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1.
J Chem Phys ; 151(10): 105102, 2019 Sep 14.
Artigo em Inglês | MEDLINE | ID: mdl-31521088

RESUMO

The interactions between nanoparticles (NPs) and proteins, cells, and tissues, broadly known as nano-bio interactions, depend on the NP size and shape and on the characteristics of the NP coating layer, such as density, thickness, and chemical makeup. The dependence of nano-membrane interactions on the design parameters of ultrasmall nanostructures is studied by computer simulations. Considered here are spheres, plates, rings, rods, tubes, and helices made up of either bare magnetite or passivated gold, interacting with charged or zwitterionic membranes. The analysis reveals a strong dependence on shape, size, and layer composition of various quantities that characterize the nano-bio behavior, including binding modes and affinities. This sensitivity can be exploited to design nanostructures that bind preferentially to membranes or that stabilize or disrupt membrane structural integrity. The method used here is general and not limited to the ultrasmall regime, so it can be adopted to study other nano-bio interactions systematically. The implications for the distribution of NPs in cells and tissues (biodistribution) and for passive and active transmembrane transport are discussed, both important processes in biomedicine.


Assuntos
Benzoatos/química , Glutationa/química , Ouro/química , Nanopartículas de Magnetita/química , Nanopartículas Metálicas/química , Compostos de Sulfidrila/química
2.
Chem Commun (Camb) ; 55(80): 12008-12011, 2019 Oct 03.
Artigo em Inglês | MEDLINE | ID: mdl-31532419

RESUMO

Mussel-inspired enhancement of Fe3O4 catalysis was discovered towards a highly selective and sensitive colorimetric strategy for the magnetic separation-based evaluation of dopamine and/or levodopa in urine, in which the specific interaction of bis-catechol-containing analytes and mesoporous Fe3O4 NPs would form highly stable complexes of bis-catechol-Fe coordination.


Assuntos
Dopamina/urina , Levodopa/urina , Nanopartículas de Magnetita/química , Catálise , Catecóis/química , Colorimetria/métodos , Complexos de Coordenação/química , Dopamina/isolamento & purificação , Levodopa/isolamento & purificação , Oxirredução , Porosidade
3.
Int J Nanomedicine ; 14: 6481-6495, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31496698

RESUMO

Background: Despite the numerous pharmacological activities of quercetin, its biomedical application has been hampered, because of poor water solubility and low oral bioavailability. In the present study, we fabricated a novel form of quercetin-conjugated Fe3O4-ß-cyclodextrin (ßCD) nanoparticles (NPs), and the effect of these prepared NPs was evaluated in a chronic model of epilepsy. Methods: Quercetin-loaded NPs were prepared using an iron oxide core coated with ßCD and pluronic F68 polymer. The chronic model of epilepsy was developed by intraperitoneal injection of pentylenetetrazole (PTZ) at dose of 36.5 mg/kg every second day. Quercetin or its nanoformulation at doses of 25 or 50 mg/kg were administered intraperitoneally 10 days before PTZ injections and their applications continued 1 hour before each PTZ injection. Immunostaining was performed to evaluate the neuronal density and astrocyte activation of hippocampi. Results: Our data showed successful fabrication of quercetin onto Fe3O4-ßCD NPs. In comparison to free quercetin, quercetin NPs markedly reduced seizure behavior, neuronal loss, and astrocyte activation in a PTZ-induced kindling model. Conclusion: Overall, quercetin-Fe3O4-ßCD NPs might be regarded as an ideal therapeutic approach in epilepsy disorder.


Assuntos
Epilepsia/tratamento farmacológico , Nanopartículas de Magnetita/química , Quercetina/uso terapêutico , beta-Ciclodextrinas/química , Animais , Astrócitos/efeitos dos fármacos , Modelos Animais de Doenças , Hipocampo/patologia , Excitação Neurológica , Nanopartículas de Magnetita/administração & dosagem , Nanopartículas de Magnetita/ultraestrutura , Masculino , Camundongos , Neurônios/efeitos dos fármacos , Neurônios/patologia , Pentilenotetrazol/administração & dosagem , Quercetina/farmacologia , Espectroscopia de Infravermelho com Transformada de Fourier
4.
J Chromatogr A ; 1604: 460465, 2019 Oct 25.
Artigo em Inglês | MEDLINE | ID: mdl-31477277

RESUMO

A new analytical method based on the recently proposed stir bar sorptive-dispersive microextraction (SBSDME) technique has been developed to determine eight hazardous N-nitrosamines in cosmetic products. As previous step, a simple clean-up is carried out with hexane to remove those highly lipophilic compounds that disturb the SBSDME step. Subsequently, SBSDME is performed by using magnetic nanoparticles-metal organic framework composite, CoFe2O4/MIL-101(Fe), as sorbent to entrap the target analytes, which are later chemically desorbed and measured by liquid chromatography-tandem mass spectrometry (LC-MS/MS). The experimental variables related to the SBSDME procedure were studied to achieve the highest analytical signal. Under the most favorable conditions, the proposed method was validated providing good linearity; enrichment factors up to 62 depending on the analyte; limits of detection from 3 to 13 µg kg-1; and good repeatability values (RSD < 17.0%). Finally, the method was successfully applied to cosmetic samples composed either of lipophilic or hydrophilic matrices. Quantitative relative recoveries (96-109%) were obtained by using standard addition calibration. The present work expands the applicability of the SBSDME technique, whereas its analytical features make it useful to carry out the quality control of cosmetic samples.


