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1.
Nano Lett ; 24(17): 5197-5205, 2024 May 01.
Article in English | MEDLINE | ID: mdl-38634879

ABSTRACT

Highly active nonprecious-metal single-atom catalysts (SACs) toward catalytic transfer hydrogenation (CTH) of α,ß-unsaturated aldehydes are of great significance but still are deficient. Herein, we report that Zn-N-C SACs containing Zn-N3 moieties can catalyze the conversion of cinnamaldehyde to cinnamyl alcohol with a conversion of 95.5% and selectivity of 95.4% under a mild temperature and atmospheric pressure, which is the first case of Zn-species-based heterogeneous catalysts for the CTH reaction. Isotopic labeling, in situ FT-IR spectroscopy, and DFT calculations indicate that reactants, coabsorbed at the Zn sites, proceed CTH via a "Meerwein-Ponndorf-Verley" mechanism. DFT calculations also reveal that the high activity over Zn-N3 moieties stems from the suitable adsorption energy and favorable reaction energy of the rate-determining step at the Zn active sites. Our findings demonstrate that Zn-N-C SACs hold extraordinary activity toward CTH reactions and thus provide a promising approach to explore the advanced SACs for high-value-added chemicals.

2.
Neuron ; 111(22): 3634-3649.e7, 2023 11 15.
Article in English | MEDLINE | ID: mdl-37683629

ABSTRACT

Blood-brain barrier (BBB) function deteriorates during aging, contributing to cognitive impairment and neurodegeneration. It is unclear what drives BBB leakage in aging and how it can be prevented. Using single-nucleus transcriptomics, we identified decreased connexin 43 (CX43) expression in cadherin-5+ (Cdh5+) cerebral vascular cells in naturally aging mice and confirmed it in human brain samples. Global or Cdh5+ cell-specific CX43 deletion in mice exacerbated BBB dysfunction during aging. The CX43-dependent effect was not due to its canonical gap junction function but was associated with reduced NAD+ levels and mitochondrial dysfunction through NAD+-dependent sirtuin 3 (SIRT3). CX43 interacts with and negatively regulates poly(ADP-ribose) polymerase 1 (PARP1). Pharmacologic inhibition of PARP1 by olaparib or nicotinamide mononucleotide (NMN) supplementation rescued NAD+ levels and alleviated aging-associated BBB leakage. These findings establish the endothelial CX43-PARP1-NAD+ pathway's role in vascular aging and identify a potential therapeutic strategy to combat aging-associated BBB leakage with neuroprotective implications.


Subject(s)
Connexin 43 , NAD , Animals , Humans , Mice , Aging/physiology , Blood-Brain Barrier/metabolism , Brain/metabolism , Connexin 43/genetics , Connexin 43/metabolism , NAD/metabolism , Poly (ADP-Ribose) Polymerase-1/metabolism
3.
Adv Healthc Mater ; 12(26): e2300883, 2023 10.
Article in English | MEDLINE | ID: mdl-37437241

ABSTRACT

The fast renal clearance of hydrophilic small molecular anticancer drugs and ultrasmall nanoparticles (NPs) results in the low utilization rate and certain side effects, thus improving the tumor targeting is highly desired but faces great challenges. A novel and general ß-cyclodextrin (CD) aggregation-induced assembly strategy to fabricate doxorubicin (DOX) and CD-coated NPs (such as Au) co-encapsulated pH-responsive nanocomposites (NCs) is proposed. By adding DOX×HCl and reducing pH in a reversed microemulsion system, hydrophilic CD-coated AuNPs rapidly assemble into large NCs. Then in situ polymerization of dopamine and sequentially coordinating with Cu2+ on the surface of NCs provide extra weak acid responsiveness, chemodynamic therapy (CDT), and improved biocompatibility as well as stability. The subsequent tumor microenvironment responsive dissociation notably improves their passive tumor targeting, bioavailability, imaging, and therapeutic capabilities, as well as facilitates their internalization by tumor cells and metabolic clearance, thereby reducing side effects. The combination of polymerized dopamine and assembled AuNPs reinforces photothermal capability, thus further boosting CDT through thermally amplifying Cu-catalyzed Fenton-like reaction. Both in vitro and in vivo studies confirm the desirable outcomes of these NCs as photoacoustic imaging guided trimodal (thermally enhanced CDT, photothermal therapy, and chemotherapy) synergistic tumor treatment agents with minimal systemic toxicity.


