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1.
J Chromatogr A ; : 460898, 2020 Jan 18.
Artigo em Inglês | MEDLINE | ID: mdl-32044125

RESUMO

A functionalized magnetic covalent organic framework containing the nitro groups (Fe3O4@COF-(NO2)2) with core-shell structure was synthesized for magnetic solid phase extraction (MSPE) of six neonicotinoid insecticides residue in vegetable samples. The structure of Fe3O4@COF-(NO2)2 was investigated by various characterization techniques. The Fe3O4@COF-(NO2)2 exhibits the excellent thermal and chemical stability, high surface area (254.72 m2 g-1), total pore volume (0.19 cm3 g-1), high magnetic responsivity (27.7 emu g-1), which can be used as an ideal adsorbent for rapid isolation and enrichment of target analytes. A sensitive method was developed by using Fe3O4@COF-(NO2)2-based MSPE coupled with HPLC with UV detection. It offered good linearity within the range of 0.1-30 ng mL-1, low limits of detection (S/N = 3) of 0.02-0.05 ng mL-1. Furthermore, high enrichment factors of 170-250 for six neonicotinoid insecticides were obtained. The applicability of Fe3O4@COF-(NO2)2 is demonstrated for measuring trace neonicotinoid residues in vegetable samples with satisfactory recoveries, which ranged from 77.5 to 110.2%. The results indicated that the Fe3O4@COF-(NO2)2 microspheres offer great potential for efficient extraction of neonicotinoid insecticides from complex samples.

2.
Sci Rep ; 10(1): 71, 2020 Jan 09.
Artigo em Inglês | MEDLINE | ID: mdl-31919391

RESUMO

The development of methods to effectively capture N-glycopeptides from the complex biological samples is crucial to N-glycoproteome profiling. Herein, the hydrophilic chitosan-functionalized magnetic graphene nanocomposites (denoted as Fe3O4-GO@PDA-Chitosan) were designed and synthesized via a simple two-step modification (dopamine self-polymerization and Michael addition). The Fe3O4-GO@PDA-Chitosan nanocomposites exhibited good performances with low detection limit (0.4 fmol·µL-1), good selectivity (mixture of bovine serum albumin and horseradish peroxidase tryptic digests at a molar ration of 10:1), good repeatability (4 times), high binding capacity (75 mg·g-1). Moreover, Fe3O4-GO@PDA-Chitosan nanocomposites were further utilized to selectively enrich glycopeptides from human renal mesangial cell (HRMC, 200 µg) tryptic digest, and 393 N-linked glycopeptides, representing 195 different glycoproteins and 458 glycosylation sites were identified. This study provides a feasible strategy for the surface functionalized novel materials for isolation and enrichment of N-glycopeptides.

3.
Small ; : e1904199, 2020 Jan 23.
Artigo em Inglês | MEDLINE | ID: mdl-31971662

RESUMO

The selective and highly efficient capture of circulating tumor cells (CTCs) from blood and their subsequent release without damage are very important for the early diagnosis of tumors and for understanding the mechanism of metastasis. Herein, a universal strategy is proposed for the fabrication of an antibody-free hydrogel that has a synergistic effect by featuring microinterfaces obtained by cell imprinting and molecular recognition conferred by boronate affinity. With this artificial antibody, highly efficient capture of human hepatocarcinoma SMMC-7721 cells is achieved: as many as 90.3 ± 1.4% (n = 3) cells are captured when 1 × 105 SMMC-7721 cells are incubated on a 4.5 cm2 hydrogel, and 99% of these captured cells are subsequently released without any loss of proliferation ability. In the presence of 1000 times as many nontarget cells, namely, leukaemia Jurkat cells, the SMMC-7721 cells can be captured with an enrichment factor as high as 13.5 ± 3.2 (n = 3), demonstrating the superior selectivity of the artificial antibody for the capture of the targeted CTCs. Most importantly, the SMMC-7721 cells can be successfully captured even when spiked into whole blood, indicating the great promise of this approach for the further molecular characterization of CTCs.

