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1.
Artigo em Inglês | MEDLINE | ID: mdl-31718977

RESUMO

Lipid droplets (LDs) are organelles featuring in intracellular storage of neutral lipids, which are involved with many biological processes. Monitoring the dynamical cyclic behaviors of cellular LDs poses great importance for early disease diagnosis. Herein, two coumarin-based LDs-specific fluorescence probes exhibited "turn-on" and two-photon fluorescence triggered by breaking their aggregation states. By virtue of establishing oil/water emulsions model to simulate LDs, the behaviors of "turn-on" fluorescence were elucidated, which benefited for the enhancement of selectivity of the probes to LDs. Then, we highlight a LDs-specific coumarin-based two-photon probe (L1) with high photo-stability to monitor the dynamic cyclic behaviors of LDs in cells, unraveling the changes of LDs quantity during lipophagy and the reproduction of LDs to prevent lipotoxicity. We believe the probe offers a convenient way to investigate the biology of LDs.

2.
Artigo em Inglês | MEDLINE | ID: mdl-31771326

RESUMO

Photodynamic therapy (PDT) takes advantage of reactive oxygen species (ROS) to trigger the apoptosis for cancer therapy. Given cell apoptosis is a form of programmed cell death involved with multiple sub-organelles and cancer cells are more sensitive to ROS than normal cells, early confirmation of the apoptosis induced by ROS would effectively avoid overtreatment. Herein, we highlight an aggregation-induced emission (AIE) based theranostic agent (TPA3) to in-situ dynamically track mitophagy prior to late apoptosis. TPA3 showed high specificity to autophagy vacuoles (AVs), of which appearance is the signature event of mitophagy during early apoptosis, and delivered photocytotoxicity to cancer cells and skin cancer tumors in nude mice under irradiation of white light. Fur-thermore, in-situ monitoring of dynamical mitophagy process involved with mitochondria, AVs, and lysosomes was performed for the first time under confocal microscopy, providing a real-time self-monitoring system for assessing the curative effect prior to late apop-tosis. This fluorescence imaging guided PDT witness great advances for applying in the clinical application.

3.
Materials (Basel) ; 12(21)2019 Oct 25.
Artigo em Inglês | MEDLINE | ID: mdl-31731435

RESUMO

Recently, there is ongoing interest in the use of natural plant fibers as alternatives for conventional reinforcements in cementitious composites. The use of natural plant fibers makes engineering work more sustainable, since they are renewable, biodegradable, energy-efficient, and non-toxic raw materials. In this contribution, a comprehensive experimental program was undertaken to determine the influence of pineapple leaf fiber and ramie fiber on the mechanical properties and mass transport of cement-based composites. The compressive strength, tensile strength, modulus of elasticity, modulus of rupture, fracture energy, flexural toughness, coefficient of capillary water absorption, and chloride diffusion were measured. Natural plant fiber-reinforced cement-based composites (NPFRCCs) containing pineapple leaf fiber and ramie fiber, as compared to the plain control, exhibited a slight reduction in compressive strength and a considerable improvement in tensile strength, modulus of elasticity, modulus of rupture, and flexural toughness; the enhancement was remarkable with a higher fiber content. The coefficient of capillary absorption and chloride diffusion of NPFRCCs were significantly larger than the plain control, and the difference was evident with the increase in fiber content. The present study suggests that the specimen with 2% pineapple leaf fiber content can be used in normal environments due to its superior mechanical properties. However, one should be careful when using the material in marine environments.

4.
Chem Sci ; 10(30): 7228-7232, 2019 Aug 14.
Artigo em Inglês | MEDLINE | ID: mdl-31588291

RESUMO

Multiphoton bioimaging benefits from good penetration of tissue, low phototoxicity and high resolution. Hence, development of efficient multiphoton imaging agents is highly desirable but remains challenging. Herein, a novel terpyridine-based Zn(ii) complex bearing a thiophene bridge was designed rationally and fabricated. Thanks to its aggregation-induced emission (AIE), DZ1 emitted bright yellow-green fluorescence (λ em = 575 nm) under physiological conditions. The three-photon spectral changes of DZ1 when binding with RNA unambiguously reflected its RNA-specific targeting behaviour, resulting in twofold enhancement in three-photon action cross-sections located at the second near-infrared window (1700 nm).

