Exosomes are discrete populations of small (40-200 nm in diameter) membranous vesicles that are released into the extracellular space by most cell types, eventually accumulating in the circulation. ...As molecular messengers, exosomes exert a broad array of vital physiologic functions by transporting information between different cell types. Because of these functional properties, they may have potential as biomarker sources for prognostic and diagnostic disease. Recent research has found that exosomes have potential to be utilized as drug delivery agents for therapeutic targets. However, basic researches on exosomes and researches on their therapeutic potential both require the existence of effective and rapid methods for their separation from human samples. In the current absence of a standardized method, there are several methods available for the separation of exosomes, but very few studies have previously compared the efficiency and suitability of these different methods. This review summarized and compared the available traditional and novel methods for the extraction of exosomes from human samples and considered their advantages and disadvantages for use in clinical laboratories and point-of-care settings.
Fluorescence resonance energy transfer (FRET) strategy has been widely applied in designing ratiometric probes for bioimaging applications. Unfortunately, for FRET systems, sufficiently large ...spectral overlap is necessary between the donor emission and the acceptor absorption, which would limit the resolution of double-channel images. The through-bond energy transfer (TBET) system does not need spectral overlap between donor and acceptor and could afford large wavelength difference between the two emissions with improved imaging resolution and higher energy transfer efficiency than that of the classical FRET system. It seems to be more favorable for designing ratiometric probes for bioimaging applications. In this paper, we have designed and synthesized a coumarin–rhodamine (CR) TBET system and demonstrated that TBET is a convenient strategy to design an efficient ratiometric fluorescent bioimaging probe for metal ions. Such TBET strategy is also universal, since no spectral overlap between the donor and the acceptor is necessary, and many more dye pairs than that of FRET could be chosen for probe design. As a proof-of-concept, Hg2+ was chosen as a model metal ion. By combining TBET strategy with dual-switch design, the proposed sensing platform shows two well-separated emission peaks with a wavelength difference of 110 nm, high energy transfer efficiency, and a large signal-to-background ratio, which affords a high sensitivity for the probe with a detection limit of 7 nM for Hg2+. Moreover, by employing an Hg2+-promoted desulfurization reaction as recognition unit, the probe also shows a high selectivity to Hg2+. All these unique features make it particularly favorable for ratiometric Hg2+ sensing and bioimaging applications. It has been preliminarily used for a ratiometric image of Hg2+ in living cells and practical detection of Hg2+ in river water samples with satisfying results.
Here, we propose an efficient strategy for enzyme- and hairpin-free nucleic acid detection called an entropy beacon (abbreviated as Ebeacon). Different from previously reported DNA ...hybridization/displacement-based strategies, Ebeacon is driven forward by increases in the entropy of the system, instead of free energy released from new base-pair formation. Ebeacon shows high sensitivity, with a detection limit of 5 pM target DNA in buffer and 50 pM in cellular homogenate. Ebeacon also benefits from the hairpin-free amplification strategy and zero-background, excellent thermostability from 20 °C to 50 °C, as well as good resistance to complex environments. In particular, based on the huge difference between the breathing rate of a single base pair and two adjacent base pairs, Ebeacon also shows high selectivity toward base mutations, such as substitution, insertion, and deletion and, therefore, is an efficient nucleic acid detection method, comparable to most reported enzyme-free strategies.
Vascular smooth muscle cell (SMC) proliferation contributes to neointima formation following vascular injury. Circular RNA-a novel type of noncoding RNA with closed-loop structure-exhibits cell- and ...tissue-specific expression patterns. However, the role of circular RNA in SMC proliferation and neointima formation is largely unknown. The objective of this study is to investigate the role and mechanism of circSOD2 in SMC proliferation and neointima formation. Approach and Results: Circular RNA profiling of human aortic SMCs revealed that PDGF (platelet-derived growth factor)-BB up- and downregulated numerous circular RNAs. Among them, circSOD2, derived from back-splicing event of SOD2 (superoxide dismutase 2), was significantly enriched. Knockdown of circSOD2 by short hairpin RNA blocked PDGF-BB-induced SMC proliferation. Inversely, circSOD2 ectopic expression promoted SMC proliferation. Mechanistically, circSOD2 acted as a sponge for miR-206, leading to upregulation of NOTCH3 (notch receptor 3) and NOTCH3 signaling, which regulates cyclin D1 and CDK (cyclin-dependent kinase) 4/6. In vivo studies showed that circSOD2 was induced in neointima SMCs in balloon-injured rat carotid arteries. Importantly, knockdown of circSOD2 attenuated injury-induced neointima formation along with decreased neointimal SMC proliferation.
CircSOD2 is a novel regulator mediating SMC proliferation and neointima formation following vascular injury. Therefore, circSOD2 could be a potential therapeutic target for inhibiting the development of proliferative vascular diseases.
Six different polyoxotungstate-based transition metal complexes were synthesized, namely Cu
5
(2,2′-bpy)
5
(μ
2
-Cl)
2
(PO
4
)
2
(H
2
O)
2
HPW
12
O
40
·2H
2
O (
1
), Cu
1.5
(2,2′-bpy)
1.5
(inic)
2
(H
...2
O)
1.5
3
H
1.5
PW
12
O
40
2
·16.25H
2
O (
2
), Cu(2,2′-bpy)
2
2
SiW
12
O
40
·10H
2
O (
3
), Zn(phen)
3
2
PW
V
W
VI
11
O
40
·5H
2
O (
4
), Zn(phen)
2
(H
2
O)
2
SiW
12
O
40
·2H
2
O (
5
), and Zn(2,2′-bpy)
2
2
SiW
12
O
40
(
6
) (2,2′-bpy = 2,2′-bipyridine, inic = isonicotinic acid, phen = 1,10-phenanthroline). Compound
1
is based on HPW
12
O
40
2−
anions, which are accommodated within the open channels of a supramolecular network formed by novel Cu-P-Cl coordination clusters. Compound
2
is constructed from H
1.5
PW
12
O
40
1.5−
and novel Cu
1.5
(2,2′-bpy)
1.5
(inic)
2
(H
2
O)
1.5
+
coordination fragments, and polyoxoanions are encapsulated within the pores created by the copper coordination fragments, resulting in a unique three-dimensional supramolecular architecture. Compound
3
is a two-dimensional structure formed through the covalent linkage between SiW
12
O
40
4−
and Cu(2,2′-bpy)
2
2+
. Compound
4
is a supramolecular architecture formed by PW
V
W
VI
11
O
40
4−
and Zn(phen)
3
2+
coordination fragments, while compound
5
is a supramolecular structure based on POM bi-supported Zn coordination complexes. Compound
6
is a two-dimensional framework structure constituted by SiW
12
O
40
4−
and Zn(2,2′-bpy)
2
2+
via
covalent interactions. In addition, electrochemical measurement results show that the copper-based tungstate compounds
1-3
and zinc-based tungstate compounds
4-6
exhibit different performances and durabilities as electrochemical capacitors (compound
1
shows the highest specific capacitance of 94.0 F g
−1
at 1.5 A g
−1
, whereas compound
6
maintains the best cycling stability with the capacity retention of 80.7% after 1000 cycles at 4 A g
−1
.). This study contributes to the development of POM-based transition metal complexes with high capacitance by providing insights into the design and synthesis process.
Six different polyoxotungstate-based transition metal complexes were synthesized through hydrothermal methods. The electrochemical analyses show that compounds
1-6
exhibit different performances and durabilities as electrochemical capacitors.
In this study, we design various bi- and trimetallic CoIII complexes as catalysts for the ring-opening copolymerization of phthalic anhydride or CO2 (A) with terminal epoxides (B). A trimetallic ...catalyst with flexible linking groups prefers consecutive epoxide insertion and the formation of AB n ether sequences. Sequence-controlled polymers with evenly distributed backbone ether groups are produced with a broad substrate scope, resulting in a single-glass transition and tunable properties. This new class of polymers featuring controlled AB n sequences cannot be obtained using traditional catalysts, which tend to favor alternating AB structures. Further, copolymer chains possessing both alternating AB and nonalternating AB n structures could have potential applications as miscibility-promoting agents in mixed polyether/polyester systems.