4.
Talanta ; 210: 120632, 2020 Apr 01.
Artigo em Inglês | MEDLINE | ID: mdl-31987190

RESUMO

An efficient and selective glycoproteins enrichment platform is essential to glycoprotein biomarkers in early clinic diagnostics. In this work, the poly (ethylene glycol) methyl ether methacrylate (PEGMA) and 4-vinylphenylboronic acid (VPBA) copolymer brushes grafted magnetic carbon nanotubes composite MCNTs@p (PEGMA-co-VPBA) was prepared by surface-initiated atom transfer polymerization and applied for the selective enrichment of glycoproteins from the complex biological samples. The as-prepared MCNTs@p (PEGMA-co-VPBA) nanocomposite was characterized by Fourier transform-infrared spectroscopy (FTIR), transmission electron microscopy (TEM), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS) and vibrating sample magnetometry (VSM). The MCNTs@p (PEGMA-co-VPBA) can recognize and bind specifically for glycoproteins via strong boronate affinity and excellent hydrophilicity and shows a really low non-specificity adsorption capability for non-glycoproteins. The adsorption capacity of MCNTs@p (PEGMA-co-VPBA) towards glycoproteins transferrin (Trf), horseradish peroxidase (HRP), and non-glycoproteins cytochrome c (Cyt C), lysozyme (Lyz) is 253.3 mg g-1, 51.1 mg g-1, 13.9 mg g-1 and 14.5 mg g-1, respectively. Furthermore, MCNTs@p (PEGMA-co-VPBA) can be applied to extract glycoproteins directly from egg white samples. These results demonstrated that MCNTs@p (PEGMA-co-VPBA) could be a potential affinity adsorbent in glycoprotein enrichment.

5.
Talanta ; 209: 120552, 2020 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-31892096

RESUMO

Currently, the nanocomposites based on silicon nanoparticles (SiNPs) are usually limited to a single therapeutic modality, and the design of the SiNPs nanohybrids with multi-modal synergistic therapeutic functions is still worth being explored to achieve more effective treatment. Herein, we used mesoporous silica nanoparticle (MSN) as a nanoplatform, SiNPs and the photosensitizer 5,10,15,20-tetrakis (1-methyl 4-pyridinio) porphyrin tetra (p-toluenesulfonate) (TMPyP) were first embedded in the MSN and was further modified with folic acid (FA) to obtain the mesoporous silica nanocomposite (MSN@SiNPs@TMPyP-FA) for targeted two-photon-excited fluorescence imaging-guided photodynamic therapy (PDT) and chemotherapy. The embedded TMPyP could generate singlet oxygen to perform PDT under light irradiation, meanwhile the anticancer drugs doxorubicin (DOX) could be loaded for chemotherapy. Moreover, due to the two-photon excited fluorescence of SiNPs, the nanocomposite successfully achieved targeted two-photon fluorescence cellular imaging at the near-infrared (NIR) laser excitation, which could effectively avoid the interference of biological auto-fluorescence. And in vitro cytotoxicity assays revealed that the synergistic therapy combining PDT and chemotherapy exhibited high therapeutic efficacy for cancer cells.