Assuntos
Técnicas de Química Analítica/métodos , Cosméticos/química , Nanopartículas de Magnetita/química , Estruturas Metalorgânicas/química , Nitrosaminas/análise , Cromatografia Líquida , Cosméticos/normas , Interações Hidrofóbicas e Hidrofílicas , Limite de Detecção , Microextração em Fase Líquida , Espectrometria de Massas em Tandem
5.
Pharm Res ; 36(10): 147, 2019 Aug 14.
Artigo em Inglês | MEDLINE | ID: mdl-31414240

RESUMO

PURPOSE: The aim was to design and thoroughly characterize monodisperse Fe3O4@SiO2-Ag nanoparticles with strong antibacterial properties, which makes them a candidate for targeting bacterial infections. METHODS: The monodisperse Fe3O4 nanoparticles were prepared by oleic acid-stabilized thermal decomposition of Fe(III) oleate; the particles were coated with silica shell using a water-in-oil reverse microemulsion, involving hydrolysis and condensation of tetramethyl orthosilicate. Resulting Fe3O4@SiO2 particles were modified by (3-mercaptopropyl)trimethoxysilane to introduce 1.1 mmol SH/g. Finally, the Fe3O4@SiO2-SH nanoparticles were decorated with silver nanoclusters formed by reduction of silver nitrate with NaBH4. The particles were analyzed by FTIR, X-ray photoelectron and atomic absorption spectroscopy, dynamic light scattering and vibrating sample magnetometry. The antibacterial activity of the Fe3O4@SiO2 and Fe3O4@SiO2-Ag nanoparticles was tested against Gram-positive Staphylococcus aureus and Gram-negative Escherichia coli bacteria cultivated on Luria agar plates or in Luria broth. RESULTS: The superparamagnetic Fe3O4@SiO2-Ag nanoparticles (21 nm in diameter; saturation magnetization 26 A∙m2/kg) were successfully obtained and characterized. Inhibitory and toxic effects against bacteria were documented by incubation of the Fe3O4@SiO2-Ag nanoparticles with Staphylococcus aureus and Escherichia coli. CONCLUSIONS: The combination of magnetic properties together with bactericidal effects is suitable for the disinfection of medical instruments, water purification, food packaging, etc.


Assuntos
Antibacterianos/química , Nanopartículas de Magnetita/química , Prata/química , Antibacterianos/farmacologia , Escherichia coli/efeitos dos fármacos , Ácido Oleico/química , Tamanho da Partícula , Silanos/química , Dióxido de Silício/química , Prata/farmacologia , Staphylococcus aureus/efeitos dos fármacos , Propriedades de Superfície
6.
Einstein (Sao Paulo) ; 17(4): eAO4786, 2019 Aug 01.
Artigo em Inglês, Português | MEDLINE | ID: mdl-31390427

RESUMO

OBJECTIVE: To evaluate the potential of magnetic hyperthermia using aminosilane-coated superparamagnetic iron oxide nanoparticles in glioblastoma tumor model. METHODS: The aminosilane-coated superparamagnetic iron oxide nanoparticles were analyzed as to their stability in aqueous medium and their heating potential through specific absorption rate, when submitted to magnetic hyperthermia with different frequencies and intensities of alternating magnetic field. In magnetic hyperthermia in vitro assays, the C6 cells cultured and transduced with luciferase were analyzed by bioluminescence in the absence/presence of alternating magnetic field, and also with and without aminosilane-coated superparamagnetic iron oxide nanoparticles. In the in vivo study, the measurement of bioluminescence was performed 21 days after glioblastoma induction with C6 cells in rats. After 24 hours, the aminosilane-coated superparamagnetic iron oxide nanoparticles were implanted in animals, and magnetic hyperthermia was performed for 40 minutes, using the best conditions of frequency and intensity of alternating magnetic field tested in the in vitro study (the highest specific absorption rate value) and verified the difference of bioluminescence before and after magnetic hyperthermia. RESULTS: The aminosilane-coated superparamagnetic iron oxide nanoparticles were stable, and their heating capacity increased along with higher frequency and intensity of alternating magnetic field. The magnetic hyperthermia application with 874kHz and 200 Gauss of alternating magnetic field determined the best value of specific absorption rate (194.917W/g). When these magnetic hyperthermia parameters were used in in vitro and in vivo analysis, resulted in cell death of 52.0% and 32.8%, respectively, detected by bioluminescence. CONCLUSION: The magnetic hyperthermia was promissing for the therapeutical process of glioblastoma tumors in animal model, using aminosilane-coated superparamagnetic iron oxide nanoparticles, which presented high specific absorption rate.