Subject(s)
Hyperthermia, Induced , Metal Nanoparticles , Nanoparticles , Neoplasms , Humans , Gold , Dopamine/therapeutic use , Hyperthermia, Induced/methods , Neoplasms/diagnostic imaging , Neoplasms/drug therapy , Nanoparticles/chemistry , Doxorubicin/pharmacology , Doxorubicin/therapeutic use , Cell Line, Tumor , Tumor Microenvironment
4.
Adv Sci (Weinh) ; 10(26): e2302123, 2023 09.
Article in English | MEDLINE | ID: mdl-37449329

ABSTRACT

Cardiovascular disease is the leading cause of death worldwide. Reperfusion therapy is vital to patient survival after a heart attack but can cause myocardial ischemia/reperfusion injury (MI/RI). Nitric oxide (NO) can ameliorate MI/RI and is a key molecule for drug development. However, reactive oxygen species (ROS) can easily oxidize NO to peroxynitrite, which causes secondary cardiomyocyte damage. Herein, L-arginine-loaded selenium-coated gold nanocages (AAS) are designed, synthesized, and modified with PCM (WLSEAGPVVTVRALRGTGSW) to obtain AASP, which targets cardiomyocytes, exhibits increased cellular uptake, and improves photoacoustic imaging in vitro and in vivo. AASP significantly inhibits oxygen glucose deprivation/reoxygenation (OGD/R)-induced H9C2 cell cytotoxicity and apoptosis. Mechanistic investigation revealed that AASP improves mitochondrial membrane potential (MMP), restores ATP synthase activity, blocks ROS generation, and prevents NO oxidation, and NO blocks ROS release by regulating the closing of the mitochondrial permeability transition pore (mPTP). AASP administration in vivo improves myocardial function, inhibits myocardial apoptosis and fibrosis, and ultimately attenuates MI/RI in rats by maintaining mitochondrial function and regulating NO signaling. AASP shows good safety and biocompatibility in vivo. This findings confirm the rational design of AASP, which can provide effective treatment for MI/RI.


Subject(s)
Myocardial Reperfusion Injury , Rats , Animals , Myocardial Reperfusion Injury/drug therapy , Myocardial Reperfusion Injury/metabolism , Nitric Oxide/metabolism , Reactive Oxygen Species/therapeutic use , Gold , Arginine/metabolism , Mitochondria/metabolism
5.
Signal Transduct Target Ther ; 8(1): 55, 2023 02 03.
Article in English | MEDLINE | ID: mdl-36737432

ABSTRACT

Aortic aneurysm is a chronic aortic disease affected by many factors. Although it is generally asymptomatic, it poses a significant threat to human life due to a high risk of rupture. Because of its strong concealment, it is difficult to diagnose the disease in the early stage. At present, there are no effective drugs for the treatment of aneurysms. Surgical intervention and endovascular treatment are the only therapies. Although current studies have discovered that inflammatory responses as well as the production and activation of various proteases promote aortic aneurysm, the specific mechanisms remain unclear. Researchers are further exploring the pathogenesis of aneurysms to find new targets for diagnosis and treatment. To better understand aortic aneurysm, this review elaborates on the discovery history of aortic aneurysm, main classification and clinical manifestations, related molecular mechanisms, clinical cohort studies and animal models, with the ultimate goal of providing insights into the treatment of this devastating disease. The underlying problem with aneurysm disease is weakening of the aortic wall, leading to progressive dilation. If not treated in time, the aortic aneurysm eventually ruptures. An aortic aneurysm is a local enlargement of an artery caused by a weakening of the aortic wall. The disease is usually asymptomatic but leads to high mortality due to the risk of artery rupture.