Three compounds based on Ge-V-O clusters were hydrothermally synthesized and characterized by IR, UV-Vis, XRD, ESR, elemental analysis and X-ray crystal structural analysis. Both ...Cd(phen)(en)2Cd2(phen)2V12O40Ge8(OH)8(H2O)∙12.5H2O (1) and Cd(DETA)2Cd(DETA)20.5Cd2(phen)2V12O41Ge8(OH)7(0.5H2O)∙7.5H2O (2) (1,10-phen = 1,10-phenanthroline, en = ethylenediamine, DETA = diethylenetriamine) are the first Ge-V-O cluster compounds containing aromatic organic ligands. Compound 1 is the first dimer of Ge-V-O clusters, which is linked by a double bridge of two Cd(phen)(en)2+. Compound 2 exhibits an unprecedented 1-D chain structure formed by Ge-V-O clusters and Cd2(DETA)24+ transition metal complexes (TMCs). Cd(en)3{Cd(η2-en)23Cd(η2-en)(η2-μ2-en)(η2-en)CdGe6V15O48(H2O)}∙5.5H2O (3) is a novel 3-D structure which is constructed from Ge6V15O48(H2O)12− and four different types of TMCs. We also synthesized Zn2(enMe)3Zn(enMe)2Zn(enMe)2(H2O)2Ge6V15O48(H2O)∙3H2O (4) and Cd(en)22{H8Cd(en)2Ge8V12O48(H2O)}∙6H2O (5) (enMe = 1,2-propanediamine), which have been reported previously. In addition, the catalytic properties of these five compounds for styrene epoxidation have been assessed.
Display omitted
Four polyoxoniobate-based compounds, namely Cu(en)24Cu(en)2(H2O)VNb12V4O44·2.25H2O·3OH– (1), Cu(en)24Cu(en)2(H2O)3Cu(en)2(H2O)23{SiNb12Sb2O402}·25H2O (2), ...Cu(en)22Cu(en)2(H2O)24SiNb12V2O42·7H2O (3), and Cu(en)23{Cu(en)2H2V4Nb6O30}·12H2O (4) have been successfully synthesized and characterized by using FT-IR, XRD, and single crystal X-ray diffraction analyses, etc. Out of the four compounds, compound 1 is based on a rare four V capped polyoxoniobate cluster VNb12V4O447−, Cu(en)22+, and Cu(en)2(H2O)2+ complexes, forming a 1-D chain structure with Cu complexes as bridges. Compound 2 contains a Keggin polyoxoniobate with double Sb caps, and forming a network structure based on Sb capped polyoxoniobates and copper complexes with two different large parallelogram channels. Compounds 3 and 4 have been reported previously by Wang et al1 and Hu et al2, respectively. In this work, we not only reported the syntheses, structures and characterizations of these compounds, but also we further investigated the catalytic properties of these four compounds for styrene epoxidation.
Three new multifunctional isopolyniobates based on {Nb24O72}, namely, Cu(en)29.75Cu(en)2(H2O)4KNb24O72H9.252·36.5H2O (1), Cu(en)2Cu(en)2(H2O)12Cu(en)2(H2O)23KNb24O72H7(H2O)22·99H2O (2), and ...K(H2O)4Cu(en)2(H2O)25Cu(en)2(H2O)8.25Cu(en)22K0.5Nb24O72H7.752·115.31H2O (3) (en = ethylenediamine), were obtained and characterized by IR, powder X-ray diffraction, single-crystal diffraction analysis, etc. Single-crystal analyses of the three compounds shows that all their clusters exhibit the same bowl-shaped structure, while the different transition metal complexes (TMCs) make compounds 1–3 show three entirely different packing structures. The catalytic properties of the three compounds as catalysts for Rhodamine B (RhB) photocatalytic degradation, styrene oxidation, and oxygen evolution reaction (OER) have been assessed, and all the compounds have good catalytic effects on the three different catalytic processes.
PDF