Assuntos
Neoplasias Encefálicas/terapia , Compostos Férricos/uso terapêutico , Glioblastoma/terapia , Hipertermia Induzida/métodos , Terapia de Campo Magnético/métodos , Nanopartículas de Magnetita/uso terapêutico , Análise de Variância , Animais , Temperatura Corporal , Linhagem Celular Tumoral , Modelos Animais de Doenças , Compostos Férricos/química , Medições Luminescentes , Nanopartículas de Magnetita/química , Masculino , Ratos Wistar , Valores de Referência , Reprodutibilidade dos Testes , Fatores de Tempo , Resultado do Tratamento
7.
Life Sci ; 234: 116787, 2019 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-31445028

RESUMO

Iron deficiency anemia (IDA) is a major worldwide public health problem. This is due to its prevalence among infants, children, adolescents, pregnant and reproductive age women. Ferrous sulfate (FeSO4) is the first line therapy for iron IDA. Unfortunately, it is reported that FeSO4 suffers from low absorption rate in the body and itself exhibits severe side effects. Herein, iron oxide magnetic nanoparticles-loaded liposomes (LMNPs) are prepared, characterized and evaluated as a treatment regimen for IDA in Wistar rats (as an animal model). Iron oxide magnetic nanoparticles (MNPs) are prepared and loaded into liposomes using the thin film hydration method. The size of the prepared formulations is in the range 10-100 nm, thus it can avoid the reticular endothelial system (RES), and increased their blood circulation time. For in vivo assessment, thirty-five Wistar rats are divided into 5 groups (n = 7): negative control group, positive control group, and three groups treated with different iron formulations (FeSO4, MNPs and LMNPs). Anemia is induced in the anemic groups by the bleeding method and then treatment started with different iron compounds administrated orally for 13 days. Hematological parameters are followed up during the treatment period. Results indicate that, in the LMNPs group, the hematological parameters turn to normal values and the histopathological structures of the liver, spleen and kidney remain normal. This proves that liposome increases the bioavailability of MNPs. In conclusion, LMNPs demonstrate superiority as a therapeutic regimen for the treatment of IDA among the tested iron formulations.


Assuntos
Anemia Ferropriva/tratamento farmacológico , Compostos Ferrosos/administração & dosagem , Hematínicos/administração & dosagem , Lipossomos/química , Nanopartículas de Magnetita/química , Anemia Ferropriva/sangue , Animais , Disponibilidade Biológica , Feminino , Compostos Ferrosos/farmacocinética , Compostos Ferrosos/uso terapêutico , Hematínicos/farmacocinética , Hematínicos/uso terapêutico , Hemoglobinas/análise , Lipossomos/ultraestrutura , Nanopartículas de Magnetita/ultraestrutura , Ratos Wistar
8.
J Nanobiotechnology ; 17(1): 87, 2019 Aug 06.
Artigo em Inglês | MEDLINE | ID: mdl-31387604

RESUMO

BACKGROUND: Adoptive T cell-transfer (ATC) therapy is a highly promising cancer-treatment approach. However, in vivo-administered T cells tend to disperse, with only a small proportion reaching the tumour. To remedy this, magnetic targeting of T cells has been recently explored. Magnetic nanoparticles (MNPs) functionalised with antibodies were attached to effector T cells and magnetically recruited to tumour sites under MRI guidance. In this study, we investigated whether 3-aminopropyl-triethoxysilane (APS)-coated MNPs directly attached to CD8+ T cell membranes could also magnetically target and accumulate tumour-specific CD8+ T cells in solid tumours using an external magnetic field (EMF). As it has been shown that T cells associated with APS-coated MNPs are retained in lymph nodes (LNs), and tumour-draining LNs are the most common sites of solid-tumour metastases, we further evaluated whether magnetic targeting of APS-MNP-loaded CD8+ T cells could cause them to accumulate in tumour-draining LNs. RESULTS: First, we show that antigen-specific CD8+ T cells preserve their antitumor activity in vitro when associated with APS-MNPs. Next, we demonstrate that the application of a magnetic field enhanced the retention of APS-MNP-loaded OT-I CD8+ T cells under flow conditions in vitro. Using a syngeneic mouse model, we found similar numbers of APS-MNP-loaded OT-I CD8+ T cells and OT-I CD8+ T cells infiltrating the tumour 14 days after cell transfer. However, when a magnet was placed near the tumour during the transfer of tumour-specific APS-MNP-loaded CD8+ T cells to improve tumour infiltration, a reduced percentage of tumour-specific T cells was found infiltrating the tumour 14 days after cell transfer, which was reflected in a smaller reduction in tumour size compared to tumour-specific CD8+ T cells transferred with or without MNPs in the absence of a magnetic field. Nonetheless, magnet placement near the tumour site during cell transfer induced infiltration of activated tumour-specific CD8+ T cells in tumour-draining LNs, which remained 14 days after cell transfer. CONCLUSIONS: The use of an EMF to improve targeting of tumour-specific T cells modified with APS-MNPs reduced the percentage of these cells infiltrating the tumour, but promoted the retention and the persistence of these cells in the tumour-draining LNs.