Subject(s)
Aortic Aneurysm, Abdominal , Aortic Rupture , Animals , Humans , Aortic Aneurysm, Abdominal/surgery , Aortic Rupture/genetics , Aortic Rupture/therapy , Cohort Studies
6.
Pharmacol Res ; 187: 106586, 2023 01.
Article in English | MEDLINE | ID: mdl-36460280

ABSTRACT

Over the past few decades, the treatment of atherosclerotic cardiovascular disease has mainly been through an LDL lowering strategy and treatments targeting other traditional risk factors for atherosclerosis, which has significantly reduced cardiovascular mortality. However, the overall benefit of targeting these risk factors has stagnated, and the discovery of new therapeutic targets for atherosclerosis remains a challenge. Accumulating evidence from clinical and animal experiments has revealed that the gut microbiome play a significant role in human health and disease, including cardiovascular diseases. The gut microbiome contribute to host health and disease through microbial composition and function. The gut microbiome function like an endocrine organ by generating bioactive metabolites that can impact atherosclerosis. In this review, we describe two gut microbial metabolites/pathways by which the gut affects atherosclerotic cardiovascular disease. On the one hand, we discuss the effects of trimethylamine oxide (TMAO), bile acids and aromatic amino acid metabolites on the development of atherosclerosis, and the protective effects of beneficial metabolites short chain amino acids and polyamines on atherosclerosis. On the other hand, we discuss novel therapeutic strategies for directly targeting gut microbial metabolites to improve cardiovascular outcomes. Reducing gut-derived TMAO levels and interfering with the bile acid receptor farnesoid X receptor (FXR) are new therapeutic strategies for atherosclerotic disease. Enzymes and receptors in gut microbiota metabolic pathways are potential new drug targets. We need solid insight into these underlying mechanisms to pave the way for therapeutic strategies targeting gut microbial metabolites/pathways for atherosclerotic cardiovascular disease.


Subject(s)
Atherosclerosis , Cardiovascular Diseases , Gastrointestinal Microbiome , Animals , Humans , Cardiovascular Diseases/etiology , Methylamines/metabolism , Atherosclerosis/diagnosis , Atherosclerosis/drug therapy , Atherosclerosis/complications
7.
FASEB J ; 36(6): e22340, 2022 06.
Article in English | MEDLINE | ID: mdl-35524736

ABSTRACT

The prevention role of Lactiplantibacillus plantarum against the formation of kidney stones has been increasingly recognized; its mechanism, however, has mainly been focused on inhibiting the inflammation in the colon in the gastrointestinal (GI) system, and the intestinal metabolites from microflora have not been revealed fully with regarding to the stone formation. In this study, we investigated the effect of L. plantarum J-15 on kidney stone formation in renal calcium oxalate (CaOx) rats induced by ethylene glycol and monitored the changes of intestinal microflora and their metabolites detected by 16S rRNA sequencing and widely targeted analysis, followed by the evaluation of the intestinal barrier function and inflammation levels in the colon, blood and kidney. The results showed that L. plantarum J-15 effectively reduced renal crystallization and urinary oxalic acid. Ten microbial genera, including anti-inflammatory and SCFAs-related Faecalibaculum, were enriched in the J-15 treatment group. There are 136 metabolites from 11 categories significantly different in the J-15 supplementation group compared with CaOx model rats, most of which were enriched in the amino acid metabolic and secondary bile acid pathways. The expression of intestinal tight junction protein Occludin and the concentration of pro-inflammatory cytokines and prostaglandin were decreased in the intestine, which further reduced the translocated lipopolysaccharide and inflammation levels in the blood upon J-15 treatment. Thus, the inflammation and injury in the kidney might be alleviated by downregulating TLR4/NF-κB/COX-2 signaling pathway. It suggested that L. plantarum J-15 might reduce kidney stone formation by restoring intestinal microflora and metabolic disorder, protecting intestinal barrier function, and alleviating inflammation. This finding provides new insights into the therapies for renal stones.


