Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 1.376
Filtrar
1.
PLoS One ; 15(6): e0234524, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32579584

RESUMO

The purpose of this study was to evaluate the adherence of streptococci to disks of titanium (commercially pure titanium: CpTi) and zirconia (tetragonal zirconia polycrystals: TZP). CpTi and yttria-stabilized TZP disks with a mirror-polished surface were used as specimens. The arithmetic mean surface roughness (Ra and Sa) and the surface wettability of the experimental specimens were measured. For analyzing the outermost layer of the experimental specimens, X-ray photoelectron spectroscopy (XPS) analysis was performed. Streptococcus sanguinis, S. gordonii, S. oralis, and S. mutans were used as streptococcal bacterial strains. These bacterial cultures were grown for 24 h on CpTi and TZP. The number of bacterial adhesions was estimated using an ATP-bioluminescent assay, and scanning electron microscope (SEM) observation of the adhered bacterial specimens was performed. No significant differences in surface roughness or wettability were found between CpTi and TZP. In XPS analyses, outermost layer of CpTi included Ti0 and Ti4+, and outermost layer of TZP included Zr4+. In the cell adhesion assay, the adherences of S. sanguinis, S. gordonii, and S. oralis to TZP were significantly lower than those to CpTi (p < 0.05); however, significant difference was not observed for S. mutans among the specimens. The adherence to CpTi and TZP of S. mutans was significantly lower than that of S. sanguinis, S. gordonii, and S. oralis. These results were confirmed by SEM. S. sanguinis, S. gordonii, and S. oralis adhered less to TZP than to CpTi, but the adherence of S. mutans was similar to both surfaces. S. mutans was less adherent compare with the other streptococci tested in those specimens.


Assuntos
Aderência Bacteriana/efeitos dos fármacos , Streptococcus sanguis/efeitos dos fármacos , Titânio/química , Zircônio/química , Teste de Materiais , Microscopia Eletrônica de Varredura , Espectroscopia Fotoeletrônica , Streptococcus sanguis/química , Streptococcus sanguis/ultraestrutura , Propriedades de Superfície/efeitos dos fármacos , Ítrio/química
2.
Int J Nanomedicine ; 15: 1409-1420, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32184595

RESUMO

Background: Photothermal therapy with accurate and real-time temperature detection is desired in clinic. Upconversion nanocrystals (UCNs) are candidate materials for simultaneous temperature detection and photothermal agents carrying. However, the weak luminescence and multiple laser excitations of UCNs limit their application in thermal therapy. Materials and Methods: NaYF4:Yb3+,Er3+,Nd3+, PL-PEG-NH2, IR-806 and folic acid are selected as structural components. A nanoprobe (NP) integrated with efficient photothermal conversion and sensitive temperature detection capabilities is synthesized for precise photothermal therapy. The probes are based on near-infrared upconversion nanocrystals doped with Yb, Er and Nd ions, which can be excited by 808 nm light. IR-806 dye molecules are modified on the surface as molecular antennas to strongly absorb near-infrared photons for energy transfer and conversion. Results: The results show that under an 808 nm laser irradiation upconversion luminescence of the nanocrystals is enhanced based on both the Nd ion absorption and the FRET energy transfer of IR-806. The luminescence ratio at 520 and 545 nm is calculated to accurately monitor the temperature of the nanoparticles. The temperature of the nanoprobes increases significantly through energy conversion of the molecular antennas. The nanoparticles are found successfully distributed to tumor cells and tumor tissue due to the modification of the biocompatible molecules on the surface. Tumor cells can be killed efficiently based on the photothermal effect of the NPs. Under the laser irradiation, temperature at mouse tumor site increases significantly, tissue necrosis and tumor cell death can be observed. Conclusion: Precision photothermal therapy can thus be achieved by highly efficient near-infrared light absorption and accurate temperature monitoring, making it promising for tumor treatment, as well as the biological microzone temperature detection.


Assuntos
Nanopartículas/química , Fototerapia/métodos , Termografia/métodos , Animais , Linhagem Celular Tumoral , Érbio/química , Feminino , Raios Infravermelhos , Lasers , Luminescência , Neoplasias Mamárias Experimentais/terapia , Camundongos Endogâmicos BALB C , Neodímio/química , Temperatura , Itérbio/química , Ítrio/química
3.
PLoS One ; 15(2): e0229360, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32092128

RESUMO

This study evaluated the von Mises stress (MPa) and equivalent strain occurring around monolithic yttria-zirconia (Zir) implant using three clinically simulated finite element analysis (FEA) models for a missing maxillary central incisor. Two unidentified patients' cone-beam computed tomography (CBCT) datasets with and without right maxillary central incisor were used to create the FEA models. Three different FEA models were made with bone structures that represent a healed socket (HS), reduced bone width edentulous site (RB), and immediate extraction socket with graft (EG). A one-piece abutment-implant fixture mimicking Straumann Standard Plus tissue level RN 4.1 X 11.8mm, for titanium alloy (Ti) and Zir were modeled. 178 N oblique load and 200 N vertical load were used to simulate occlusal loading. Von Mises stress and equivalent strain values for around each implant model were measured. Within the HS and RB models the labial-cervical region in the cortical bone exhibited highest stress, with Zir having statistically significant lower stress-strain means than Ti in both labial and palatal aspects. For the EG model the labial-cervical area had no statistically significant difference between Ti and Zir; however, Zir performed better than Ti against the graft. FEA models suggest that Ti, a more elastic material than Zir, contributes to the transduction of more overall forces to the socket compared to Zir. Thus, compared to Ti implants, Zir implants may be less prone to peri-implant bone overloading and subsequent bone loss in high stress areas especially in the labial-cervical region of the cortical bone. Zir implants respond to occlusal loading differently than Ti implants. Zir implants may be more favorable in non-grafted edentulous or immediate extraction with grafting.


Assuntos
Implantes Dentários para Um Único Dente , Análise do Estresse Dentário/métodos , Análise de Elementos Finitos , Zircônio/química , Fenômenos Biomecânicos , Simulação por Computador , Humanos , Incisivo/química , Teste de Materiais , Maxila/patologia , Estresse Mecânico , Ítrio/química
4.
Talanta ; 207: 120294, 2020 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-31594563

RESUMO

Dual-functional nanosensors based on small molecule regulation can be widely used due to their simplicity, high sensitivity and selectivity. Herein, glutathione (GSH) calibrated dual-functional system for GSH and cadmium ions (Cd2+) detection based on fluorescence resonance energy transfer (FRET) between NH2-NaYF4:Yb,Er/NaYF4@SiO2 upconversion nanoparticles (UCNPs) and gold nanoparticles (AuNPs) is designed. Unmodified AuNPs are easy to aggregate in high-salt solution and thereby quenching the red emission of UCNPs. The presence of GSH prevents the aggregation of AuNPs, so GSH can be detected by the changes in the color of solution and the recovery of red emission of UCNPs. However, Cd2+ can interact with GSH, which makes AuNPs easy to aggregate, resulting in a gradual decrease in red emission of UCNPs. The fluorescence response of the system is linear with the concentrations of GSH and Cd2+ in a wide range of concentrations, with low detection limits of 0.016 µM and 0.059 µM, respectively. Furthermore, the nanosensor demonstrates high selectivity for GSH and Cd2+ detection and can be applied for the detection of GSH in human plasma and Cd2+ in drinking water.


Assuntos
Cádmio/análise , Transferência Ressonante de Energia de Fluorescência , Fluoretos/química , Glutationa/análise , Ouro/química , Nanopartículas Metálicas/química , Dióxido de Silício/química , Ítrio/química , Água Potável/química , Glutationa/sangue , Humanos
5.
Colloids Surf B Biointerfaces ; 185: 110618, 2020 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-31706145

RESUMO

Alkaline phosphatase (ALP) is an important biomarker for diagnosis, and the abnormal level of serum ALP is closely related to a variety of diseases. In present work, a ratiometric fluorescence probe based on hybrid nanoparticles CDs@YVO4: Dy3+ nanoparticle is introduced for alkaline phosphatase (ALP) activity determination. The CDs@YVO4: Dy3+ probe is constructed by the carbon dots (CDs) and YVO4: Dy3+ through a simple mixing method, in which the blue emission of CDs at 405 nm acts as the calibrated signal, the green emission of YVO4: Dy3+ at 574 nm decreased with the increasing targets ALP, and used as the output signal. In addition, the Cu2+ and pyrophosphate (PPi) were also employed in this strategy to utilize the excellent fluorescnece quenching efficiency of Cu2+ to the Dy3+ ions emission of CDs@YVO4: Dy3+, as well as the strong affinity of PPi for Cu2+. In the presence of analyts ALP, ALP catalyzes the hydrolysis of PPi, causing the release of Cu2+, resulting in the Dy3+ ions emission quenched, while the CDs emission at 405 nm retained unchanged, based on this, we designed the off-on-off ratiometric fluorescence platform for ALP sensing. The experiment result shows that the ratio of F574/F405 is linear to the concentration of ALP in arange of 0.05∼3000 U/L with a detection limit of 0.04 U/L, which is comparable or better than those reported fluorescence probe, especially the calibrated signal introduction of CDs can eliminate the background interference, improve the accuracy of proposed probe greatly. Furthermore, the discrimination of ALP enzyme inhibitor with the IC50 of 26 µM, and ALP concentration in real human serum sample has also demonstrated the applicability of CDs@YVO4: Dy3+ fluorescence sensor well.


Assuntos
Fosfatase Alcalina/metabolismo , Corantes Fluorescentes/química , Vanadatos/química , Ítrio/química , Fosfatase Alcalina/sangue , Carbono/química , Fluorescência , Nanopartículas/química , Nanopartículas/ultraestrutura , Espectroscopia Fotoeletrônica , Pontos Quânticos/química , Espectroscopia de Infravermelho com Transformada de Fourier
6.
Nanotechnology ; 31(14): 145101, 2020 Apr 03.
Artigo em Inglês | MEDLINE | ID: mdl-31846954

RESUMO

Recently, the wide application of upconversion nanoparticles (UCNPs) in the field of bioimaging has raised the requirement of biocompatibility. Current cytocompatibility studies on UCNPs mainly focus on cancer cells; however, their potential effects on normal cells are rarely addressed. Herein, the cellular effects of a trace amount of ligand-free NaYF4:Yb/Er nanocrystals on the differentiation of rat bone mesenchymal stem cells (rBMSCs) were investigated. First, due to their excellent upconversion fluorescent properties, the cellular uptake of ligand-free NaYF4:Yb/Er nanocrystals was confirmed by confocal laser scanning microscopy, and a homogeneous cytoplasmic distribution was imaged. Second, the viability of the rBMSCs cultured with a series of concentrations of nanoparticles (0, 30, 300, and 3000 ng ml-1) was evaluated, and a dose threshold was determined. Third, the effects of ligand-free NaYF4:Yb/Er nanocrystals on the osteogenesis of the rBMSCs were intensively characterized. The alkaline phosphatase activity assay, quantitative real time polymerase chain reaction for related osteogenic genes, and immunofluorescence staining of specific biomarkers and mineral deposits demonstrated that the ligand-free NaYF4:Yb/Er nanocrystals at a proper concentration can enhance osteogenic differentiation. Finally, intracytoplasmic lipid detection showed that the adipogenic differentiation of rBMSCs might be inhibited in the presence of ligand-free NaYF4:Yb/Er nanocrystals. Meanwhile, these results showed that the effects of ligand-free NaYF4:Yb/Er nanocrystals on rBMSCs were concentration-dependent and reciprocal between osteogenic and adipogenic differentiation. This work provides new insights into the exploring the biocompatibility of UCNPs and will benefit the research community engaged in nanotechnology and biomedicine.


Assuntos
Adipogenia/efeitos dos fármacos , Érbio/química , Fluoretos/farmacologia , Células-Tronco Mesenquimais/citologia , Osteogênese/efeitos dos fármacos , Itérbio/química , Ítrio/farmacologia , Animais , Diferenciação Celular/efeitos dos fármacos , Sobrevivência Celular/efeitos dos fármacos , Células Cultivadas , Relação Dose-Resposta a Droga , Fluoretos/química , Células HeLa , Humanos , Ligantes , Células-Tronco Mesenquimais/efeitos dos fármacos , Microscopia Confocal , Nanopartículas , Ratos , Coloração e Rotulagem , Ítrio/química
8.
Molecules ; 24(22)2019 Nov 09.
Artigo em Inglês | MEDLINE | ID: mdl-31717490

RESUMO

(1) Background: Nanomedicine has recently emerged as a promising field, particularly for cancer theranostics. In this context, nanoparticles designed for imaging and therapeutic applications are of interest. We, therefore, studied the encapsulation of upconverting nanoparticles in mesoporous organosilica nanoparticles. Indeed, mesoporous organosilica nanoparticles have been shown to be very efficient for drug delivery, and upconverting nanoparticles are interesting for near-infrared and X-ray computed tomography imaging, depending on the matrix used. (2) Methods: Two different upconverting-based nanoparticles were synthesized with Yb3+-Er3+ as the upconverting system and NaYF4 or BaLuF5 as the matrix. The encapsulation of these nanoparticles was studied through the sol-gel procedure with bis(triethoxysilyl)ethylene and bis(triethoxysilyl)ethane in the presence of CTAB. (3) Results: with bis(triethoxysilyl)ethylene, BaLuF5: Yb3+-Er3+, nanoparticles were not encapsulated, but anchored on the surface of the obtained mesoporous nanorods BaLuF5: Yb3+-Er3+@Ethylene. With bis(triethoxysilyl)ethane, BaLuF5: Yb3+-Er3+ and NaYF4: Yb3+-Er3+nanoparticles were encapsulated in the mesoporous cubic structure leading to BaLuF5: Yb3+-Er3+@Ethane and NaYF4: Yb3+-Er3+@Ethane, respectively. (4) Conclusions: upconversion nanoparticles were located on the surface of mesoporous nanorods obtained by hydrolysis polycondensation of bis(triethoxysilyl)ethylene, whereas encapsulation occurred with bis(triethoxysilyl)ethane. The later nanoparticles NaYF4: Yb3+-Er3+@Ethane or BaLuF5: Yb3+-Er3+@Ethane were promising for applications with cancer cell imaging or X-ray-computed tomography respectively.


Assuntos
Nanopartículas/química , Compostos de Organossilício/química , Sistemas de Liberação de Medicamentos/métodos , Érbio/química , Etano/química , Fluoretos/química , Hidrólise , Nanomedicina/métodos , Nanotubos/química , Tecnologia Farmacêutica/métodos , Itérbio/química , Ítrio/química
9.
Nanoscale ; 11(45): 22079-22088, 2019 Nov 21.
Artigo em Inglês | MEDLINE | ID: mdl-31720650

RESUMO

Lanthanide-doped nanoparticles have long been stereotyped for optical luminescence bioimaging. However, they are known to be unable to produce therapeutic abilities. Here, we describe a lanthanide-based theranostic agent, namely, prussian blue (PB)-coated NaErF4@NaYF4@NaNdF4 core/shell/shell nanocrystals encapsulated in a phospholipid PEG micelle (PEG-CSS@PB), which showed switched imaging and hyperthermia abilities under distinct near infrared (NIR) light activation. The erbium (Er3+)-enriched inner core nanocrystals (NaErF4) enabled the emission of tissue-penetrating luminescence (1525 nm) in the second biological window (NIR-II, 1000-1700 nm), which endowed high-resolution optical imaging of the blood vessels and tumors under ∼980 nm excitation. High neodymium (Nd3+) concentrations in the epitaxial outer NaNdF4 shell introduced maximum cross relaxation processes that converted the absorbed NIR light (∼808 nm) into heat at high efficiencies, thus providing abilities for photothermal therapy (PTT). Importantly, the coated Prussian blue (PB) increased light absorption by about 10-fold compared to the composite free of PB, thus entailing a high light-to-heat conversion efficiency of ∼50.5%. This commensurated with that of well-established gold nanorods. As a result, the PEG-CSS@PB nanoparticles with MTT-determined low toxicities resulted in ∼80% death of HeLa cells at a dose of 600 µg mL-1 under 808 nm laser irradiance (1 W cm-2) for 10 min. Moreover, utilizing the same light dose, a single PTT treatment in tumor-bearing BALB/c mice shrunk the tumor size by ∼12-fold compared to the tumors without treatment. Our results, here, constituted a solid step forward to entitle lanthanide-based nanoparticles as theranostic agents in nanomedicine studies.


Assuntos
Materiais Revestidos Biocompatíveis , Ferrocianetos , Hipertermia Induzida , Nanopartículas , Neoplasias Experimentais , Imagem Óptica , Fototerapia , Animais , Materiais Revestidos Biocompatíveis/química , Materiais Revestidos Biocompatíveis/farmacologia , Feminino , Ferrocianetos/química , Ferrocianetos/farmacologia , Células HeLa , Humanos , Camundongos , Camundongos Endogâmicos BALB C , Nanopartículas/química , Nanopartículas/uso terapêutico , Neodímio/química , Neodímio/farmacologia , Neoplasias Experimentais/diagnóstico por imagem , Neoplasias Experimentais/terapia , Ítrio/química , Ítrio/farmacologia
10.
ACS Appl Mater Interfaces ; 11(46): 42943-42955, 2019 Nov 20.
Artigo em Inglês | MEDLINE | ID: mdl-31647216

RESUMO

The capability to detect bacteria at a low cell density is critical to prevent the delay in therapeutic intervention and to avoid the emergence of antibiotic-resistant species. Till date, significant advancement has been made to develop a sensing platform for rapid and reliable bacterial detection. However, critical requirements, that is, limit of detection, fast time of response, ultrasensitivity with high reproducibility, and the ability to distinguish between bacterial strains are yet to be met within a single sensing platform. In this contribution, we present a novel label-free sensor based on pH-sensitive fluorescent yttrium-doped carbon nanoparticles (YCNPs) embedded in agarose that can rapidly and accurately detect and discriminate pathogens in real time. The developed sensor matrix presented pH-triggered aggregation-induced emission quenching of YCNPs in a wide pH range. When the pH decreased from 10.0 to 4.0, the fluorescence of the matrix decreased linearly (R2 = 0.9229). The sensor 's high sensitivity in a physiologically relevant pH range enables the monitoring of the presence of live pathogens to single-cell resolution. In addition, the 3D matrix sensor showed low cytotoxicity and long stability (>30 days). Besides, the YCNP platform is stable for several hours (5 h) in a complex medium and does not alter the bacterial activities, allowing real-time monitoring of bacterial growth with a small sample volume (100 µL) and rapid response time (25 min). Furthermore, using machine learning-assisted tools, different bacterial strains with various cell densities were discriminated with an accuracy of almost 100%. Moreover, blends of pathogens and a real-world sample can also be identified accurately, thus enabling the sensor to provide fast and reliable pathogen information for clinical decisions and allowing continuous monitoring of infectious disease trends.


Assuntos
Carbono/química , Nanopartículas/química , Streptococcus mutans , Ítrio/química , Concentração de Íons de Hidrogênio , Limite de Detecção , Nanopartículas/ultraestrutura , Streptococcus mutans/metabolismo , Streptococcus mutans/ultraestrutura
11.
Nanoscale ; 11(43): 20598-20613, 2019 Nov 21.
Artigo em Inglês | MEDLINE | ID: mdl-31641713

RESUMO

Herein, we reported the fabrication of novel peptide-conjugated ligand-targeted nanoliposomes (LTLs) for chemo-photodynamic therapy against HER2-positive breast cancer. The LTL core was utilized for encapsulating doxorubicin (DOX) for chemotherapy, and methylene blue (MB) attached NaYF4:Yb,Er upconversion nanoparticles (UCNPs) for NIR-activated bioimaging and leveraging its visible emission for photoexciting MB for enhanced photodynamic therapy (PDT). The specificity of our LTLs was achieved by conjugating a newly discovered anti-HER2 peptide screened from a phage display peptide library. The high selectivity of the peptide-conjugated LTLs was confirmed by confocal imaging of SKBR-3 (HER2-positive) and MCF-7 (HER2-negative) breast cancer cell lines, illustrating its target-specific nature. The energy transfer from UCNPs to MB was verified, thus enabling the generation of reactive oxygen species upon activation with a 975 nm laser source (0.60 W cm-2) under 5 min continuous excitation. A significant decline in the cell viability by 95% was observed using chemo-photodynamic combinational therapy, whereas for chemo-drug alone and PDT alone, the cell proliferation declined by 77% and 84%, respectively. Furthermore, we demonstrated an improved uptake of the LTLs inside a 3D model of SKBR-3 tumor spheroids, where the spheroid cell viability was suppressed by 66% after the use of combinational therapy. Thus, our results suggest great prospective use of theranostic LTLs for breast cancer management.


Assuntos
Raios Infravermelhos , Lipossomos/química , Nanopartículas de Magnetita/química , Peptídeos/metabolismo , Receptor ErbB-2/metabolismo , Apoptose/efeitos dos fármacos , Neoplasias da Mama/tratamento farmacológico , Neoplasias da Mama/metabolismo , Neoplasias da Mama/patologia , Linhagem Celular Tumoral , Érbio/química , Feminino , Fluoretos/química , Humanos , Azul de Metileno/química , Azul de Metileno/farmacologia , Azul de Metileno/uso terapêutico , Microscopia Confocal , Nanoestruturas/química , Biblioteca de Peptídeos , Peptídeos/química , Fotoquimioterapia , Fármacos Fotossensibilizantes/química , Fármacos Fotossensibilizantes/farmacologia , Fármacos Fotossensibilizantes/uso terapêutico , Espécies Reativas de Oxigênio/metabolismo , Receptor ErbB-2/imunologia , Ítrio/química
12.
ACS Appl Mater Interfaces ; 11(42): 38459-38466, 2019 Oct 23.
Artigo em Inglês | MEDLINE | ID: mdl-31593426

RESUMO

Upconversion nanoparticles (UCNPs) have become competitive materials for bioanalysis, bioimaging, and early diagnosis of diseases, especially cancers. However, traditional upconversion luminescence (UCL) nanosensors are often challenged with complicated covalent modification and relatively poor stability. As efficient energy acceptors in the luminescence resonance energy-transfer (LRET) process, organic dyes exhibit unique advantages such as easy modification and stable property. Herein, a simple and universal bioplatform is constructed for in situ imaging and quantitation of intracellular microRNA-21 (miR-21) using dual-acceptor-based upconversion nanoprobes with enhanced quenching efficiency. In this assay, UCNPs with core-shell structures are synthesized, in which the emitting ions are confined in the shell to take the energy donors and acceptors in close proximity. The complementary DNA (cDNA) that can specifically recognize target miR-21 is labeled with organic dyes TAMRA and black hole quencher as dual acceptors and easily assembled on UCNPs via electrostatic adsorption. Compared with only one acceptor for LRET, two dyes quench more luminescence of UCNPs (>60%), which thus reduce the background and improve the sensitivity. With the enhanced quenching efficiency and simple assembly process, the proposed system is readily applied to in situ imaging of miR-21 in different cancer cells, which further achieves quantification of miR-21 in MCF-7 cells. Therefore, our proposed dual-acceptor-based upconversion nanoplatform opens up new opportunities for sensitive analysis of miRNA and provides potential applications in biomedical and clinical research.


Assuntos
MicroRNAs/metabolismo , Nanopartículas/química , Animais , DNA Complementar/metabolismo , Transferência Ressonante de Energia de Fluorescência , Fluoretos/química , Células HeLa , Humanos , Células MCF-7 , Camundongos , MicroRNAs/química , Microscopia Confocal , Células NIH 3T3 , Ítrio/química
13.
Int J Nanomedicine ; 14: 7003-7016, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31564862

RESUMO

Background: Yttria-stabilized zirconia (Y2O3/ZrO2) nanoparticles are one of the important nanoparticles extensively used in manufacturing of plastics, textiles, catalyst, etc. Still, the cytotoxic and apoptotic effects of yttria-stabilized zirconia nanoparticles have not been well identified on human skin keratinocyte (HaCaT) cells. Therefore, in this study, we have designed to examine the cytotoxic potential of yttria-stabilized zirconia nanoparticles in HaCaT cells. Methods: Prior to treatment, the yttria-stabilized zirconia nanoparticles were characterized by using different advanced instruments viz. dynamic light scattering (DLS), scanning electron microscope (SEM) and transmission electron microscope (TEM). Cell viability of HaCaT cells was measured by using MTS and NRU assays and viability of cells was reduced in a dose- and time-dependent manner. Results: Reduction in the viability of cells was correlated with the rise of reactive oxygen species generation, increased caspase-3, mitochondria membrane potential and evidence of DNA strand breakage. These were consistent with the possibility that mitochondria damage can play a significant role in the cytotoxic response. Moreover, the activity of oxidative enzymes such as lipid peroxide (LPO) was increased and glutathione was reduced in HaCaT cells exposed with yttria-stabilized zirconia nanoparticles. It is also important to indicate that HaCaT cells appear to be more susceptible to yttria-stabilized zirconia nanoparticles exposure after 24 hrs. Conclusion: This result provides a dose- and time-dependent apoptosis and genotoxicity of yttria-stabilized zirconia nanoparticles in HaCaT cells.


Assuntos
Apoptose , Dano ao DNA , Células Epiteliais/citologia , Nanopartículas Metálicas/química , Pele/citologia , Ítrio/química , Zircônio/química , Acetilcisteína/farmacologia , Apoptose/efeitos dos fármacos , Linhagem Celular , Forma Celular/efeitos dos fármacos , Sobrevivência Celular/efeitos dos fármacos , Quebras de DNA de Cadeia Dupla/efeitos dos fármacos , Fragmentação do DNA/efeitos dos fármacos , Células Epiteliais/metabolismo , Glutationa/metabolismo , Humanos , Membranas Intracelulares/efeitos dos fármacos , Membranas Intracelulares/metabolismo , