático , Osteoartrite/genética , Osteoartrite/terapia , Apoptose , MicroRNAs/genética , MicroRNAs/farmacologiaRESUMO
OBJECTIVES: To explore the application of third-generation sequencing (TGS) for genetic diagnosis and prenatal genetic screening of thalassemia genes. METHODS: Two groups of subjects were enrolled in this study. The first group included 176 subjects with positive hematological phenotypes for thalassemia. Thalassemia-associated genes were detected simultaneously in each sample using both the PacBio TGS platform based on single-molecule real-time (SMRT) technology and the conventional PCR-reverse dot blot (PCR-RDB). Sanger sequencing was used for validation when results were discordant between the two methods. The second group included 53 couples with at least one partner having a positive thalassemia hematological phenotype, and they were screened for homotypic thalassemia variants by TGS, and the risk of pregnancies with babies presenting with severe thalassemia, was assessed. RESULTS: Of the 176 subjects, 175 had concordant genotypes between the two methods, including 63 normal subjects and 112 α- and/or ß-thalassemia gene carriers, with a concordance rate of 99.43%. TGS detected a rare ß-thalassemia gene variant -50 (G > A) that was not detected by conventional PCR-RDB. TGS identified seven of the 53 couples as homotypic thalassemia gene carriers, five of whom were at risk of pregnancies with severe thalassemia. CONCLUSION: TGS could effectively detect common and rare thalassemia variants with high accuracy and efficiency. This approach would be suitable for prenatal thalassemia genetic screening in areas with high incidence of thalassemia.
Assuntos
Talassemia alfa , Talassemia beta , Gravidez , Feminino , Humanos , Talassemia beta/diagnóstico , Talassemia beta/epidemiologia , Talassemia beta/genética , Talassemia alfa/diagnóstico , Talassemia alfa/epidemiologia , Talassemia alfa/genética , Testes Genéticos , China/epidemiologia , Diagnóstico Pré-Natal/métodos , Genótipo , MutaçãoRESUMO
Lead halide perovskites have emerged in the last decade as advantageous high-performance optoelectronic semiconductors, and have undergone rapid development for diverse applications such as solar cells, light-emitting diodes , and photodetectors. While material instability and lead toxicity are still major concerns hindering their commercialization, they offer promising prospects and design principles for developing promising optoelectronic materials. The distinguished optoelectronic properties of lead halide perovskites stem from the Pb2+ cation with a lone-pair 6s2 electronic configuration embedded in a mixed covalent-ionic bonding lattice. Herein, we summarize alternative Pb-free semiconductors containing lone-pair ns2 cations, intending to offer insights for developing potential optoelectronic materials other than lead halide perovskites. We start with the physical underpinning of how the ns2 cations within the material lattice allow for superior optoelectronic properties. We then review the emerging Pb-free semiconductors containing ns2 cations in terms of structural dimensionality, which is crucial for optoelectronic performance. For each category of materials, the research progresses on crystal structures, electronic/optical properties, device applications, and recent efforts for performance enhancements are overviewed. Finally, the issues hindering the further developments of studied materials are surveyed along with possible strategies to overcome them, which also provides an outlook on the future research in this field.
RESUMO
Antioxidants can protect organization from damage by scavenging of free radicals. When two kinds of antioxidants are consumed together, the total antioxidant capacity might be enhanced via synergistic interactions. Herein, we develop a simple, direct, and effective strategy to quantify the synergistic interaction between ascorbic acid (AA) and other different antioxidants by photoelectrochemical (PEC) technology. MXene Ti3C2-TiO2 composites fabricated via hydrogen peroxide oxidation were applied as sensing material for the antioxidants interaction study. Under excitation of 470 nm wavelength, the photogenerated electrons transfer from the conduction band of TiO2 nanoparticles to the Ti3C2 layers, and the holes in TiO2 can oxidize antioxidants, leading to an enhanced photocurrent as the detection signal. This PEC sensor exhibits a good linear range to AA concentrations from 12.48 to 521.33 µM as well as obvious antioxidants capability synergism. In particular, the photocurrents of AA + gallic acid (GA) and AA + chlorogenic acid (CHA) mixtures at 476.19 µM increase 1.95 and 2.35 times respectively comparing with the sum of photocurrents of AA and GA or CHA. It is found that the synergistic effect is mainly depending on the fact that AA with the low redox potential (0.246 V vs NHE) can reduce other antioxidants radical to promote regeneration, improving the overall antioxidant performance. Moreover, it is proved that the greater redox potential of antioxidants, the more obvious the synergistic effect. In addition, the sensor was used to real sample assay, which provides available information towards food nutrition analysis, health products design and quality inspection.
Assuntos
Antioxidantes , Técnicas Biossensoriais , Ácido Ascórbico , Técnicas Eletroquímicas , Oxirredução , TitânioRESUMO
Materials informatics has emerged as a promisingly new paradigm for accelerating materials discovery and design. It exploits the intelligent power of machine learning methods in massive materials data from experiments or simulations to seek new materials, functionality, and principles, etc. Developing specialized facilities to generate, collect, manage, learn, and mine large-scale materials data is crucial to materials informatics. We herein developed an artificial-intelligence-aided data-driven infrastructure named Jilin Artificial-intelligence aided Materials-design Integrated Package (JAMIP), which is an open-source Python framework to meet the research requirements of computational materials informatics. It is integrated by materials production factory, high-throughput first-principles calculations engine, automatic tasks submission and monitoring progress, data extraction, management and storage system, and artificial intelligence machine learning based data mining functions. We have integrated specific features such as an inorganic crystal structure prototype database to facilitate high-throughput calculations and essential modules associated with machine learning studies of functional materials. We demonstrated how our developed code is useful in exploring materials informatics of optoelectronic semiconductors by taking halide perovskites as typical case. By obeying the principles of automation, extensibility, reliability, and intelligence, the JAMIP code is a promisingly powerful tool contributing to the fast-growing field of computational materials informatics.