Subject(s)
Gastrointestinal Microbiome , Kidney Calculi , Animals , Calcium Oxalate/metabolism , Female , Humans , Inflammation/metabolism , Kidney Calculi/chemically induced , Kidney Calculi/prevention & control , Lactobacillaceae/genetics , Lactobacillaceae/metabolism , Male , RNA, Ribosomal, 16S/genetics , Rats
8.
Anal Chem ; 94(8): 3727-3734, 2022 03 01.
Article in English | MEDLINE | ID: mdl-35184546

ABSTRACT

The real-time tracking and efficacy evaluation of therapeutic nanoplatforms especially in deep-tissues is of great importance but faces challenges. Meanwhile, chemodynamic therapy (CDT), relying on Fenton reaction by converting H2O2 into toxic hydroxyl radicals (•OH), has drawn wide interests in the fabrication of nanozymes for tumor therapy, while endogenous H2O2 is usually insufficient for effective CDT. Here, we report the pH-responsive multifunctional nanoplatforms consisting of copper peroxide (CP) nanoparticles, paclitaxel (PTX) and perfluoro-15-crown-5-ether (PFCE), for 19F magnetic resonance imaging guided and enhanced chemo-chemodynamic synergetic therapy with self-supplied H2O2 stemmed from the decomposition of CP nanoparticles under acid conditions in tumor. The decomposition of CP nanoparticles further promotes the release of PTX for enhanced chemotherapy. Both in vitro and in vivo results indicate that the efficient generation of •OH and drug release effectively inhibits tumor growth. Furthermore, 19F MRI signal can clearly track the fate of nanoplatforms in tumor and guide tumor treatment. This work provides a promising strategy for the rational design and construction of multifunctional nanoplatforms for imaging-guided synergistic therapy of deep seated tumor.


Subject(s)
Hydrogen Peroxide , Nanoparticles , Cell Line, Tumor , Hydroxyl Radical , Magnetic Resonance Imaging
9.
ACS Appl Mater Interfaces ; 13(17): 20094-20104, 2021 May 05.
Article in English | MEDLINE | ID: mdl-33890773

ABSTRACT

The design of low-cost yet highly efficient electrocatalysts plays a critical role in energy storage and conversion reactions. The oxygen evolution reaction (OER) is considered a bottleneck of electrochemical water splitting for hydrogen fuel generation. It is still challenging to extract a high density of charge carriers in noble-metal-free alternative catalysts to facilitate sluggish kinetics. Herein, we report the rational design and coherent interface engineering for combining light-harvesting Cu31S16 with electroactive Co9-xNixS8 (x = 0-9) to form novel Cu31S16-Co9-xNixS8 heterodimers. By delicately controlling the kinetic growth in a seed-mediated growth method, the bifunctional centers, even with two distinct crystal phases, were integrated into a synergistic architecture, which achieved full-spectrum solar energy capture and light conversion to drive and activate the electrochemical reaction. Benefiting from the well-defined structure, high-quality interface, oriented attachment, and optimal Co/Ni bimetal ratio, Cu31S16-Co7.2Ni1.8S8 produces a dramatically reduced overpotential (242 mV at 10 mA cm-2) with a shift of 83 mV under visible-light excitation, achieving a 4.5-fold higher turnover frequency than that of its unirradiated Co7.2Ni1.8S8 counterpart. This enhanced performance also far exceeds commercial RuO2 (358 mV at 10 mA cm-2) and most nonprecious-metal nanocatalysts. Further mechanistic studies reveal that coherent interface engineering leads to a strong photo/electricity coupling effect and efficient spatial charge separation, which induces sufficient hot holes that eventually accumulate at the electroactive sites to accelerate the multihole-involved OER. This work would open up new opportunities for the fabrication of non-noble metal electrocatalysts and management of charge carriers.