5.
Spectrochim Acta A Mol Biomol Spectrosc ; 226: 117571, 2019 Oct 10.
Artigo em Inglês | MEDLINE | ID: mdl-31622830

RESUMO

The fabrication of two-photon absorption material is a versatile approach to achieve high resolution bioimaging with low phototoxicity yet remain sophisticated. Herein, a zwitterionic chromophore, MF, with D-π-A configuration has been rational designed and synthesized. Remarkably, MF exhibited enhanced one- and two-photon fluorescent in the aggregation states. Additionally, the obtained MFNPs encapsulated by Pluronic F-127, could be employed as a two-photon fluorescent probe for bioimaging. The results reveal that MFNPs could target mitochondria by using two-photon confocal microscopy and stimulated emission depletion nanoscopy methods.

6.
Theranostics ; 9(8): 2158-2166, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31149035

RESUMO

Platinum complexes have been used for anti-cancer propose for decades, however, their high side effects resulting from damage to healthy cells cannot be neglected and prevent further clinical utilisation. Here, we designed a cyclometalated platinum (II) complex that can bind the endogenous nuclear factor-κB (NF-κB) protein. Employing detailed colocalization studies in co-culture cell line models, we show that by binding to NF-κB, the platinum (II) complex is capable of upregulated nuclear translocation specifically in cancer but not normal cells, thereby impairing cancer proliferation without disturbing healthy cells. In a murine tumour model, the platinum (II) complex prevents tumour growth to a greater extent than cisplatin and with considerably lower side-effects and kidney damage. Considering its weak damage to normal cells combined with high toxicity to cancer cells, this NF-κB-binding platinum complex is a potential anti-cancer candidate and acts to verify the strategy of hijacking endogenous trans-nuclear proteins to achieve cancer-cell specificity and enhance therapeutic indices.

7.
Talanta ; 199: 140-146, 2019 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-30952238

RESUMO

Small molecules emitting in the NIR for tracking mitochondrial pH alteration with super-resolution are expected to play an essential role in biomedical applications. Herein, two small molecules based on pyridinium salt (P1 and P2) have been synthesized and systematically investigated. It was found that pyridinium salts P1 and P2 emitted in the NIR (about 610 nm), which could detect pH changes from 2.0 to 11.0 with good linearity and high sensitivity. Importantly, P2 could precisely target cellular mitochondria in a real-time manner under stimulated emission depletion (STED). These results implied a chemical strategy with a potential application in super-resolution imaging and mitochondrial pH determination.


Assuntos
Mitocôndrias/química , Compostos de Piridínio/química , Bibliotecas de Moléculas Pequenas/química , Cristalografia por Raios X , Células Hep G2 , Humanos , Concentração de Íons de Hidrogênio , Raios Infravermelhos , Microscopia de Fluorescência , Modelos Moleculares , Estrutura Molecular , Compostos de Piridínio/síntese química , Teoria Quântica , Bibliotecas de Moléculas Pequenas/síntese química
8.
ACS Appl Mater Interfaces ; 11(20): 18203-18212, 2019 May 22.
Artigo em Inglês | MEDLINE | ID: mdl-31026133