Assuntos
Transferência Adotiva , Linfócitos T CD8-Positivos/transplante , Linfonodos/patologia , Linfócitos do Interstício Tumoral/imunologia , Nanopartículas de Magnetita/química , Neoplasias Experimentais/terapia , Animais , Linfócitos T CD8-Positivos/imunologia , Linhagem Celular Tumoral , Permeabilidade da Membrana Celular , Proliferação de Células , Sobrevivência Celular , Feminino , Linfonodos/imunologia , Ativação Linfocitária , Linfócitos do Interstício Tumoral/patologia , Camundongos Endogâmicos C57BL , Transplante de Neoplasias , Neoplasias Experimentais/imunologia , Neoplasias Experimentais/patologia , Propilaminas/química , Silanos/química
9.
10.
Phys Chem Chem Phys ; 21(34): 18741-18752, 2019 Aug 28.
Artigo em Inglês | MEDLINE | ID: mdl-31424464

RESUMO

Medical application of nanotechnology implies the development of nanomaterials capable of being functional in different biological environments. In this sense, elongated nanoparticles (e-MNPs) with high-aspect ratio have demonstrated more effective particle cellular internalization, which is favoured by the increased surface area. This paper makes use of an environmentally friendly hydrothermal method to produce magnetic iron oxide e-MNPs, starting from goethite precursors. At high temperatures (Td) goethite transforms into hematite, which subsequently reduces to magnetite when exposed to a hydrogen atmosphere for a certain time. It is shown that by adjusting Td it is possible to obtain Fe3O4 e-MNPs with partially controlled specific surface area and magnetic properties, attributed to different porosity of the samples. The particles' efficiencies for diagnostic and therapeutic purposes (in magnetic resonance imaging and magnetic fluid hyperthermia, respectively) are very good in terms of clinical standards, some samples showing transversal proton nuclear relaxivity r2 (B0 = 1.33 T) = 340 s-1 mM-1 and specific absorption rate SAR > 370 W g-1 at high field amplitudes (B0 = 55 mT). Direct correlations between the SAR, relaxivity, magnetic properties and porosity of the samples are found, and the physico-chemical processes underneath these correlations are investigated. Our results open the possibility of using very efficient high-aspect ratio elongated nanoparticles with optimized chemico-physical properties for biomedical applications.


Assuntos
Nanopartículas de Magnetita/química , Temperatura Alta , Hidrogênio/química , Magnetismo , Conformação Molecular , Fenômenos Físicos , Dióxido de Silício/química , Propriedades de Superfície
11.
Int J Nanomedicine ; 14: 4397-4412, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31417251

RESUMO

Background: Graphene magnetite nanocomposites (G/Fe3O4) exhibit light photothermal conversion upon enhancement by 808 nm IR laser excitation. We evaluated the cytotoxic and photothermal effects of G/Fe3O4 on a HepG2 human liver cancer cell model. Methods: Graphene nanosheets (rGO), magnetite nanoparticles (Fe3O4), and G/Fe3O4 were prepared by chemical methods and characterized using transmission electron microscopy, Raman spectroscopy, zeta analysis, and vibrating sample magnemeter. Dark and light cytotoxicity were screened with colorimetric Sulforhodamine B cell viability assay after 24 and 48 hours. DNA fragmentation and some apoptotic genes on a transcriptional RNA level expression were performed. All prepared nanomaterials were evaluated for their photothermal effect at concentrations of 10 and 50 µg/mL. The power density incident on the cells by 300 mW 808 IR diode laser was 0.597 W/cm2. Results: Treatment of HepG2 with 400 µg/mL of rGO, Fe3O4, and G/Fe3O4 showed alteration in cell morphology after 24 hours of cell treatment and revealed toxic effects on cellular DNA. Evaluation of the cytotoxic effects showed messenger RNA (mRNA) in ß-actin and Bax apoptotic genes, but no expression of mRNA of caspase-3 after 24 hours of cell exposure, suggesting the involvement of an intrinsic apoptotic caspase-independent pathway. A photothermal effect was observed for G/Fe3O4 after irradiation of the HepG2 cells. A marked decrease was found in cell viability when treated with 10 and 50 µg/mL G/Fe3O4 from 40% to 5% after 48 hours of cell treatment. Conclusion: Results indicate that G/Fe3O4 nanocomposite was effective at transformation of light into heat and is a promising candidate for cancer therapy.


