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1.
Acta Pharmacol Sin ; 2024 Apr 12.
Artigo em Inglês | MEDLINE | ID: mdl-38609561

RESUMO

Proteolysis targeting chimeras (PROTACs) have emerged as revolutionary anticancer therapeutics that degrade disease-causing proteins. However, the anticancer performance of PROTACs is often impaired by their insufficient bioavailability, unsatisfactory tumor specificity and ability to induce acquired drug resistance. Herein, we propose a polymer-conjugated PROTAC prodrug platform for the tumor-targeted delivery of the most prevalent von Hippel-Lindau (VHL)- and cereblon (CRBN)-based PROTACs, as well as for the precise codelivery of a degrader and conventional small-molecule drugs. The self-assembling PROTAC prodrug nanoparticles (NPs) can specifically target and be activated inside tumor cells to release the free PROTAC for precise protein degradation. The PROTAC prodrug NPs caused more efficient regression of MDA-MB-231 breast tumors in a mouse model by degrading bromodomain-containing protein 4 (BRD4) or cyclin-dependent kinase 9 (CDK9) with decreased systemic toxicity. In addition, we demonstrated that the PROTAC prodrug NPs can serve as a versatile platform for the codelivery of a PROTAC and chemotherapeutics for enhanced anticancer efficiency and combination benefits. This study paves the way for utilizing tumor-targeted protein degradation for precise anticancer therapy and the effective combination treatment of complex diseases.

2.
Small ; 19(2): e2204864, 2023 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-36394082

RESUMO

Electrochemical activation strategy is very effective to improve the intrinsic catalytic activity of metal phosphate toward the sluggish oxygen evolution reaction (OER) for water electrolysis. However, it is still challenging to operando trace the activated reconstruction and corresponding electrocatalytic dynamic mechanisms. Herein, a constant voltage activation strategy is adopted to in situ activate Ni2 P4 O12 , in which the break of NiONi bond and dissolution of PO4 3- groups could optimize the lattice oxygen, thus reconstructing an irreversible amorphous Ni(OH)2 layer with a thickness of 1.5-3.5 nm on the surface of Ni2 P4 O12 . The heterostructure electrocatalyst can afford an excellent OER activity in alkaline media with an overpotential of 216.5 mV at 27.0 mA cm-2 . Operando X-ray absorption fine structure spectroscopy analysis and density functional theory simulations indicate that the heterostructure follows a nonconcerted proton-electron transfer mechanism for OER. This activation strategy demonstrates universality and can be used to the surface reconstruction of other metal phosphates.

3.
Anal Chem ; 94(2): 1076-1084, 2022 01 18.
Artigo em Inglês | MEDLINE | ID: mdl-34985279

RESUMO

Closely related to multiple chronic inflammation, especially type-2 diabetes (T2D), methylglyoxal (MGO) may be a potential key to visualize disease progression and treatment effects. On the other hand, lack of convenient and fast analytical methods cannot afford accurate MGO quantitative evaluation. In this work, an activatable second near-infrared region (NIR-II) fluorescent probe TDTCD was synthesized and its reaction mechanism with MGO was discussed. The desired NIR-II product preferred response solvents with small polarity. A novel activatable nanoprobe, MG-SLNP, for MGO was then constructed based on rational packaging to provide a local nonpolar microenvironment. The hydrophobic core of nanoparticles not only successfully improved the stability and water solubility but also greatly promoted the response rate while reacting with MGO. The comparison between NIR-II fluorescence and the traditional high-performance liquid chromatography method for T2D blood samples was discussed. A high-resolution viewing window, quick response, and good biocompatibility led to a satisfactory signal-to-noise ratio of MG-SLNP for real-time MGO bio-detection and imaging in vivo.