RESUMO

Commercial gadolinium-based materials have been widely used as contrast agents for magnetic resonance imaging (MRI), but the high toxicity of leaking free Gd3+ ions still raises biosafety concerns. Here, we develop a novel, safe, and efficient MRI contrast agent based on a stable Fe(III) complex of fluorine and nitrogen co-doped carbon dots (F,N-CDs) that was prepared from glucose and levofloxacin by a simple microwave-assisted thermal decomposition method. The obtained Fe3+@F,N-CD complex exhibits higher longitudinal relaxivity ( r1 = 5.79 mM-1·s-1) than that of the control samples of the Fe3+@CD complex ( r1 = 4.23 mM-1 s-1) and free Fe3+ ( r1 = 1.59 mM-1 s-1) in aqueous solution, as assessed by a 1.5 T NMR analyzer. More importantly, the Fe3+@F,N-CD complex is very stable with a large coordination constant of 1.06 × 107 in aqueous medium. While incubated with HeLa cells, the Fe3+@F,N-CD complex shows clear MR images, demonstrating that it has potential to be an excellent MRI contrast agent. Furthermore, in vivo MRI experiments indicate that the Fe3+@F,N-CD complex provides high-resolution MRI pictures of 4T1 tumor bearing BALB/c mice 15 min after injection and can be completely excreted 2 h after administration. No cytotoxicity was observed with F,N-CDs and Fe concentration up to 0.2 mg/mL and 0.3 mM in 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide cell proliferation assay, respectively. The possible mechanism of the enhanced MRI effect of the Fe3+@F,N-CD complex is therefore proposed. The extremely low toxicity, high r1 relaxivity, strong photoluminescence, and low synthetic cost enable the Fe3+@F,N-CD complex to be a safe and promising T1-weighted MRI contrast agent for clinical applications.


Assuntos
Carbono , Meios de Contraste , Compostos Férricos , Flúor , Imagem por Ressonância Magnética , Nanopartículas , Neoplasias Experimentais/diagnóstico por imagem , Nitrogênio , Animais , Carbono/química , Carbono/farmacologia , Meios de Contraste/química , Meios de Contraste/farmacologia , Compostos Férricos/química , Compostos Férricos/farmacologia , Flúor/química , Flúor/farmacologia , Células HeLa , Humanos , Camundongos , Camundongos Endogâmicos BALB C , Nanopartículas/química , Nanopartículas/uso terapêutico , Neoplasias Experimentais/metabolismo , Neoplasias Experimentais/patologia , Nitrogênio/química , Nitrogênio/farmacologia
9.
Anal Chem ; 91(10): 6730-6737, 2019 May 21.
Artigo em Inglês | MEDLINE | ID: mdl-31001974

RESUMO

Unveiling the synergism among multiple organelles for fully exploring the mysteries of the cell has drawn more and more attention. Herein, we developed two two-photon fluorescent bioprobes (Lyso-TA and Mito-QA), of which the conformational change triggered an "off-on" fluorescent response. Lyso-TA can real-time monitor the fusion and movement of lysosomes as well as unveil the mitophagy process with the engagement of lysosomes. Mito-QA was transformed from Lyso-TA by one-step ambient temperature reaction, visualizing the dysfunctional mitochondria through a shift from mitochondria to nucleoli. With superior two-photon absorption cross section, good biocompatibility, and greater penetration depth, two small bioprobes were both applied in in vivo bioimaging of brain tissues and zebrafish.

10.
Talanta ; 195: 158-164, 2019 Apr 01.
Artigo em Inglês | MEDLINE | ID: mdl-30625526

RESUMO

Pyrophosphate (PPi) played crucial roles in various fundamental physiological processes. Herein, a two-photon absorption (TPA) "On-Off-On" type benzoxazole-based fluorescence probe BN was designed and synthesized, which detected PPi through Cu2+ displacing method in situ system in aqueous medium. The on-off-on process of BN recognizing PPi was verified by mass spectra and theoretical calculations, which was successfully applied in TPA cells imaging.


Assuntos
Benzoxazóis/química , Complexos de Coordenação/química , Cobre/química , Difosfatos/análise , Corantes Fluorescentes/química , Difosfatos/química , Células HeLa , Humanos , Imagem Óptica , Solubilidade , Água/química
11.
Chem Commun (Camb) ; 55(10): 1450-1453, 2019 Jan 29.
Artigo em Inglês | MEDLINE | ID: mdl-30644469

RESUMO

Herein, a series of photosensitizers were constructed of α, ß and γ-isomers of terpyridine and the corresponding N-methylation derivatives. Benefiting from the tunable singlet-triplet energy gap and aggregation-induced emission characteristics, two-photon active photosensitizers L2b and L2c showed relatively strong intersystem crossing facilitating 1O2 generation and cell apoptosis with near-infrared excitation.