Assuntos
Grafite/química , Hipertermia Induzida , Raios Infravermelhos , Neoplasias Hepáticas/terapia , Nanopartículas de Magnetita/química , Modelos Biológicos , Nanocompostos/química , Fototerapia , Apoptose/genética , Sobrevivência Celular/genética , Fragmentação do DNA , Regulação Neoplásica da Expressão Gênica , Células Hep G2 , Humanos , Neoplasias Hepáticas/genética , Neoplasias Hepáticas/patologia , Nanopartículas de Magnetita/ultraestrutura , Nanocompostos/ultraestrutura , Oxirredução , Análise Espectral Raman , Eletricidade Estática , Difração de Raios X
12.
Int J Nanomedicine ; 14: 5785-5797, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31440047

RESUMO

Introduction: The targeted delivery of anti-cancer drugs to tumor tissue has been recognized as a promising strategy to increase their therapeutic efficacy and reduce side effects. Mesoporous silica-coated superparamagnetic Fe3O4 nanoparticles (NH2-MSNs), a kind of nanocarrier, can passively enter tumor tissues to enhance the permeability and retention of drugs. However, NH2-MSNs do not specifically bind to cancer cells. This drawback encouraged us to develop a more efficient nanocarrier for cancer therapy. Methods: Herein, we describe the development of an effective nanocarrier based on NH2-MSNs, which were modified with hyaluronic acid on their surface (HA-MSNs) and loaded with doxorubicin (DOX). We have successfully fabricated uniform spherical HA-MSNs nanocarriers. The targeting ability of this delivery system was evaluated through specific uptake by cells and IVIS imaging. Results: DOX-HA-MSNs nanocarriers displayed more dramatic cytotoxic activity against 4T1 breast cancer cells compared to GES-1 gastric mucosa cells. In vivo results revealed that once DOX-HA-MSNs nanocarriers are exposed to an external magnetic field, they could be rapidly attracted to the magnet and effectively cross the cytoplasmic membrane via CD44 receptor-mediated transcytosis. This allows them to access the cancer cell cytoplasm and release DOX based on changes in the physiological environment. Both in vitro and in vivo results demonstrated that the HA-MSNs nanocarriers provided better therapeutic efficacy. Conclusion: The HA-MSNs nanocarriers represent an effective new paradigm to treat cancers due to active targeting to the tumor cells. Moreover, the specific uptake by the tumor effectively protects normal tissues to reduce off-target side effects. The reported findings support further investigation of HA-MSNs for cancer therapy.


Assuntos
Dextranos/química , Sistemas de Liberação de Medicamentos , Ácido Hialurônico/química , Nanopartículas de Magnetita/química , Dióxido de Silício/química , Animais , Linhagem Celular Tumoral , Doxorrubicina/administração & dosagem , Doxorrubicina/farmacologia , Humanos , Nanopartículas de Magnetita/ultraestrutura , Camundongos , Nanopartículas/administração & dosagem , Neoplasias/tratamento farmacológico , Neoplasias/patologia , Espectroscopia Fotoeletrônica , Porosidade , Espectroscopia de Infravermelho com Transformada de Fourier , Ensaios Antitumorais Modelo de Xenoenxerto
13.
J Nanobiotechnology ; 17(1): 81, 2019 Jul 08.
Artigo em Inglês | MEDLINE | ID: mdl-31286976

RESUMO

BACKGROUND: Magnetic nanoparticles (MNPs) are characterized by unique physicochemical and biological properties that allow their employment as highly biocompatible drug carriers. Gelsolin (GSN) is a multifunctional actin-binding protein involved in cytoskeleton remodeling and free circulating actin sequestering. It was reported that a gelsolin derived phosphoinositide binding domain GSN 160-169, (PBP10 peptide) coupled with rhodamine B, exerts strong bactericidal activity. RESULTS: In this study, we synthesized a new antibacterial and antifungal nanosystem composed of MNPs and a PBP10 peptide attached to the surface. The physicochemical properties of these nanosystems were analyzed by spectroscopy, calorimetry, electron microscopy, and X-ray studies. Using luminescence based techniques and a standard killing assay against representative strains of Gram-positive (Staphylococcus aureus MRSA Xen 30) and Gram-negative (Pseudomonas aeruginosa Xen 5) bacteria and against fungal cells (Candida spp.) we demonstrated that magnetic nanoparticles significantly enhance the effect of PBP10 peptides through a membrane-based mode of action, involving attachment and interaction with cell wall components, disruption of microbial membrane and increased uptake of peptide. Our results also indicate that treatment of both planktonic and biofilm forms of pathogens by PBP10-based nanosystems is more effective than therapy with either of these agents alone. CONCLUSIONS: The results show that magnetic nanoparticles enhance the antimicrobial activity of the phosphoinositide-binding domain of gelsolin, modulate its mode of action and strengthen the idea of its employment for developing the new treatment methods of infections.