6.
Anal Chem ; 92(1): 1097-1105, 2020 Jan 07.
Artigo em Inglês | MEDLINE | ID: mdl-31814401

RESUMO

Chemical cross-linking combined with mass spectrometry (CXMS) has emerged as a powerful tool to study protein structure, conformation, and protein-protein interactions (PPIs). Until now, most cross-linked peptides were generated by using commercial cross-linkers, such as DSS, BS3, and DSSO, which react with the primary amino groups of the lysine residues of proteins. However, trypsin, the most commonly used proteolytic enzyme, cannot cleave the C-terminus of a linked lysine, making the obtained cross-linked peptides longer than common peptides and unfavorable for MS identification and data searching. Herein, we propose an in situ sequential digestion strategy using enzymes with distinct cleavage specificity, named as smart cutter, to generate cross-linked peptides with suitable length so that the identification coverage could improve. Through the application of such a strategy to DSS cross-linked E. coli lysates, additional cross-linked sites (1.3-fold increase) obtained in comparison with those obtained by trypsin-trypsin digestion (2879 vs 1255). Among the different digestion combinations, AspN-trypsin performed the best, with 64% (673/1059) of the cross-linked sites complementary to trypsin-trypsin digestion, which is beneficial to ensure the depth for studying protein structure and PPIs. Taking the 60 kDa chaperonin protein as an example, more than twice the cross-linked sites (30 vs 14) were identified to enrich the protein structure information. In addition, compared to the published protein interaction network for E. coli ( http://www.bacteriome.org ), 91 potential PPIs were discovered with our strategy, of which 65 have not covered by trypsin-trypsin digestion. Therefore, these results illustrate the great significance of smart-cutter-based CXMS for the revelation of protein structure as well as finding new PPIs.

7.
J Chromatogr A ; 1609: 460496, 2020 Jan 04.
Artigo em Inglês | MEDLINE | ID: mdl-31519406

RESUMO

Velvet antlers (VA) have been used as medicines and nutraceuticals for over 2000 years. Meanwhile, deer antlers are the only mammalian organs that can fully regenerate after annual shedding. The antler formation and regeneration rely on the stem cells resident in antlerogenic periosteum (AP), transplantation of which can induce ectopic antler formation. Here, a comprehensive quantitative proteomic analysis of antlerogenic periosteal cells (AP cells), compared with the adjacent facial periosteal cells (FP cells), was carried out, from both extracellular and intracellular perspectives. In this study, the stable isotope labeling by amino acids in cell culture (SILAC) was applied to ensure the precision of quantification. Then, the protein equalization strategy and reverse-phase liquid chromatography (RPLC) separation in high pH were utilized to improve the depth of proteome profiling. Proteomics analysis of the conditioned media (CM) from AP and FP cells showed that significantly over-expressed extracellular proteins in AP cells were involved in cell proliferation, angiogenesis and neurogenesis. Combining the extracellular and intracellular proteomes, we found several potential secreted proteins might regulate antler formation and regeneration, such as SFRP4 and LUM. These results provide new insight into the underlying mechanism of antler formation and regeneration.

8.
Anal Chem ; 92(1): 567-572, 2020 Jan 07.
Artigo em Inglês | MEDLINE | ID: mdl-31846294

RESUMO

Protein N-termini and their modifications not only represent different protein isoforms but also relate to the functional annotation and proteolytic activities. Currently, negative selection methods, such as terminal amine isotopic labeling of substrates (TAILS), are the most popular strategy to analyze the protein N-terminome, in which dimethylation or acetylation modification is commonly used to block the free amines of proteome samples. However, after tryptic digestion, the generated long peptides, caused by the missing cleavage of blocked lysine, could hardly be identified by MS, which hindered the deep-coverage analysis of N-terminome. Herein, to solve this problem, we developed an approach, named terminal amine guanidination of substrates (TAGS). 1H-Pyrazole-1-carboxamidine was used to effectively guanidinate lysine ε-amines and N-terminal α-amines, followed by tryptic digestion to generate N-terminal peptides without free amines and internal peptides with free amines. Then, the internal peptides with free amines were removed by hyperbranched polyglycerol-aldehyde polymers (HPG-ALDs) to achieve the negative enrichment of N-terminome. By TAGS, not only the cleavage rate of blocked lysine could be improved, but also the ionization efficiency of tryptic peptides was increased. In comparison, 1814 and 1620 protein N-termini were, respectively, identified by TAGS and TAILS in Saccharomyces cerevisiae (S. cerevisiae). Among them, 1012 N-termini were uniquely identified in TAGS. Furthermore, by the combination of TAGS and the stable isotope labeling with amino acids in cell culture (SILAC)/label-free quantitative method, we not only identified the known N-terminal cleavage fragment of gasdermin D but also identified some new cleavage sites during Val-boroPro-induced pyroptosis. All these results demonstrated that our developed approach, TAGS, might be of great promise for the comprehensive analysis of N-terminome and beneficial for promoting the identification of protein isoforms and studying in-depth the proteolytic activity of proteins.

9.
J Sep Sci ; 2019 Nov 30.
Artigo em Inglês | MEDLINE | ID: mdl-31785058

RESUMO

We present a facile strategy to prepare the molecularly imprinted polymers layer on the surface of Fe3 O4 nanoparticles with core-shell structure via sol-gel condensation for recognition and enrichment of triclosan. The Fe3 O4 nanoparticles were first synthesized by a solvothermal method. Then, template triclosan was self-assembled with the functional monomer 3-aminopropyltriethoxysilane on the silica-coated Fe3 O4 nanoparticles in the presence of ethanol and water. Finally, the molecularly imprinted polymers were formed on the surface of silica-coated Fe3 O4 nanoparticles to obtain the product. The morphology, magnetic susceptibility, adsorption, and recognition property of magnetic molecularly imprinted polymers were characterized using transmission electron microscopy, Fourier transform infrared spectroscopy, X-ray diffractometry, vibrating sample magnetometry, and re-binding experiments. The magnetic molecularly imprinted polymers showed binding sites with good accessibility, fast adsorption rate, and high adsorption capacity (218.34 µg/g) to triclosan. The selectivity of magnetic molecularly imprinted polymers was evaluated by the rebinding capability of triclosan and two other structural analogues (phenol and p-chlorophenol) in a mixed solution and good selectivity with an imprinting factor of 2.46 was obtained. The application of triclosan removal in environmental samples was demonstrated.

10.
J Chromatogr A ; : 460754, 2019 Nov 30.
Artigo em Inglês | MEDLINE | ID: mdl-31813565

RESUMO

Biomedical sciences, and in particular disease biomarker research, demand highly selective and efficient glycoproteins/peptides enrichment platforms. In this work, a facile strategy to prepare hydrophilic maltose-functionalized magnetic metal-organic framework loaded with Au nanoparticles (denoted as magMOF@Au-maltose) for highly efficient enrichment of N-linked glycopeptides. In brief, carboxyl-functional Fe3O4 nanospheres were firstly coated with a Zr-based MOF shell, the resulting MOF was then loaded with Au nanoparticles in situ and then modified with thiol-functional maltose via Au-S bonds to obtain magMOF@Au-maltose with core-shell structure. The physical property and adsorption of magMOF@Au-maltose to glycopeptides were investigated. The results showed magMOF@Au-maltose possessing the outstanding performance in glycopeptides enrichment with high selectivity (1:200, mass ratio of horseradish peroxidase to bovine serum albumin digest), a low limit of detection (10 fmol), a high recovery (over 83.3%), and a large binding capacity (83 µg•mg-1). The magMOF@Au-maltose nanocomposite can enrich 24 and 32 glycopeptides from tryptic HRP and human IgG digests, respectively. Moreover, the nanocomposite was applied to the selective enrichment of glycopeptides from the complex biological samples and a total of 123 unique N-glycosylation sites were identified from 113 glycopeptides in 1 µL of human serum, which were assigned to 46 different glycoproteins. These results showed the promising application of magMOF@Au-maltose in the detection and identification of low-abundance N-linked glycopeptides in complex biological samples.