12.
Dalton Trans ; 48(5): 1900-1905, 2019 Feb 07.
Artigo em Inglês | MEDLINE | ID: mdl-30652713

RESUMO

In this study, by employing mixed organic ligands through rational design and metal ions as the initial reactants, a series of novel metal-organic frameworks (AHU-TW1 to 6) were synthesized by a solvothermal method. Herein, accessible Lewis base sites originating from organic ligands within MOFs act as functional sites that can interact with the analyte possessing protons and then lead to obvious variations in the fluorescence spectra. Due to their superiority, AHU-TW1, 3, 4 and 6 are able to recognize trinitrophenol (TNP) with high sensitivity and a low detection limit.

13.
Anal Chem ; 91(1): 977-982, 2019 Jan 02.
Artigo em Inglês | MEDLINE | ID: mdl-30507133

RESUMO

Visualizing and dynamic tracking lipid droplets (LDs) are of great importance to biological research. Herein, two-photon absorption fluorescent small bioprobes based on lipophilic coumarin were developed, which exhibited high selectivity toward LDs in HeLa cells. Because of good biocompatibility and excellent photostability, the probes were applied to realize specific super-resolution visualization of the intracellular LDs in HeLa cells, offering us the quantitative results of the amount and diameters of LDs as well. Furthermore, the bioprobes were capable of monitoring the movements of the LDs in real time. We believe that bioprobes would provide new avenues to designing bioimaging and biological diagnosis.

14.
J Inorg Biochem ; 192: 1-6, 2019 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-30544075

RESUMO

Compared to organotin (IV) compounds with biochemical activity, two-photon absorption (2PA) organotin (IV) complexes for targeting nuclear with anticancer activities are rarely reported. Here, two novel 2PA organotin (IV) cyano carboxylate complexes (C1Sn-1, C1Sn-2) are synthesized and characterized. The two-photon absorption cross section values (δ) in the near-infrared region are significantly enhanced for C1Sn-2 compared to C1Sn-1, thus developing for targeting nuclear by two-photon fluorescence microscopy (2PFM). C1Sn-2 could specifically target nuclear DNA in vitro. The mechanism demonstrated that there are abundant hydrogen bond interactions between hydroxy group of C1Sn-2 and DNA. The animal mode studies are first proposed that C1Sn-2 displayed a certain anti-cancer efficiency with non-significant toxicity.

15.
Inorg Chem ; 57(22): 14134-14143, 2018 Nov 19.
Artigo em Inglês | MEDLINE | ID: mdl-30376316

RESUMO

It is currently challenged that nonlinear optical (NLO) properties in the near-infrared region (NIR) of metal complexes can be tunable with an assistant ligand. Herein, the linear and nonlinear photophysical properties of the novel C^N^C cyclometalated Pt(II) complexes with different substituents as auxiliary ligands are presented. The complexes displayed intense triplet metal/ligand-to-ligand charge-transfer (3MLCT/3LLCT) and intraligand 3π, π* emission at low-temperature. The excited-state characteristics are further confirmed over the TD-DFT calculations, transient absorption, and emission lifetimes. The Pt-3 possesses a relatively high quantum yield (9.1%), a moderate triplet excited-state lifetime (5.32 µs), and a broad excited-state absorption from the visible to the near-IR region. Interestingly, it was found that Pt-3 exhibited high 2PA cross section values (σ2 up to 367 GM at 820 nm), as well as good optical limiting properties over a tunable femtosecond laser. The relationships between the structures and properties were systematically investigated on the basis of crystal structural information. Hence, cyclometalated Pt(II) complexes would become candidates for the application of the NIR NLO materials.