Assuntos
Antibacterianos/química , Antifúngicos/química , Gelsolina/química , Nanopartículas de Magnetita/química , Fragmentos de Peptídeos/química , Biofilmes , Candida/efeitos dos fármacos , Membrana Celular/metabolismo , Ouro/química , Staphylococcus aureus Resistente à Meticilina/efeitos dos fármacos , Testes de Sensibilidade Microbiana , Nanoconchas/química , Plâncton , Pseudomonas aeruginosa/efeitos dos fármacos , Rodaminas/química
14.
J Photochem Photobiol B ; 197: 111547, 2019 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-31325773

RESUMO

In the present work, Fe3O4 nanoparticles with superparamagnetic properties were prepared and capped by using Chitosan. The synthesized NPs were studied by using transmission electron microscopy (TEM) and Fourier transform infrared (FTIR) spectroscopy. Average particle size and surface charge of the synthesized NPs were characterized by using Malvern Zetasizer instrument. TEM images showed the morphology and size distribution of uncoated Fe3O4 NPs, exhibiting the uniform sized NPS with an average particle size of about 10 nm. Vibrating Scanning Magnetometry (VSM) experiments, showed the superparamagnetic nature of the prepared nanoparticles. Fe3O4 NPs showed ferromagnetic magnetization which is very sensitive towards the sample's nanostructure. The results of paramagnetic studies exhibited the substantial reduction in paramagnetic behavior after Chitosan coating but sufficient for responding in magnetic field. Further, the in-vitro ability of the Chitosan coated Fe3O4 NPs as contrast agents in efficient Ultra sound/Magnetic resonance (US/MR) imaging was investigated. These findings demonstrated that the Chitosan coated super para magnetic iron oxide nanoparticles (SPION) have reported significant contrast-enhanced imaging potential for dual-mode US/MR imaging. Hence, the prepared Chitosan coated SPION composites administration serve as potential guide in the diagnosis and treatment of cancers.


Assuntos
Óxido Ferroso-Férrico/química , Imagem por Ressonância Magnética , Nanopartículas de Magnetita/química , Neoplasias/diagnóstico , Ultrassonografia , Quitosana/química , Humanos , Microscopia Eletrônica de Transmissão , Neoplasias/diagnóstico por imagem , Tamanho da Partícula , Espectroscopia de Infravermelho com Transformada de Fourier , Propriedades de Superfície
15.
Int J Nanomedicine ; 14: 4293-4307, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31354261

RESUMO

Purpose: Antibodies are key reagents in the development of immunoassay. We attempted to develop high-performance CPP immunoassays using high-affinity monoclonal antibodies prepared via cytokine-assisted immunization. Methods: We used fetal liver tyrosine kinase 3 ligand (Flt3L), CC subtype chemokine ligand 20 (CCL20), and granulocyte-macrophage colony-stimulating factor (GM-CSF) to assist traditional subcutaneous immunization of preparing high-affinity monoclonal antibodies, and further to develop high-performance immunoassay methods for CPP. Results: This novel immune strategy significantly enhanced immune response against CPP. Six anti-CPP monoclonal antibodies (mAbs) with high affinity were successfully screened and selected for application in a fully automated magnetic chemiluminescence immunoassay (CLIA). This robust and rapid assay can efficiently detect CPP in the range of 1.2-1250 pmol L-1 with a detection limit of 6.25 pmol L-1. Significantly, the whole incubation process can be completed in 30 min as compared to about 4.5 hr for the control ELISA kit. Furthermore, this assay exhibited high sensitivity and specificity, low intra-assay and inter-assay coefficients of variation (CVs < 15%). The developed assay was applied in the detection of CPP in 115 random serum samples and results showed a high correlation with data obtained using a commercially available ELISA kit (correlation coefficient, 0.9737). Conclusion: Our assay could be applied in the point-of-care testing of CPP in the serum samples, and also the method developed in this study could be adopted to explore the detection and diagnosis of other biomarkers for various diseases.


Assuntos
Anticorpos Monoclonais/imunologia , Citocinas/metabolismo , Glicopeptídeos/sangue , Imunização , Imunoensaio/métodos , Medições Luminescentes/métodos , Testes Imediatos , Animais , Anticorpos Monoclonais/biossíntese , Feminino , Humanos , Concentração de Íons de Hidrogênio , Limite de Detecção , Nanopartículas de Magnetita/química , Camundongos Endogâmicos BALB C , Sensibilidade e Especificidade
16.
Int J Nanomedicine ; 14: 4517-4528, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31354271

RESUMO

Purpose: We developed a contrast agent for targeting E-selectin expression. We detected the agent using magnetic resonance imaging (MRI) in vivo in nude mice that had undergone nasopharyngeal carcinoma (NPC) metastasis. Methods: Sialyl Lewis X (sLeX) was conjugated with ultrasmall superparamagnetic iron oxide (USPIO) nanoparticles. Hydrodynamic size, polydispersity index, and ζ-potential of USPIO-polyethylene glycol (PEG) nanoparticles and USPIO-PEG-sLeX nanoparticles were measured. Component changes in nanoparticles of USPIO, USPIO-PEG, and USPIO-PEG-sLeX were analyzed by thermogravimetric analysis and Fourier-transform infrared spectroscopy. A model of NPC metastasis to inguinal lymph nodes in nude mice was used to investigate characteristics of the USPIO-PEG-sLeX nanoparticles in vivo. We investigated the ability of the T2* value, change in T2* value (ΔT2* value), and enhancement rate (ER) to assess accumulation of USPIO-PEG-sLeX nanoparticles quantitatively in mice of a metastasis group and control group. Four MRI scans were undertaken for each mouse. The first scan (t0) was done before administration of USPIO-PEG-sLeX nanoparticles (0.1 mL) via the tail vein. The other scans were carried out at 0 (t1), 1 (t2), and 2 hours (t3) postinjection. The mean optical density was used to reflect E-selectin expression. Results: sLeX was labeled onto USPIO successfully. In vivo, there were significant interactions between the groups and time for T2* values after administration of USPIO-PEG-sLeX nanoparticles. Six parameters (T2* at t2, ΔT2* at t1, ΔT2* at t2, ER at t1, ER at t2, and ER at t3) were correlated with the mean optical density. Conclusion: USPIO-PEG-sLeX nanoparticles can be used to assess E-selectin expression quantitatively. Use of such molecular probes could enable detection of early metastasis of NPC, more accurate staging, and treatment monitoring.