Assuntos
Nanopartículas , Aldeído Pirúvico , Corantes Fluorescentes/química , Nanopartículas/química , Imagem Óptica/métodos
4.
Analyst ; 147(13): 3065-3071, 2022 Jun 27.
Artigo em Inglês | MEDLINE | ID: mdl-35671293

RESUMO

Fluorescence imaging in the near-infrared (NIR) window has great potential for clinical diagnosis and treatment because of its deep penetration and high contrast. Here, a NIR hemicyanine-based probe (CyP) was synthesized for selective detection and imaging of Hg2+ in living cells and animals. Using the rigid xanthene structure as the electron donor, trimethylindolenine as the electron acceptor and diphenylphosphinothioic chloride as the recognition element, the probe CyP could specifically respond to Hg2+ and transform into an activated donor-π-acceptor (D-π-A) motif with a NIR emission maximum at 710 nm. Cell and animal imaging experiments showed that the probe CyP could be activated by Hg2+ and had good concentration dependence in imaging. Meanwhile, animal imaging experiments showed that the activated CyP probe exhibited a higher tissue penetration depth and spatiotemporal resolution. Thus, the probe CyP could be a useful tool for monitoring and visually evaluating Hg2+ in living systems.


Assuntos
Corantes Fluorescentes , Mercúrio , Animais , Carbocianinas/química , Corantes Fluorescentes/química , Corantes Fluorescentes/toxicidade , Imagem Óptica
5.
Anal Chem ; 93(21): 7625-7634, 2021 06 01.
Artigo em Inglês | MEDLINE | ID: mdl-34010568

RESUMO

Nitric oxide (NO)-based cancer therapy has attracted much attention in recent years owing to its broad effects on cancer. Low concentrations of NO stimulate cancer cell progression, while its higher levels induce cell apoptosis, and thus, it has motivated the development of probes for in situ NO release monitoring. In this work, a galactose-modified benzothiadiazole-based fluorescent probe (GalNONP/C) was synthesized as both a NO-responsive nanoprobe and NO prodrug carrier. The probe exhibited far-red emission in the range from 550 to 800 nm, and the response showed acidity preference. The galactose on the probe enabled selective targeting of hepatocellular carcinoma (HCC) cells by binding to the asialoglycoprotein receptor (ASGPR) on the cell surface. The probe also delivered low-molecular weight NO prodrug JS-K into cells and monitored the real-time release of the generated NO. Furthermore, in vivo NO imaging with tumor targeting was demonstrated in HCC orthotopic transplantation nude mice and liver sections. Compared with the control experiment using a probe without NO prodrug loading, higher fluorescence response of NO was detected in the cell (3.0 times) and liver slices of the HCC tumor model (2.7 times). This strategy may pave the way to develop nanoprobes for in situ NO monitoring and therapy evaluation in NO-related cancer therapy.


Assuntos
Carcinoma Hepatocelular , Neoplasias Hepáticas , Pró-Fármacos , Animais , Carcinoma Hepatocelular/tratamento farmacológico , Linhagem Celular Tumoral , Galactose , Neoplasias Hepáticas/tratamento farmacológico , Camundongos , Camundongos Nus , Óxido Nítrico
6.
Anal Chem ; 93(43): 14359-14364, 2021 11 02.
Artigo em Inglês | MEDLINE | ID: mdl-34661391

RESUMO

The analysis of ribonucleic acid (RNA) plays an important role in the early diagnosis of diseases and will greatly benefit patients with a higher cure rate. However, the low abundance of RNA in physiological environments requires ultrahigh sensitivity of a detection technology. Here, we construct a portable and smart-phone-controlled biosensing platform based on disposable organic electrochemical transistors for ultrasensitive analysis of microRNA (miRNA) biomarkers within 1 h. Due to their inherent amplification function, the devices can detect miRNA cancer biomarkers from little-volume solutions with concentrations down to 10-14 M. The devices can distinguish blood miRNA expression levels at different cancer stages using a 4T1 mouse tumor model. The technique for ultrasensitive and fast detection of RNA biomarkers with high selectivity opens a window for mobile diagnosis of various diseases with low cost.


Assuntos
Técnicas Biossensoriais , MicroRNAs , Animais , Biomarcadores Tumorais , Técnicas Eletroquímicas , Humanos , Limite de Detecção , Camundongos
7.
Small ; 17(13): e2007882, 2021 04.
Artigo em Inglês | MEDLINE | ID: mdl-33690984

RESUMO

Colorectal cancer (CRC) ranks as the third common and the fourth lethal cancer type worldwide. Immune checkpoint blockade therapy demonstrates great efficacy in a subset of metastatic CRC patients, but precise activation of the antitumor immune response at the tumor site is still challenging. Here a versatile prodrug nanoparticle for second near-infrared (NIR-II) fluorescence imaging-guided combinatory immunotherapy of CRC is reported. The prodrug nanoparticles are constructed with a polymeric oxaliplatin prodrug (PBOXA) and a donor-spacer-acceptor-spacer-donor type small molecular fluorophore TQTCD. The later displays large Stokes shift (>300 nm), fluorescence emission over 1000 nm, and excellent photothermal conversion performance for NIR-II fluorescence imaging-guided photothermal therapy (PTT). The prodrug nanoparticles show seven times higher intratumoral OXA accumulation than free oxaliplatin. TQTCD-based PTT and PBOXA-induced chemotherapy trigger immunogenic cell death of the tumor cells and elicit antitumor immune response in a spatiotemporally controllable manner. Further combination of the prodrug nanoparticle-based PTT/chemotherapy with programmed death ligand 1 blockade significantly promotes intratumoral infiltration of the cytotoxic T lymphocytes and eradicates the CRC tumors. The NIR-II fluorescence imaging-guided immunotherapy may provide a promising approach for CRC treatment.


Assuntos
Neoplasias Colorretais , Nanopartículas , Pró-Fármacos , Linhagem Celular Tumoral , Neoplasias Colorretais/tratamento farmacológico , Humanos , Imunoterapia , Imagem Óptica , Oxaliplatina , Fototerapia
8.
Chembiochem ; 22(24): 3369-3380, 2021 12 10.
Artigo em Inglês | MEDLINE | ID: mdl-34411411

RESUMO

Nanotechnology has been widely applied to the fabrication of drug delivery systems in the past decades. Recently, with the progress made in microfabrication approaches, nanorobots are steadily becoming a promising means for tumor-targeting drug delivery. In general, nanorobots can be divided into two categories: nanomotors and stimuli-responsive nanorobots. Nanomotors are nanoscale systems with the ability to convert surrounding energies into mechanical motion, whereas stimuli-responsive nanorobots are featured with activatable capacity in response to various endogenous and exogenous stimulations. In this minireview, the dynamic control of nanomotors and the rational design of stimuli-responsive nanorobots are overviewed, with particular emphasis on their contribution to tumor-targeting therapy. Moreover, challenges and perspectives associated with the future development of nanorobots are presented.


Assuntos
Antineoplásicos/farmacologia , Sistemas de Liberação de Medicamentos , Nanopartículas/química , Neoplasias/tratamento farmacológico , Antineoplásicos/química , Proliferação de Células/efeitos dos fármacos , Humanos , Nanotecnologia , Neoplasias/patologia
9.
Anal Chem ; 92(8): 5838-5845, 2020 04 21.
Artigo em Inglês | MEDLINE | ID: mdl-32237737

RESUMO

Development of probes for accurate sensing and imaging of biometals in situ is still a growing interest owing to their crucial roles in cellular metabolism, neurotransmission, and apoptosis. Among them, Zn2+ and Cu2+ are two important cooperative biometals closely related to Alzheimer's disease (AD). Herein, we developed a multifunctional probe based on self-assembling peptide nanoribbon for ratiometric sensing of Zn2+, Cu2+, or Zn2+ and Cu2+ simultaneously. Uniform peptide nanoribbon (AQZ@NR) was rationally designed by coassembling a Zn2+-specific ligand AQZ-modified peptide (AQZKL-7) with peptide KL-7. The nanoribbon further combined with Cu2+-sensitive near-infrared quantum dots (NIR QDs) and Alexa Fluor 633 as an inner reference molecule, which was endowed with the capability for ratiometric Zn2+ and Cu2+ imaging at the same time. The peptide-based probe exhibited good specificity to Zn2+ and Cu2+ without interference from other ions. Importantly, the nanoprobe was successfully applied for noninvasive Zn2+ and Cu2+ monitoring in both living cells and zebrafish via multicolor fluorescence imaging. This gives insights into the dynamic Zn2+ and Cu2+ distribution in an intracellular and in vivo mode, as well as understanding the neurotoxicity of high concentration of Zn2+ and Cu2+. Therefore, the self-assembled nanoprobe shows great promise in multiplexed detection of many other biometals and biomolecules, which will benefit the diagnosis and treatment of AD in clinical applications.


Assuntos
Metais Pesados/análise , Nanoestruturas/química , Peptídeos/química , Estrutura Molecular , Peptídeos/síntese química
10.
Bioconjug Chem ; 31(2): 404-415, 2020 02 19.
Artigo em Inglês | MEDLINE | ID: mdl-31951380

RESUMO

The importance of the immune system in cancer therapy has been reaffirmed by the success of the immune checkpoint blockade. The complex tumor microenvironment and its interaction with the immune system, however, remain mysteries. Molecular imaging may shed light on fundamental aspects of the immune response to elucidate the mechanism of cancer immunotherapy. In this review, we discuss various imaging approaches that offer in-depth insight into the tumor microenvironment, checkpoint blockade therapy, and T cell-mediated antitumor immune responses. Recent advances in the molecular imaging modalities, including magnetic resonance imaging (MRI), positron electron tomography (PET), and optical imaging (e.g., fluorescence and intravital imaging) for in situ tracking of the immune response, are discussed. It is envisaged that the integration of imaging with immunotherapy may broaden our understanding to predict a particular antitumor immune response.


Assuntos
Imagem Molecular/métodos , Neoplasias/diagnóstico por imagem , Neoplasias/terapia , Animais , Humanos , Imunidade Celular , Imunoterapia/métodos , Imageamento por Ressonância Magnética/métodos , Neoplasias/imunologia , Imagem Óptica/métodos , Tomografia por Emissão de Pósitrons/métodos , Linfócitos T/imunologia , Microambiente Tumoral
11.
Anal Chem ; 91(13): 8129-8136, 2019 07 02.
Artigo em Inglês | MEDLINE | ID: mdl-31247730

RESUMO

The variation of amyloid ß peptide (Aß) concentration and Aß aggregation are closely associated with the etiology of Alzheimer's diseases (AD). The interaction of Aß with the monosialoganglioside-rich neuronal cell membrane has been suggested to influence Aß aggregation. Therefore, studies on the mechanism of Aß and sialic acids (SA) interaction would greatly contribute to better understanding the pathogenesis of AD. Herein, we report a novel approach for Aß-SA interaction analysis and highly sensitive Aß detection by mimicing the cell surface presentation of SA clusters through engineering of SA-modified peptide nanofiber (SANF). The SANF displayed well-ordered 1D nanostructure with high density of SA on surface. Using FAM-labeled Aß fragments of Aß1-16, Aß16-23, and Aß24-40, the interaction between Aß and SA was evaluated by the fluorescence titration experiments. It was found that the order of the SA-binding affinity was Aß1-16 > Aß24-40 > Aß16-23. Importantly, the presence of full-length Aß1-40 monomer triggered a significant fluorescence enhancement due to the multivalent binding of Aß1-40 to the nanofiber. This fluorescent turn-on response showed high selectivity and sensitivity for Aß1-40 detection and the method was further used for Aß aggregation process monitoring and inhibitor screening. The results suggest the proposed strategy is promising to serve as a tool for mechanism study and the early diagnosis of Alzheimer's disease.


Assuntos
Peptídeos beta-Amiloides/análise , Glicopeptídeos/química , Ácido N-Acetilneuramínico/química , Nanofibras/química , Fragmentos de Peptídeos/análise , Doença de Alzheimer/líquido cefalorraquidiano , Doença de Alzheimer/diagnóstico , Peptídeos beta-Amiloides/líquido cefalorraquidiano , Animais , Bovinos , Humanos , Fragmentos de Peptídeos/líquido cefalorraquidiano , Agregados Proteicos , Agregação Patológica de Proteínas/líquido cefalorraquidiano , Agregação Patológica de Proteínas/diagnóstico , Espectrometria de Fluorescência
12.
Anal Chem ; 91(24): 15577-15584, 2019 12 17.
Artigo em Inglês | MEDLINE | ID: mdl-31794195

RESUMO

The accurate detection of tumorous methylglyoxal (MGO) and its detoxifier glyoxalase 1 (GLO1) in living systems is critical for understanding their roles in tumor initiation and progression. To date, the in situ fluorescence detection of endogenous MGO and GLO1 in tumor has not been reported. Herein we developed a near-infrared (NIR) fluorescent probe MEBTD to specifically detect tumorous MGO. Compared with previously reported MGO fluorescent probes, MEBTD exhibits several distinct advantages, including NIR emission, high selectivity with an MGO detection limit of 18 nM, and a 131-fold off-on ratio. The probe could sense GLO1 activity and monitor the therapeutic effect of GLO1 inhibitors by imaging tumorous MGO in a both a real-time and in situ manner, demonstrating that the biological effect of GLO1 inhibitors is dependent on the GLO1 activity. Furthermore, MEBTD enables the visualization of tumorous MGO induced by GLO1 inhibitors in vivo. To the best of our knowledge, MEBTD is the first NIR fluorescent probe for specifically imaging tumorous MGO in living animals, indicating the promising potential for tumor diagnosis and therapeutic evaluation.


Assuntos
Neoplasias da Mama/patologia , Corantes Fluorescentes/química , Raios Infravermelhos , Lactoilglutationa Liase/metabolismo , Aldeído Pirúvico/metabolismo , Animais , Apoptose , Neoplasias da Mama/tratamento farmacológico , Neoplasias da Mama/metabolismo , Proliferação de Células , Inibidores Enzimáticos/farmacologia , Feminino , Humanos , Lactoilglutationa Liase/antagonistas & inibidores , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Nus , Células Tumorais Cultivadas , Ensaios Antitumorais Modelo de Xenoenxerto
13.
Small ; 15(49): e1904397, 2019 12.
Artigo em Inglês | MEDLINE | ID: mdl-31639274

RESUMO

1D peptide nanostructures (i.e., peptide nanotubes, PNTs) exhibit tunable chemo-physical properties and functions such as improved tissue adhesion, increased cellular uptake, and elongated blood circulation. In this study, the application of PNTs as a desirable 1D template for biomineralization of Cu2-x S nanoparticles (Cu2-x S NPs, x = 1-2) is reported. Monodisperse Cu2-x S NPs are uniformly coated on the peptide nanotubes owing to the specific high binding affinity of Cu ions to the imidazole groups exposed on the surface of nanotubes. The Cu2-x S NP-coated PNTs are further covalently grafted with an oxaliplatin prodrug (Pt-CuS-PNTs) to construct a versatile nanoplatform for combination cancer therapy. Upon 808 nm laser illumination, the nanoplatform induces significant hyperthermia effect and elicits reactive oxygen species generation through electron transfer and Fenton-like reaction. It is demonstrated that the versatile nanoplatform dramatically inhibits tumor growth and lung metastasis of melanoma in a B16-F10 melanoma tumor-bearing mouse model by combined photo- and chemotherapy. This study highlights the ability of PNTs for biomineralization of metal ions and the promising potential of such nanoplatforms for cancer treatment.


Assuntos
Nanopartículas Metálicas/química , Nanopartículas/química , Nanotubos de Peptídeos/química , Nanotubos/química , Animais , Biomineralização/fisiologia , Terapia Combinada , Feminino , Melanoma/metabolismo , Melanoma Experimental/metabolismo , Camundongos , Camundongos Endogâmicos C57BL
14.
Small ; 15(22): e1900157, 2019 05.
Artigo em Inglês | MEDLINE | ID: mdl-31018037

RESUMO

Tumor metastasis is considered a major cause of cancer-related human mortalities. However, it still remains a formidable challenge in clinics. Herein, a bioinspired multivalent nanoplatform for the highly effective treatment of the metastatic melanoma is reported. The versatile nanoplatform is designed by integrating indocyanine green and a chemotherapeutic drug (7-ethyl-10-hydroxycamptothecin) into phenylboronic acid (PBA)-functionalized peptide nanotubes (termed as I/S-PPNTs). I/S-PPNTs precisely target tumor cells through multivalent interaction between PBA and overexpressed sialic acid on the tumor surface in order to achieve imaging-guided combination therapy. It is demonstrated that I/S-PPNTs are efficiently internalized by the B16-F10 melanoma cells in vitro in a PBA grafting density-dependent manner. It is further shown that I/S-PPNTs specifically accumulate and deeply penetrate into both the subcutaneous and lung metastatic B16-F10 melanoma tumors. More importantly, I/S-PPNT-mediated combination chemo- and photodynamic therapy efficiently eradicates tumor and suppresses the lung metastasis of B16-F10 melanoma in an immunocompetent C57BL/6 mouse model. The results highlight the promising potential of the multivalent peptide nanotubes for active tumor targeting and imaging-guided cancer therapy.


Assuntos
Ácido N-Acetilneuramínico/química , Nanotubos de Peptídeos/química , Animais , Ácidos Borônicos/química , Humanos , Irinotecano/química , Irinotecano/uso terapêutico , Melanoma/diagnóstico por imagem , Melanoma/tratamento farmacológico , Melanoma Experimental/diagnóstico por imagem , Melanoma Experimental/tratamento farmacológico , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Nus , Inibidores da Topoisomerase I/química , Inibidores da Topoisomerase I/uso terapêutico
15.
Anal Chem ; 90(13): 7953-7962, 2018 07 03.
Artigo em Inglês | MEDLINE | ID: mdl-29889497

RESUMO

To accurately monitor the variations of lysosomal nitric oxide (NO) under physiological condition remains a great challenge for understanding the biological function of NO. Herein, we developed a new chemotype probe, namely, MBTD, for acid-promoted and far-red fluorescence imaging of lysosomal NO in vitro and ex vivo. MBTD was rationally designed by incorporating o-phenylenediamino (OPD) moiety into the donor-acceptor-donor (D-A-D) type fluorophore based on a dual intramolecular charge transfer (ICT) mechanism. Compared to previously reported OPD-based NO probes, MBTD displays several distinct advantages including large stroke shift, huge on-off ratio with minimal autofluorescence, and high NO specificity. Particularly, MBTD exhibits an acid-promoted response to NO with high acid tolerance, which greatly improves the spatial resolution to lysosomal NO by excluding the background noise from other nonacidic organelles. Furthermore, MBTD displayed much longer-lived and more stable fluorescence emission in comparison with the commercialized NO probe. MBTD was employed for ratiometric examination of the exogenous or endogenous NO of macrophages. More importantly, MBTD was able to detect the variation of lysosomal NO level in an acute liver injury mouse model ex vivo, implying the potential of MBTD for real-time monitoring the therapeutic efficacy of drug candidates for the treatment of acute liver injury. MBTD as a novel type of NO probe might open a new avenue for precisely sensing lysosomal NO-related pathological and therapeutic process.


Assuntos
Corantes Fluorescentes/química , Lisossomos/metabolismo , Óxido Nítrico/química , Óxido Nítrico/metabolismo , Imagem Óptica/métodos , Animais , Cor , Concentração de Íons de Hidrogênio , Masculino , Camundongos , Camundongos Endogâmicos BALB C , Modelos Moleculares , Conformação Molecular , Células RAW 264.7
16.
Anal Bioanal Chem ; 410(20): 4875-4884, 2018 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-29748760

RESUMO

Cysteine (Cys) is a bithiol that plays a vital role in many physiological processes. However, it is difficult to discriminate Cys from homocysteine (Hcy) and glutathione (GSH), due to their similar chemical structures and reactivity. Herein, we have developed a polymeric nanoprobe, nanoHFA, for ratiometric, highly selective, and sensitive detection of Cys based on 7-hydroxycoumarin-3-carboxylic acid (HC) and fluorescein isothiocyanate (FITC)-acrylate (FITC-A) group-functionalized lipopolymer DSPE-PEG. The probe nanoHFA showed a strong fluorescence emission peak centered at 450 nm attributed to HC and a weak fluorescence emission peak centered at 520 nm due to the photoinduced electron transfer (PET) process of FITC induced by acrylate group. In the presence of Cys, the fluorescence signal at 520 nm could be lit up and the ratio of F520nm/F450nm showed a good linear relationship in the range of 5-60 µM with a low detection limit of 0.37 µM. The probe also displayed excellent water solubility and high selectivity to Cys over other biothiols such as Hcy and GSH. Moreover, we further used probe nanoHFA to detect Cu2+ ions in the range of 100-550 nM with a detection limit of 77 nM. The nanoprobe was successfully applied for the quantitative detection of Cys in fetal bovine serum, and fluorescent strips were developed for facile and visual detection of Cys and Cu2+ ions. Graphical abstract ᅟ.


Assuntos
Cromonas/química , Cisteína/análise , Fluoresceína-5-Isotiocianato/análogos & derivados , Corantes Fluorescentes/química , Fitas Reagentes/análise , Soro/química , Acrilatos/química , Animais , Bovinos , Colorimetria/métodos , Limite de Detecção , Espectrometria de Fluorescência/métodos
17.
Anal Chem ; 89(4): 2181-2185, 2017 02 21.
Artigo em Inglês | MEDLINE | ID: mdl-28194940

RESUMO

The rapid identification of biomacromolecule structure that has a specific association with chiral enantiomers especially from natural sources will be helpful in developing enantioselective sensor and in speeding up drug exploitation. Herein, owing to its existence also in living cells, apurinic/apyrimidinic site (AP site) was first engineered into ds-DNA duplex to explore its competence in enantiomer selectivity. An AP site-specific fluorophore was utilized as an enantioselective discrimination probe to develop a straightforward chiral sensor using natural tetrahydropalmatine (L- and D-THP) as enantiomer representatives. We found that only L-THP can efficiently replace the prebound fluorophore to cause a significant fluorescence increase due to its specific binding with the AP site (two orders magnitude higher in affinity than binding with D-THP). The AP site binding specificity of L-THP over D-THP was assessed via intrinsic fluorescence, isothermal titration calorimetry, and DNA stability. The enantioselective performance can be easily tuned by the sequences near the AP site and the number of AP sites. A single AP site provides a perfect binding pocket to differentiate the chiral atom-induced structure discrepancy. We expect that our work will inspire interest in engineering local structures into a ds-DNA duplex for developing novel enantioselective sensors.


Assuntos
Alcaloides de Berberina/química , DNA/química , Corantes Fluorescentes/química , Espectrometria de Fluorescência , Estereoisomerismo , Temperatura de Transição
18.
Anal Chem ; 89(17): 9299-9306, 2017 09 05.
Artigo em Inglês | MEDLINE | ID: mdl-28738682

RESUMO

Selective nucleotide recognition for biosensor evolution requires rational probe design toward the binding-pattern-susceptible readout but without serious poison in selectivity from the context sequences. In this work, we synthesized a dual-function (trihydroxyphenyl)porphyrin (POH3) to target the abasic site (AP site) in ds-DNA using the trihydroxyphenyl substituent and the tetrapyrrole macrocycle as the recognition unit (RU) and the fluorescent signal unit (SU), respectively. RU and SU are separated from each other but are prototropically allosteric. We found that an appropriate pH favors formation of the nonfluorescent quinine/pyrrole (O-NH) conformer of POH3. However, the complementary hydrogen bonding of RU in O-NH with the target cytosine opposite the AP site switches on the SU fluorescence through prototropic allostery toward the phenol/isopyrrole (OH-N) conformer, while the bases thymine, guanine, and adenine totally silence this allostery, suggesting a superb selectivity in single-nucleotide polymorphism (SNP) analysis. The role of the prototropic allostery in achieving such SNP selectivity is also evidenced using porphyrins with other hydroxyl substituent patterns. Because of the SU separation from RU, SU is not directly involved in the interaction with the AP site, and thus, the turn-on selectivity is also realized for DNA with flanking guanine, the most easily oxidized base in DNA. This tolerance to the flanking base identity has seldom been achieved in previous studies. Additionally, other DNA structures cannot bring this allostery, indicating that the combination recipe of the AP site design and the prototropically allosteric probe will find wide applications in DNA-based sensors.