11.
Anal Chem ; 91(23): 14860-14864, 2019 Dec 03.
Artigo em Inglês | MEDLINE | ID: mdl-31668058

RESUMO

Protein persulfidation is one of the most important oxidative translational modifications and plays vital roles in various important biological processes. However, the proteome-wide identification of persulfidation sites is a great challenge because of the difficulties in accurately differentiating persulfide groups with disulfide and thiol groups in proteins as well as the extremely low abundance of persulfidated peptides. By current approaches, the persulfidated peptides were often identified by the cleavage of their persulfide groups by reductants prior to MS analysis; therefore, it would bring about a false positive identification and was unable to identify persulfidation sites accurately for a single peptide with multiple cysteine residues. In this study, a novel strategy for the site-specific quantification of persulfidome (SSQPer) was developed. By this strategy, the persulfidated proteins were first labeled with cleavable isotope-coded affinity tag (c-ICAT) reagents. After digestion, the labeled persulfidated peptides were selectively enriched with streptavidin beads and fractionated by strong cation exchange chromatography, followed by LC-MS/MS identification. To evaluate the performance of SSQPer, the persulfidated BSA digests with 20 persulfidation sites identified were used to spike HeLa cell digests with mass ratios of 1:100 and 1:1000, and 16 and 13 persulfidated sites were respectively identified. We applied SSQPer to the site-specific quantification of persulfidome in the epithelial-mesenchymal transition (EMT) process, and 226 endogenous persulfidation sites were identified, of which 74.3% were newly discovered. All of these results demonstrated that the SSQPer strategy would provide a promising tool to profile the site-specific persulfidome and pave the way for future investigation to expand our knowledge of persulfidation.

12.
Se Pu ; 37(8): 836-844, 2019 Aug 08.
Artigo em Chinês | MEDLINE | ID: mdl-31642254

RESUMO

Protein persulfidation is an important oxidative translational modification which plays vital roles in many important processes including cellular senescence, endoplasmic reticulum stress, vasorelaxation, and apoptosis. The proteome-wide analysis of persulfidation is of great importance; therefore, this study combines filter-aided sample preparation with an iodoacetic acid functionalized polyamidoamine dendrimer to enrich persulfidated peptides (denoted as filter-aided dendrimer enrichment strategy, FADE). To evaluate the performance of this strategy, the synthetic persulfidated standard peptide was spiked into bovine serum albumin (BSA) digests at a mass ratio of 1:100, and was successfully identified by FADE. Moreover, in combination with stable isotope labelling by amino acids in cell culture technology, the FADE strategy was applied to enrich persulfidated peptides from NaHS-stimulated SHSY5Y cells over a concentration gradient, resulting in the identification of 163 persulfidated peptides. Bioinformatic analysis indicated that persulfidation might play important roles in the central nervous system.


Assuntos
Dendrímeros , Ácido Iodoacético/química , Peptídeos/química , Animais , Bovinos , Proteoma , Soroalbumina Bovina
13.
J Sep Sci ; 42(23): 3521-3527, 2019 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-31560415

RESUMO

Cetyltrimethyl ammonium bromide-modified attapulgite was prepared and utilized as a novel sorbent in a simple solid-phase extraction method for the determination of vitamin A in blood serum. Several factors affecting extraction efficiency were systematically optimized, including the sampling solvent and its volume, as well as the elution solvent and its volume. Under the optimal solid-phase extraction conditions, the adsorption capacity of vitamin A was as high as 28 mg/g according to the Langmuir isotherm model. Based on the developed solid-phase extraction method, the level of vitamin A in 200 µL blood serum sample could be accurately determined by high-performance liquid chromatography. The recoveries of vitamin A spiked in 10% v/v methanol aqueous solutions were in the range of 86.9-92.8%, with the relative standard deviations not more than 8.1%. The method was applied to the determination of vitamin A in serum samples from 20 pregnant women. Compared with the previously reported solid-phase extraction methods for determination of vitamin A in serum, our developed cetyltrimethyl ammonium bromide-modified attapulgite-based solid-phase extraction method used lower serum volume, omitted extra steps (i.e. evaporation and re-dissolution), and eliminated internal standard. The results were promising for it to be used in routine monitoring during pregnancy.