10.
Anal Chem ; 92(17): 11739-11746, 2020 09 01.
Article in English | MEDLINE | ID: mdl-32786481

ABSTRACT

Multiresponsive nanoprobes are highly desirable for low background and highly sensitive imaging in biomedical applications. Herein, we design a glutathione (GSH)/pH dual-responsive nanoprobe capable of both fluorescence imaging in cells and 19F magnetic resonance imaging (19F MRI) in deep tissue, by encapsulating manganese oleate (Mn(OA)2) on the surface of fluorinated fluorescent quantum dots (F-ZnS:Mn2+). In this approach, Mn(OA)2 serves as an efficient quencher of both fluorescence and 19F MRI signal. Both the fluorescence and 19F MRI signal can be turned on by introducing glutathione (GSH) that breaks up the Mn-O bonds within Mn(OA)2 under weak acidity conditions (e.g., pH 6.0). The imaging results in cells and mice suggest that this novel strategy can offer a promising nanoprobe for turn-on fluorescence/19F MRI dual-modal tumor imaging.


Subject(s)
Magnetic Resonance Imaging/methods , Nanomedicine/methods , Optical Imaging/methods , Fluorescence , Humans , Quantum Dots/chemistry
11.
ACS Omega ; 5(14): 8373-8379, 2020 Apr 14.
Article in English | MEDLINE | ID: mdl-32309748

ABSTRACT

Hydrogen sulfide (H2S) is considered as a highly toxic environmental pollutant and an important signal transmitter in physiological processes, and the selective and reliable detection of H2S is of great concern and remains challenging. Herein, we report a smart sensitive "off-on" 19F NMR sensor for H2S by partially introducing a fluorinated ligand to construct a hollow dual metal-organic framework (MOF) nanosystem, F-ZnFeIII hMOF, in which the fluorinated ligand acts as the 19F signal source but is initially quenched due to the strong paramagnetic relaxation enhancement (PRE) effect from neighboring Fe3+ nodes. Upon exposure to sulfide ions, reduction of Fe3+ to Fe2+ is specifically triggered, which attenuates PRE efficiency, thus turning on the 19F NMR signal. The unique hollow MOF architecture benefits the mobility of 19F atoms, thereby improving the response sensitivity. Meanwhile, the desirable H2S-sorption feature and appropriate redox potential of Fe3+/Fe2+ account for the favorable selectivity. The increase in the 19F signal is linear with the concentration of sulfide in the range of 20 to 150 µM with a detection limit of 2.8 µM. The probe is well demonstrated by analyzing H2S in complex matrixes such as biological and foodstuff samples.

12.
J Am Chem Soc ; 140(37): 11594-11598, 2018 09 19.
Article in English | MEDLINE | ID: mdl-30168714

ABSTRACT

Single-atom metal-nitrogen-carbon (M-N-C) catalysts have sparked intense interests, but the catalytic contribution of N-bonding environment neighboring M-N4 sites lacks attention. Herein, a series of Fe-N-C nanoarchitectures have been prepared, which confer adjustable numbers of atomically dispersed Fe-N4 sites, tunable hierarchical micro-mesoporous structures and intensified exposure of interior active sites. The optimization between Fe-N4 single sites and carbon matrix delivers superior oxygen reduction reaction activity (half-wave potential of 0.915 V vs RHE in alkaline medium) with remarkable stability and high atom-utilization efficiency (almost 10-fold enhancement). Both experiments and theoretical calculations verified the selective C-N bond cleavage adjacent to Fe center induced by porosity engineering could form edge-hosted Fe-N4 moieties, and therefore lower the overall oxygen reduction reaction barriers comparing to intact atomic configuration. These findings provide a new pathway for the integrated engineering of geometric and electronic structures of single-atom materials to improve their catalytic performance.