16.
Chem Commun (Camb) ; 54(80): 11288-11291, 2018 Oct 04.
Artigo em Inglês | MEDLINE | ID: mdl-30232472

RESUMO

We present a thiophene-based terpyridine Zn(ii) complex (namely LC) which could specifically target live cell mitochondria via binding with mitochondrial DNA (mtDNA). Due to its high biocompatibility, red emission and photo-stability, mtDNA distribution within mitochondrial cristae and inner matrix in living cells was successfully visualized using stimulated emission depletion (STED) nanoscopy with unprecedented resolution.


Assuntos
DNA Mitocondrial/análise , DNA Mitocondrial/química , Nanotecnologia , Compostos Organometálicos/química , Piridinas/química , Tiofenos/química , Zinco/química , Células HeLa , Humanos , Microscopia de Fluorescência , Estrutura Molecular
17.
ACS Appl Mater Interfaces ; 10(38): 31959-31964, 2018 Sep 26.
Artigo em Inglês | MEDLINE | ID: mdl-30130086

RESUMO

Neuronal nuclei (NeuN) protein is a key RNA-associated protein to guide the transcription of RNA and regulate mRNA splicing in neurons. However, the lack of effective labeling and tracking method has hindered the elucidation of the biological mechanism of NeuN operation in living neurons to understand correlated central nervous system disorders. Here, we report a molecular probe that can be inserted into a neighboring hydrophobic-hydrophilic region in NeuN, which upon binding becomes capable of emitting light in red region. The NeuN specificity enables the probe imaging neuronal cells in primary brain regions including hippocampus, cerebellum, midbrain, and cingulate gyrus. The probes' optical properties are such to enable stimulated emission depletion imaging showing for the first time the 3D structure of RNA tangling into NeuN in a living neuron with tens of nanometer resolution.


Assuntos
Antígenos Nucleares/metabolismo , Corantes Fluorescentes/metabolismo , Proteínas do Tecido Nervoso/metabolismo , Neurônios/patologia , Núcleo Celular/metabolismo , Núcleo Celular/patologia , Corantes Fluorescentes/química , Hipocampo/diagnóstico por imagem , Humanos , Microscopia de Fluorescência , Neurônios/citologia , Ligação Proteica , RNA/química
18.
Chem Commun (Camb) ; 54(64): 8834-8837, 2018 Aug 07.
Artigo em Inglês | MEDLINE | ID: mdl-30042986

RESUMO

The synthesis and optical properties of a novel series of disilanylene-bridged BODIPY-based D-σ-A chromophores are reported. Si-Si σ-electrons are useful and impressible for tunable optical properties. The electron-donating group facilitates enhancement of the CT nature of the excited state through σ(Si-Si) orbital, leading to the remarkable two-photon absorption cross-sections.

19.
Talanta ; 188: 178-182, 2018 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-30029361

RESUMO

A simple and sensitive probe, pyridine-based Schiff base (PBSB), is prepared based on the previous studies, which shows a rapid response to copper (II) through a fluorescence enhancement process. On association with copper (II), PBSB immediately presents a large red-shift (130 nm) in emission spectrum simultaneously accompanying with increasing emission intensity. The mechanism and binding sites of PBSB detecting copper (II) have been established by theoretical calculations and 1HNMR study, respectively. More importantly, in the complex biological system, PBSB having an excellent membrane permeability and a great photostability can visualize copper (II) in lipid droplet by bio-imaging, which display so great promising advantages in the issues causing by disorder of copper ions that could be convenient for prevention and control problems with human health and complex bio-system.

20.
Spectrochim Acta A Mol Biomol Spectrosc ; 204: 446-451, 2018 Nov 05.
Artigo em Inglês | MEDLINE | ID: mdl-29966899

RESUMO

A novel multifunctional probe, L, based on triphenylamine o-hydroxyl Schiff base was constructed for the sequential detection of Zn2+/P2O74-. Interestingly, probe L also showed two-photon fluorescent "off-on" response to Zn2+ along with a large effective two-photon absorption cross-section value of 240 GM at 720 nm, a low cytotoxic and a moderate photostability, which made L a good candidate for two-photon fluorescence microscopy imaging and monitoring the fluctuation of exogenous Zn2+.

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