14.
Anal Chem ; 91(20): 12696-12703, 2019 Oct 15.
Artigo em Inglês | MEDLINE | ID: mdl-31532634

RESUMO

Nanocarriers with both targeting ability and stable loading of drugs can more effectively deliver drugs to precise tumor sites for therapeutic effects. Accordingly, we have rationally designed fluorescent molecularly imprinted polymer nanoparticles (FMIPs), which use N-terminal epitope of P32 membrane protein as the primary template and doxorubicin (DOX) as the secondary template. The DOX imprinted cavity can stably carry the drug and the epitope-imprinted cavity allows FMIPs to actively recognize the P32-positive 4T1 cancer cells. The targeted therapeutic effect of DOX-loaded FMIPs (FMIPs@DOX) is investigated in vitro and in vivo. The FMIPs@DOX only causes apoptosis in 4T1 cancer cells compared to C8161 cells (expressing low level of P32). In addition, highly effective inhibition of 4T1 malignant breast tumors using FMIPs@DOX is achieved in the model of tumor-bearing mice. Importantly, the antitumor effect achieved by intravenous injection of FMIPs@DOX is almost identical to that by intratumoral injection. Furthermore, the FMIPs can serve as a targeted fluorescence imaging agent due to the high specificity of the epitope-imprinted cavity and the stable fluorescence of the embedded silicon nanoparticles. These results demonstrate the effectiveness of the FMIPs for active targeted drug delivery and imaging. Furthermore, the FMIPs provide a direction for drug-loaded nanocarrier.

15.
Nanoscale ; 11(36): 17018-17030, 2019 Sep 28.
Artigo em Inglês | MEDLINE | ID: mdl-31502627

RESUMO

Targeting is vital for precise positioning and efficient therapy, and integrated platforms for diagnosis and therapy have attracted more and more attention. Herein, we established dual-template molecularly imprinted polymer (MIP) coated fluorescent silicon nanoparticles (Si NPs) by using the linear peptide of the extracellular region of human epidermal growth factor receptor-2 (HER2) and adopting doxorubicin (DOX) as templates for targeted imaging and targeted therapy. Benefiting from the epitope imprinting approach, the imprinted sites generated by peptides on the MIP surface can be employed for recognizing the corresponding protein, which allowed the MIP to specifically and actively target HER2-positive breast cancer cells. Because of its ability to identify breast cancer cells, the MIP was applied for targeted fluorescence imaging by taking advantage of the excellent fluorescence properties of Si NPs, and the DOX-loaded MIP (MIP@DOX) can act as a therapeutic probe to effectively target and kill breast cancer cells. In fluorescence images, the targeting of the MIP promoted more uptake of the nanoparticles by cells than the non-imprinted polymer (NIP), so HER2-positive breast cancer cells incubated with the MIP exhibited stronger fluorescence, and there was no significant difference in fluorescence when HER2-negative cells and normal cells were respectively hatched with the MIP and NIP. Importantly, the cell viability was evaluated to demonstrate targeted accumulation and therapy of MIP@DOX for breast cancer cells. The nanoplatform for diagnosis and therapy combined the high sensitivity of fluorescence with the high selectivity of the molecular imprinting technique, which holds vital potential in targeted imaging and targeted therapy in vitro.

16.
ACS Appl Mater Interfaces ; 11(35): 32431-32440, 2019 Sep 04.
Artigo em Inglês | MEDLINE | ID: mdl-31393695

RESUMO

Molecularly imprinted polymers were commonly used for drug delivery. However, single-template molecularly imprinted polymers often fail to achieve both drug delivery and precise targeting. To address this issue, a dual-template molecularly imprinted polymer nanoparticle used for targeted diagnosis and drug delivery for pancreatic cancer BxPC-3 cells (FH-MIPNPs) was prepared. In the FH-MIPNPs, the 71-80 peptide of human fibroblast growth-factor-inducible 14 modified with glucose (Glu-FH) and bleomycin (BLM) were used as templates simultaneously, so that the FH-MIPNPs could load BLM and bind to the BxPC-3 cells, which overexpress human fibroblast growth-factor-inducible 14 (FN14). Targeted imaging experiments in vitro show that the FH-MIPNPs could specifically target BxPC-3 cells and that there is no targeting effect on cells without expression of FN14. In vivo antitumor experiment results demonstrated that the FH-MIPNP-loaded BLM (FH-MIPNPs/BLM) could inhibit the growth of xenografts tumor of BxPC-3 (tumor volume increased to 1.05×), which shows that FH-MIPNPs/BLM had obvious targeted therapeutic effect compared to the other three control groups of BLM, FH-NIPNPs/BLM, and physiological saline (tumor volume increased to 1.5×, 1.6×, and 2.4×, respectively). What is more, FH-MIPNPs have low biotoxicity through toxicity experiments in vitro and in vivo, which is favorable toward making molecularly imprinted polymers an effective platform for tumor-targeted imaging and therapy.


Assuntos
Sistemas de Liberação de Medicamentos , Epitopos , Nanopartículas , Imagem Óptica , Neoplasias Pancreáticas , Peptídeos , Receptor de TWEAK/química , Animais , Linhagem Celular Tumoral , Epitopos/química , Epitopos/farmacologia , Humanos , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Nus , Impressão Molecular , Nanopartículas/química , Nanopartículas/uso terapêutico , Neoplasias Pancreáticas/diagnóstico por imagem , Neoplasias Pancreáticas/metabolismo , Neoplasias Pancreáticas/patologia , Peptídeos/química , Peptídeos/farmacologia
17.
ACS Omega ; 4(5): 8953-8959, 2019 May 31.
Artigo em Inglês | MEDLINE | ID: mdl-31459983

RESUMO

The method capable of simultaneously detecting multiple target bacterial pathogens is necessary and of great interest. In this research, we demonstrated our initial effort to simultaneously detect seven common foodborne bacteria by developing a straightforward upconversion fluorescence sensing approach. The fluorescent nanosensor was constructed from a designed guanidine-functionalized upconversion fluorescent nanoparticles (UCNPs@GDN), tannic acid, and hydrogen peroxide (HP) and could quantify pathogenic bacteria in a nonspecific manner because the luminescence of the upconversion fluorescent nanoparticle was effectively strengthened in the presence of bacteria. When the developed nanosensor was applied to quantify multiple bacteria including Escherichia coli, Salmonella, Cronobacter sakazakii, Shigella flexneri, Vibrio parahaemolyticus, Staphylococcus aureus, and Listeria monocytogenes, a linear range of 103 to 108 cfu mL-1 and a detection limit of 1.30 × 102 cfu mL-1 have been obtained for the seven model mixture bacteria. In addition, the similar linear range and detection limit were also obtained for the detection of single bacteria. The present approach also exhibited acceptable recovery values ranging from 70.0 to 118.2% for bacteria in real samples (water, milk, and beef). All these results suggested that the guanidine-functionalized upconversion fluorescent nanosensor could be considered as a promising candidate for the rapid detection and surveillance of microbial pollutants in food and water.

18.
ACS Appl Mater Interfaces ; 11(37): 34268-34281, 2019 Sep 18.
Artigo em Inglês | MEDLINE | ID: mdl-31454217

RESUMO

A multifunctional diagnosis and treatment integration platform is crucial in cancer treatments. Here, we show that by integrating Gd-doped silicon nanoparticles (Si-Gd NPs), chlorine e6 (Ce6), doxorubicin (DOX), zeolitic imidazolate framework-8 (ZIF-8), poly(2-(diethylamino)ethyl methacrylate) polymers (HOOC-PDMAEMA-SH), and folic acid-poly(ethylene glycol)-maleimide (MaL-PEG-FA) into one single nanoplatform by a self-assembly method, novel multifunctional MOFs (named FZIF-8/DOX-PD-FA) are synthesized with great biocompatibility and tumor targeting as well as pH responsiveness and no drug leakage for drug delivery. In the design, Si-Gd NPs and Ce6 embedded in the nanocomposites are used for magnetic resonance and fluorescence dual-modal imaging, respectively. DOX loaded by the FZIF-8/DOX-PD-FA porous structure is used for chemotherapy, while Ce6 is excited by near-infrared radiation (NIR) for photodynamic therapy. In addition, the pH-responsive ability of HOOC-PDMAEMA-SH to effectively prevent drug leakage is demonstrated by drug release studies in vitro. From the results of confocal microscopy imaging in vitro and fluorescence/magnetic resonance imaging in vivo, FZIF-8/DOX-PD-FA showed a targeting effect on MCF-7 cancer cells. More importantly, the results of treatment experiments on tumor-bearing mice showed that the tumor volume of the FZIF-8/DOX-PD-FA + NIR group is decreased the most compared to the original volume. Owing to the unique dual-modal imaging capability and excellent chemo-/photodynamic combinational cancer therapy effect, the present hybrid nanocarrier provides a new research platform for a new generation of theranostic nanoparticles.

19.
Adv Mater ; 31(50): e1902048, 2019 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-31423663

RESUMO

Epitope imprinting is a promising tool to generate antibody-like specific recognition sites. Recently, because of the ease of obtaining templates, the flexibility in selecting monomers, their resistance to harsh environments, and the high specificity toward targets, epitope-imprinted materials have attracted much attention in various fields, such as bioanalysis, clinical therapy, and pharmacy. Here, the discussion is focused on the current representative epitope imprinting technologies, including epitope bulk imprinting and epitope surface imprinting. Moreover, the application of epitope-imprinted materials to the recognition of peptides, proteins, and cells is reviewed. Finally, the remaining challenges arising from the intrinsic properties of epitope imprinting are discussed, and future development in the field is prospected.

20.
J Chromatogr A ; 1602: 168-177, 2019 Sep 27.
Artigo em Inglês | MEDLINE | ID: mdl-31303311

RESUMO

In this work, we presented the preparation of magnetic carbon nanotubes (MCNTs) functionalized with molecularly imprinted polymers (MIPs) for effective removal of aristolochic acid I (AAI) in traditional Chinese medicine (TCM). MCNTs@AAI-MIPs was obtained via a facile and environmental friendly sol-gel process. Firstly, MCNTs were synthesized by a solvothermal method. Then, the template molecules were self-assembled with the functional monomer phenyltrimethoxysilane (PTMOS) in the presence of ethanol and water. Finally, AAI-MIPs film was coated on the MCNTs to obtain product MCNTs@AAI-MIPs using tetraethyl-orthosilicate (TEOS) as cross-linker. The morphology and structure of prepared MIPs were characterized by Fourier transform infrared spectroscopy (FT-IR), transmission electron microscopy (TEM), X-ray diffraction (XRD), nitrogen gas adsorption and vibrating sample magnetometer (VSM). The adsorption properties were demonstrated by kinetic, isothermal and selective adsorption experiments. The results showed that the imprinted nanocomposites exhibited fast separation rate (10 s), high adsorption capacity (18.54 µg∙mg-1), short kinetic equilibrium time (15 min), and good selectivity to template molecule with imprinting factor (IF) of 3.17. A regression equation (y=57294x-4734.1) with good linearity was obtained in the concentration range of 0.1-200 µg∙mg-1 for AAI with a correlation coefficient (R2) of 0.9998. The limit of detection (LOD, S/N=3) was 0.034 µg∙mg-1. Moreover, high recoveries ranged from 80% to 110% (RSD=3.27%-8.16%) were received in spiked TCM samples. The results suggested that the proposed MCNTs@AAI-MIPs could efficiently and specifically capture AAI from an actual complex TCM samples.


Assuntos
Ácidos Aristolóquicos/isolamento & purificação , Magnetismo , Impressão Molecular/métodos , Nanotubos de Carbono/química , Polímeros/química , Adsorção , Cinética , Nanotubos de Carbono/ultraestrutura , Nitrogênio/química , Espectroscopia de Infravermelho com Transformada de Fourier , Temperatura Ambiente , Difração de Raios X
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