13.
Food Chem ; 269: 342-346, 2018 Dec 15.
Article in English | MEDLINE | ID: mdl-30100444

ABSTRACT

Furan, which has been identified as a carcinogenic risk for humans, can be induced in different foods by UV-C light. In this study, we hypothesized that furan was produced by a UV light-induced free radical mechanism and antioxidants could suppress its formation. Our results demonstrated that, by adding antioxidants, such as butylated hydroxyl toluene, ascorbic acid or gallic acid, to simulated juice or apple cider during UV-C treatment, amounts of furan were significantly reduced. For example, the concentration of furan produced in apple cider by UV-C at 9.0 J/cm2 was 636 ppb but was less than 20 ppb with 0.25 ppm butylated hydroxyl toluene present, less than 3 ppb with 0.5% (w/v) ascorbic acid, and less than 1.0 ppb with 0.5% (w/v) gallic acid. These findings confirmed that antioxidants can be used as a safe and simple mitigation measure to control furan production in fruit drinks exposed to UV-light.


Subject(s)
Food Handling/methods , Furans/chemical synthesis , Malus/chemistry , Ultraviolet Rays , Antioxidants , Ascorbic Acid , Beverages/analysis , Humans , Sugars
14.
J Mater Chem B ; 6(47): 7936-7942, 2018 Dec 21.
Article in English | MEDLINE | ID: mdl-32255039

ABSTRACT

Metal-organic frameworks (MOFs) have been widely used for drug/dye loading, but the large scale continuous production of these nanoparticles with good stability and biocompatibility still faces great challenges. Herein, a thermal-assisted microfluidic system was developed for the continuous and scalable fabrication of drug loaded MOFs@SiO2 nanoparticles with uniform shape, narrow size distribution, good stability and excellent biocompatibility. This facile and general strategy is readily employed in the encapsulation of many dyes and drugs. In vivo photodynamic therapy for cancers, based on rose bengal-loaded nanoparticles, demonstrates the great potential of this novel fabrication strategy in biomedical fields.

15.
ACS Appl Mater Interfaces ; 8(35): 22830-8, 2016 Sep 07.
Article in English | MEDLINE | ID: mdl-27534896

ABSTRACT

(19)F magnetic resonance imaging (MRI), due to its high sensitivity and negligible background, is anticipated to be a powerful noninvasive, sensitive, and accurate molecular imaging technique. However, the major challenge of (19)F MRI is to increase the number of (19)F atoms while maintaining the solubility and molecular mobility of the probe. Here, we successfully developed a facile and general strategy to synthesize the multifunctional (19)F MRI nanoprobes by encapsulating the hydrophobic inorganic nanoparticles (NPs) into a hybrid polymer micelle consisting of hydrolysates of 1H,1H,2H,2H-perfluorodecyltriethoxysilane (PDTES) and oleylamine-functionalized poly(succinimide) (PSIOAm). Due to their good water dispersibility, excellent molecular mobility resulting from the ultrathin coating, and high (19)F atom numbers, these nanoprobes generate a separate sharp singlet of (19)F nuclear magnetic resonance (NMR) signal (at -82.8 ppm) with half peak width of ∼28 Hz, which is highly applicable for (19)F MRI. Significantly, by varying the inorganic core from metals (Au), oxides (Fe3O4), fluorides (NaYF4:Yb(3+)/Er(3+)), and phosphates (YPO4) to semiconductors (Cu7S4 and Ag2S, ZnS:Mn(2+)) NPs, which renders the nanoprobes' multifunctional properties such as photothermal ability (Au, Cu7S4), magnetism (Fe3O4), fluorescence (ZnS:Mn(2+)), near-infrared (NIR) fluorescence (Ag2S), and upconversion (UC) luminescence. Meanwhile, the as-prepared nanoprobes possess relatively small sizes (about 50 nm), which is beneficial for long-time circulation. The proof-of-concept in vitro (19)F NMR and photothermal ablation of ZnS:Mn(2+)@PDTES/PSIOAm and Cu7S4@PDTES/PSIOAm nanoprobes further suggest that these nanoprobes hold wide potentials for multifunctional applications in biomedical fields.