Assuntos
Dextranos/química , Selectina E/metabolismo , Nanopartículas de Magnetita/química , Animais , Linhagem Celular Tumoral , Dextranos/ultraestrutura , Difusão Dinâmica da Luz , Feminino , Metástase Linfática , Imagem por Ressonância Magnética , Nanopartículas de Magnetita/ultraestrutura , Masculino , Camundongos Endogâmicos BALB C , Camundongos Nus , Neoplasias Nasofaríngeas/patologia , Metástase Neoplásica , Oligossacarídeos/metabolismo , Polietilenoglicóis/química , Eletricidade Estática , Termodinâmica
17.
Anal Chim Acta ; 1078: 161-167, 2019 Oct 31.
Artigo em Inglês | MEDLINE | ID: mdl-31358215

RESUMO

Sarcosine is a recently identified biomarker for prostate cancer. However, the rapid detection methods for sarcosine are relatively lack because of the low concentration and the presence of complicated interfering substances in serum or urine. In this manuscript, hollow nanospheres of Fe3O4 was synthesized and used as carrier to disperse Pt (Pt) nanoparticles. In order to achieve excellent electron transfer ability, we use polyaniline to coat Pt-Fe3O4 nanoparticles, and pyrolyze the polyaniline to carbon (C). Thus, hollow magnetic Pt-Fe3O4@C nanocomposites with good electron transfer ability are formed. The Pt-Fe3O4@C nanocomposites have high catalytic activity and stability. The nanocomposites were immobilized on glassy carbon electrode (GCE) to construct a nonenzyme hydrogen peroxide (H2O2) sensor (Pt-Fe3O4@C/GCE). We further construct a sensitive sarcosine biosensor by immobilizing sarcosine oxidase (SOx) on the Pt-Fe3O4@C/GCE. The high catalytic activity and good biocompatibility of Pt-Fe3O4@C nanocomposites greatly retained the bioactivity of immobilized SOx, and the prepared sarcosine biosensor has good electrocatalytic performance towards sarcosine. It has a linear detection range between 0.5 and 60 µM with a limit of detection (LOD) of 0.43 µM (the signal to noise ratio is 3), and the sensitivity is 3.45 nA µM-1 (48.8 nA µM-1 cm-2), which has the potential to be used for rapid screening of prostate cancer.


Assuntos
Nanopartículas de Magnetita/química , Nanocompostos/química , Sarcosina/sangue , Técnicas Biossensoriais/instrumentação , Técnicas Biossensoriais/métodos , Carbono/química , Técnicas Eletroquímicas/instrumentação , Técnicas Eletroquímicas/métodos , Eletrodos , Enzimas Imobilizadas/química , Humanos , Limite de Detecção , Platina/química , Sarcosina Oxidase/química
18.
Anal Chim Acta ; 1078: 24-31, 2019 Oct 31.
Artigo em Inglês | MEDLINE | ID: mdl-31358225

RESUMO

A novel electrochemical DNA biosensor was developed and MON89788 of soybean transgenic gene sequence was detected based on a strategy of rolling circle amplification (RCA) and gold nanoparticle cube (AuNPC)-labeled multiple probes. First, the mercapto-modified capture DNA was immobilized on the surface of the Fe3O4@Au magnetic nanoparticles via an Au-S bond, and the capture DNA was opened and complementarily hybridized with the target DNA to form a double-stranded DNA. In the 10 × reaction buffer, Exonuclease III (ExoIII) specifically recognized and sheared the double-stranded DNA to release the target DNA, which led to the next round of reaction. Afterward, AuNP cube-loaded ssDNA (AuNPC/DNA) was added with the rolling circle reaction with the help of Phi29 DNA polymerase and T4 ligase. Finally, [Ru(NH3)6]3+ was attracted directly by the anionic phosphate of ssDNA via electrostatic interaction. The determination was carried out by using chronocoulometry (CC), and the CC signal was recorded. The mass amount of DNA strands extended infinitely on the AuNPs cube and numerous [Ru(NH3)6]3+ were absorbed, thus the detected signal was highly amplified. The corresponding CC signal showed a good linear relationship with the logarithm of the target DNA concentration in the range of 1 × 10-16 to 1 × 10-7 mol L-1, with a detection limit of 4.5 × 10-17 mol L-1. Specific gene sequence of MON89788 in soybean samples was determined, and the recoveries ranged from 97.3% to 102.0%. This sensor is one of the most sensitive sensors for genetic sequence assessment at present. Moreover, it demonstrates good selectivity, stability, and reproducibility.