Assuntos
Sítio Alostérico , Sondas de DNA/normas , DNA/química , Sequência de Bases , Conformação de Ácido Nucleico , Polimorfismo de Nucleotídeo Único , Porfirinas/química , Sensibilidade e Especificidade
19.
Langmuir ; 33(13): 3287-3295, 2017 04 04.
Artigo em Inglês | MEDLINE | ID: mdl-28345349

RESUMO

In this study, a dual-emission fluorescence resonance energy transfer (FRET) polymeric nanoprobe by single-wavelength excitation was developed for sensitive and selective hydrogen peroxide (H2O2) detection. Polymeric nanoprobe was prepared by simple self-assembly of functional lipopolymers, which were 4-carboxy-3-fluorophenylboronic acid (FPBA)-modified DSPE-PEG (DSPE-PEG-FPBA) and 7-hydroxycoumarin (HC)-conjugated DSPE-PEG (DSPE-PEG-HC). Subsequent binding of alizarin red S (ARS) to FPBA endowed the nanoprobe with a new fluorescence emission peak at around 600 nm. Because of the perfect match of the fluorescence emission spectra of HC with the absorbance spectra of ARS-FPBA, FRET was achieved between them. The sensing strategy for H2O2 was based on H2O2-induced deboronation reaction and boronic acid-mediated ARS fluorescence. Interaction between phenylboronic acid and ARS was revisited herein and it was found that electron-donating or -withdrawing group on phenylboronic acid (PBA) has significant influence on the fluorescence property of ARS, which enabled sensitive and selective H2O2 sensing. The nanoprobe displayed two well-separated emission bands (150 nm), providing high specificity and sensitivity for ratiometric detection of H2O2. Further application was exploited for the determination of glucose and the results demonstrated that the proposed strategy showed ratiometric response capability for glucose detection. The current method does not involve complicated organic synthesis and opens a new avenue for the construction of multifunctional polymeric fluorescent nanoprobe.

20.
Small ; 12(4): 488-98, 2016 Jan 27.
Artigo em Inglês | MEDLINE | ID: mdl-26662850

RESUMO

Conventional chemotherapy shows moderate efficiency against metastatic cancer since it targets only part of the mechanisms regulating tumor growth and metastasis. Here, gold nanorod (GNR)-based host-guest nanoplatforms loaded with docetaxel (DTX) and small interfering RNA (siRNA)-p65 (referred to as DTX-loaded GNR (GDTX)/p65) for chemo-, RNA interference (RNAi), and photothermal ablation (PTA) cooperative treatment of metastatic breast cancer are reported. To prepare the nanoplatform, GNRs are first coated with cyclodextrin (CD)-grafted polyethylenimine (PEI) and then loaded with DTX and siRNA through host-guest interaction with CD and electrostatic interaction with PEI, respectively. Upon near-infrared laser irradiation, GNRs generate a significant hyperthermia effect to trigger siRNA and DTX release. DTX reduces tumor growth by inhibiting mitosis of cancer cells. Meanwhile, siRNA-p65 suppresses lung metastasis and proliferation of cancer cells by blocking the nuclear factor kappa B (NF-κB) pathway and downregulating the downstream genes matrix metalloproteinase-9 (MMP-9) and B cell lymphoma-2 (Bcl-2). It is demonstrated that GDTX/p65 in combination with laser irradiation significantly inhibits the growth and lung metastasis of 4T1 breast tumors. The antitumor results suggest promising potential of the host-guest nanoplatform for combinational treatment of metastatic cancer by using RNAi, chemotherapy, and PTA.


Assuntos
Neoplasias da Mama/patologia , Neoplasias Pulmonares/tratamento farmacológico , Neoplasias Pulmonares/secundário , Neoplasias Mamárias Experimentais/patologia , Nanotubos/química , RNA Interferente Pequeno/metabolismo , Taxoides/uso terapêutico , Animais , Antineoplásicos/farmacologia , Western Blotting , Morte Celular/efeitos dos fármacos , Linhagem Celular Tumoral , Docetaxel , Endocitose , Feminino , Técnicas de Silenciamento de Genes , Ouro , Humanos , Camundongos , Nanotubos/ultraestrutura , Espectrofotometria Ultravioleta , Eletricidade Estática , Temperatura , Fatores de Tempo
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