Subject(s)
Optical Imaging , Fluorides , Luminescence , Magnetic Resonance Imaging , Nanoparticles
16.
Anal Chem ; 88(15): 7853-7, 2016 08 02.
Article in English | MEDLINE | ID: mdl-27349933

ABSTRACT

The use of fluorescence probes for biomedical imaging has attracted significant attention over recent years owing to their high resolution at cellular level. The probes are available in many formats including small particle size based imaging agents which are considered to be promising candidates, due to their excellent stabilities. Yet, concerns over the potential cytotoxicity effects of inorganic luminescent particles have led to questions about their suitability for imaging applications. Exploration of alternatives inspired us to use organic fluorophores with aggregation-induced emission (AIE), prepared by functionalizing the amine group on tetraphenylethene with 3,5-bis(trifluoromethyl)phenyl isocyanate. The as-synthesized novel AIE fluorophore (TPE-F) display enhanced quantum yield and longer lifetime as compared with its counterparts (4,4',4″,4‴-(ethene-1,1,2,2-tetrayl)tetraaniline, TPE-AM). Furthermore, the TPE-F was encapsulated into small-size organic nanoparticles (NPs; dynamic light scattering size, ∼10 nm) with polysuccinimide (PSI). The biocompatibility, excellent stability, bright fluorescence, and selective cell targeting of these NPs enable the as-prepared TPE-F NPs to be suitable for specific fluorescence cell imaging.


Subject(s)
Fluorescent Dyes/chemistry , Microscopy, Confocal , Nanoparticles/chemistry , Dynamic Light Scattering , HeLa Cells , Humans , Magnetic Resonance Spectroscopy , Polymers/chemistry
17.
ACS Nano ; 10(1): 1355-62, 2016 Jan 26.
Article in English | MEDLINE | ID: mdl-26741791

ABSTRACT

(19)F magnetic resonance imaging (MRI) is a powerful noninvasive, sensitive, and accurate molecular imaging technique for early diagnosis of diseases. The major challenge of (19)F MRI is signal attenuation caused by the reduced solubility of probes with increased number of fluorine atoms and the restriction of molecular mobility. Herein, we present a versatile one-pot strategy for the fabrication of a multifunctional nanoprobe with high (19)F loading (∼2.0 × 10(8 19)F atoms per Cu1.75S nanoparticle). Due to the high (19)F loading and good molecular mobility that results from the small particle size (20.8 ± 2.0 nm) and ultrathin polymer coating, this nanoprobe demonstrates ultrahigh (19)F MRI signal. In vivo tests show that this multifunctional nanoprobe is suitable for (19)F MRI and photothermal therapy. This versatile fabrication strategy has also been readily extended to other single-particle nanoprobes for ablation and sensitive multimodal imaging.


Subject(s)
Copper/chemistry , Fluorine-19 Magnetic Resonance Imaging/methods , Mammary Neoplasms, Experimental/therapy , Nanoparticles/chemistry , Phototherapy/methods , Animals , Cell Survival/drug effects , Contrast Media/administration & dosage , Female , Fluorine Radioisotopes/administration & dosage , HeLa Cells , Humans , Injections, Subcutaneous , Mammary Glands, Animal , Mammary Neoplasms, Experimental/pathology , Mice , Mice, Inbred BALB C , Nanoparticles/administration & dosage , Nanoparticles/ultrastructure , Particle Size
18.
Food Chem ; 192: 9-14, 2016 Feb 01.
Article in English | MEDLINE | ID: mdl-26304314

ABSTRACT

A headspace solid phase microextraction (HS-SPME) procedure followed by gas chromatography-flame ionisation detector (GC-FID) analysis was developed and validated for the simultaneous analysis of furan, 2-methylfuran and 2-pentylfuran from juice samples. Extraction at 32 °C for 20 min with stirring at 600 rpm and NaCl concentration 15% (W/V) was the optimal HS-SPME condition for all the three compounds by using a carboxen/polydimethylsiloxane fused silica fibre (75 µm). The extracted compounds were base line separated on a SPB-1 GC column within 12 min. The relative standard deviations of all analytes were less than 6.7%. The recovery rates were between 90.2% and 110.1%. The limits of detection and limits of quantification were 0.056-0.23 ng/mL and 0.14-0.76 ng/mL, respectively. The results showed that the developed method was sensitive, precise, accurate and robust for the determination of furan, 2-methylfuran and 2-pentylfuran in complex matrices without interferences from other components.


Subject(s)
Flame Ionization/methods , Fruit and Vegetable Juices/analysis , Furans/chemistry , Solid Phase Microextraction/methods , Chromatography, Gas/methods , Gas Chromatography-Mass Spectrometry/methods
19.
Anal Chem ; 88(2): 1434-9, 2016 Jan 19.
Article in English | MEDLINE | ID: mdl-26691536

ABSTRACT

Aqueous sulfides are emerging signaling agents implicated in various pathological and physiological processes. The development of sensitive and selective methods for the sensing of these sulfides is therefore very important. Herein, we report that the as-synthesized 1-oxo-1H-phenalene-2,3-dicarbonitrile (OPD) compound provides promising fluorescent properties and unique reactive properties toward aqueous sulfides. It was found that OPD showed high selectivity and sensitivity toward Na2S over thiols and other inorganic sulfur compounds through a sulfide involved reaction which was confirmed by high-resolution mass spectroscopy (HRMS) and nuclear magnetic resonance (NMR) results. The fluorescence intensity increases linearly with sulfide concentration in the range of 1.0-30 µM with a limit of detection of 52 nM. This novel fluorescent probe was further exploited for the fluorescence imaging sensing of aqueous sulfide in HeLa cells.


Subject(s)
Fluorescent Dyes/chemistry , Nitriles/chemistry , Spectrometry, Fluorescence/instrumentation , Sulfides/analysis , Cell Survival , Fluorescent Dyes/analysis , HeLa Cells , Humans , Molecular Structure , Nitriles/analysis , Sulfides/chemistry , Water/chemistry
20.
Small ; 11(33): 4183-90, 2015 Sep 02.
Article in English | MEDLINE | ID: mdl-25981697

ABSTRACT

According to the simulation, the self-assembly of Cu7 S4 nanocrystals would enhance the photothermal conversion efficiency (PCE) because of the localized surface plasmon resonance effects, which is highly desirable for photothermal therapy (PTT). A new strategy to synthesize Cu7 S4 nanosuperlattices with greatly enhanced PCE up to 65.7% under irradiation of 808 nm near infrared light is reported here. By tuning the surface properties of Cu7 S4 nanocrystals during the synthesis via thermolysis of a new single precursor, dispersed nanoparticles (NPs), rod-like alignments, and nanosuperlattices are obtained, respectively. To explore their PTT applications, these hydrophobic nanostructures are transferred into water by coating with home-made amphiphilic polymer while maintaining their original structures. Under identical conditions, the PCE are 48.62% and 56.32% for dispersed NPs and rod-like alignments, respectively. As expected, when the nanoparticles are self-assembled into nanosuperlattices, the PCE is greatly enhanced up to 65.7%. This strong PCE, along with their excellent photothermal stability and good biocompatibility, renders these nanosuperlattices good candidates as PTT agents. In vitro photothermal ablation performances have undoubtedly proved the excellent PCE of our Cu7 S4 nanosuperlattices. This research offers a versatile and effective solution to get PTT agents with high photothermal efficiency.


Subject(s)
Copper/chemistry , Phototherapy/instrumentation , Quantum Dots/chemistry , Sulfur Compounds/chemical synthesis , Antineoplastic Agents/chemistry , Antineoplastic Agents/pharmacology , Doxycycline/chemistry , Doxycycline/pharmacology , HeLa Cells , Humans , Hydrophobic and Hydrophilic Interactions , Infrared Rays , Nanostructures/chemistry , Phototherapy/methods , Sulfur Compounds/chemistry , Sulfur Compounds/pharmacology , Surface Properties
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