Assuntos
Inteligência Artificial , Informática , Reprodutibilidade dos Testes , Aprendizado de Máquina , InteligênciaRESUMO
One-dimensional semiconductor nanostructures have already been used for a variety of optoelectronic applications. Metal halide perovskites have emerged in recent years as promising high-performance optoelectronic materials, but reports on 1D nanorods (NRs) of all-inorganic halide perovskites are still scarce. This work demonstrates a synthetic strategy toward cesium-based inorganic perovskite NRs by exploiting composition-controlled crystal phase engineering. It is accomplished for Cd-rich mixed-cation CsPb1- x Cd x Br3 nanocrystals, where the initial 1D hexagonal perovskite phase drives the growth of the 1D NRs, as supported by first-principles calculations. The band gaps of the resulting NRs are tunable by varying the Cd-content, and the highly uniform CsPb0.08Cd0.92Br3 NRs (with an average length of 84 nm and width of 16 nm) exhibit a true blue-color emission centered at 460 nm, with a high quantum yield of 48%. Moreover, this work also demonstrates the tunability of the Fermi levels in the films made of CsPb1- x Cd x Br3 alloyed nanocrystals, where samples with highest Cd content show an increase of the electron concentration and a related increase in the conductivity.
RESUMO
All-inorganic halide perovskites are promising materials for optoelectronic applications. The surface or interface structure of the perovskites plays a crucial role in determining the optoelectronic conversion efficiency, as well as the material stability. A thorough understanding of surface atomic structures of the inorganic perovskites and their contributions to their optoelectronic properties and stability is lacking. Here we show a scanning tunneling microscopy investigation on the atomic and electronic structure of CsPbBr3 perovskite. Two different surface structures with a stripe and an armchair domain are identified, which originates from a complex interplay between Cs cations and Br anions. Our findings are further supported and correlated with density functional theory calculations and photoemission spectroscopy measurements. The stability evaluation of photovoltaic devices indicates a higher stability for CsPbBr3 in comparison with MAPbBr3, which is closely related to the low volatility of Cs from the perovskite surface.
RESUMO
Adipose-derived stem cells (ADSCs) hold great potential in cartilage tissue engineering due to their multipotency and ease of availability. MRI is an effective and noninvasive imaging approach to track cells and observe new tissue regeneration. It is essential to find a compatible and efficient imaging reagent without affecting the stemness of ADSCs. Herein, we developed chitosan-modified iron oxide nanoparticles (IO-CS) as the T 2 contrast reagent with good cell compatibility and high cellular uptake efficiency and used IO-CS for ADSC intra-articular imaging in a rat osteoarthritis (OA) model. TEM demonstrated the great morphology and size distribution of IO-CS nanoparticles with the size of 17 nm. Magnetization (29.4 emu per g) and MRI tests confirmed (R 2 of 184 mM-1 s-1) the feasibility of IO-CS nanoparticles as an MRI contrast reagent. In addition, the IO-CS nanoparticles showed good cellular compatibility and high labeling efficiency as compared to the commercial agent ferumoxytol. Moreover, incorporation of IO-CS nanoparticles did not alter the adipogenic, osteogenic and chondrogenic differentiation ability of ADSCs. Furthermore, the MRI transverse R 2 maps showed a persistence time of the IO-CS nanoparticles in ADSCs of 6 days in vitro. Then, we investigated the imaging capability of the IO-CS nanoparticle-labeled ADSCs in vivo with MRI for 5 weeks. The histological studies demonstrated the intra-articular biodistribution of the IO-CS nanoparticles, including in the cartilage superficial layer, synovial sublining layer, periosteum and bone marrow cavity. They provided systemic distribution information of the ADSCs in the OA rat model. In summary, we developed an accessible and effective T 2 imaging reagent with good biocompatibility and maintenance of the stemness of ADSCs. This showed the potential translational application of IO-CS nanoparticles as an MRI reagent in cartilage tissue engineering.
RESUMO
Atomically thin, two-dimensional (2D) indium selenide (InSe) has attracted considerable attention due to the large tunability in the band gap (from 1.4 to 2.6 eV) and high carrier mobility. The intriguingly high dependence of the band gap on layer thickness may lead to novel device applications, although its origin remains poorly understood, and is generally attributed to the quantum confinement effect. In this work, we demonstrate via first-principles calculations that strong interlayer coupling may be mainly responsible for this phenomenon, especially in the fewer-layer region, and it could also be an essential factor influencing other material properties of ß-InSe and γ-InSe. The existence of strong interlayer coupling manifests itself in three aspects: (i) indirect-to-direct band gap transitions with increasing layer thickness; (ii) fan-like frequency diagrams of the shear and breathing modes of few-layer flakes; and (iii) strong layer-dependent carrier mobilities. Our results indicate that multiple-layer InSe may be deserving of attention from FET-based technologies and may also be an ideal system to study interlayer coupling, possibly inherent in other 2D materials.