Assuntos
Técnicas Biossensoriais/métodos , DNA de Plantas/análise , Técnicas Eletroquímicas/métodos , Plantas Geneticamente Modificadas/genética , Soja/genética , Sequência de Bases , Calibragem , Sondas de DNA/química , Sondas de DNA/genética , DNA de Plantas/química , DNA de Plantas/genética , Exodesoxirribonucleases/química , Ouro/química , Limite de Detecção , Nanopartículas de Magnetita/química , Técnicas de Amplificação de Ácido Nucleico/métodos , Hibridização de Ácido Nucleico , Oligodesoxirribonucleotídeos/química , Oligodesoxirribonucleotídeos/genética , Reprodutibilidade dos Testes , Compostos de Rutênio/química
19.
Anal Chim Acta ; 1078: 78-89, 2019 Oct 31.
Artigo em Inglês | MEDLINE | ID: mdl-31358231

RESUMO

Based on a one-step combustion fabrication approach, a novel magnetic porous carbon (MPC) was fabricated using filter paper as porous carbon source and iron salts as magnetic precursors. The textural properties of the MPC were characterized by transmission electron microscopy (TEM), Fourier transform infrared spectrometry (FT-IR), X-ray photoelectron spectroscopy (XPS), X-ray diffraction (XRD), vibration sample magnetometer (VSM) and nitrogen absorption-desorption isotherms. The as-prepared MPC possessed a high specific surface area, a microstructure comprised of mesopores and strong magnetic response. It was employed as a magnetic solid-phase extraction (MSPE) adsorbent for the determination of three non-steroidal anti-inflammatory drugs (NSAIDs) in environmental water and biological samples coupled with high performance liquid chromatography (HPLC). The main parameters affecting extraction efficiency were investigated in detail and a satisfactory performance was obtained under the optimal conditions. The calibration curves were linear over the concentration ranging from 1 to 1200 µg L-1 for ketoprofen (KET) and 2-1200 µg L-1 for naproxen (NAP) and diclofenac (DCF) with determination coefficients (R2) between 0.9995 and 0.9997. The limits of detection (LODs) were in the range of 0.2-0.4 µg L-1. The intra- and inter-day relative standard deviations (RSDs) were less than 4.03% and 8.72%, respectively. The recoveries ranged from 84.67% to 113.73% with RSDs less than 7.76%. The satisfactory results confirmed the great potential of the novel MPC adsorbent for the extraction of NSAIDs from complex sample matrices.


Assuntos
Anti-Inflamatórios não Esteroides/análise , Carbono/química , Diclofenaco/análise , Cetoprofeno/análise , Naproxeno/análise , Adsorção , Anti-Inflamatórios não Esteroides/sangue , Anti-Inflamatórios não Esteroides/urina , Diclofenaco/sangue , Diclofenaco/urina , Química Verde/métodos , Cetoprofeno/sangue , Cetoprofeno/urina , Limite de Detecção , Nanopartículas de Magnetita/química , Naproxeno/sangue , Naproxeno/urina , Porosidade , Rios/química , Extração em Fase Sólida/instrumentação , Extração em Fase Sólida/métodos , Poluentes Químicos da Água/análise
20.
Food Chem ; 299: 125144, 2019 Nov 30.
Artigo em Inglês | MEDLINE | ID: mdl-31323440

RESUMO

Magnetic nanoparticles were synthesised to extract Sudan dyes from chilli powders. The adsorbents used were magnetic ferroferric oxide nanoparticles coated with polystyrene. The extraction procedures for Sudan dyes comprised liquid-solid extraction and magnetic solid phase extraction. The conditions were optimised to achieve efficient magnetic solid phase extraction, including extraction and desorption time, type and volume of the desorption solvent, and the mass of the adsorbents. Repeatability tests showed satisfactory recovery rates of 80.2-115.8%, with a relative standard deviation <3.8%. The results suggested that the proposed extraction method was effective and efficient to extract Sudan dyes from chilli powders. The extraction process was simpler compared with traditional approaches because the adsorbents can be rapidly removed from the sample matrix using a permanent magnet. The use of recyclable adsorbents decreased the cost greatly. Chilli powder samples collected from local markets in Singapore were tested using the proposed method under optimum conditions.


Assuntos
Capsicum/química , Corantes/análise , Contaminação de Alimentos/análise , Nanopartículas de Magnetita/química , Compostos Azo/análise , Fracionamento Químico/métodos , Cromatografia Líquida de Alta Pressão , Análise de Alimentos/instrumentação , Análise de Alimentos/métodos , Pós/química , Reprodutibilidade dos Testes , Singapura , Extração em Fase Sólida/instrumentação , Extração em Fase Sólida/métodos
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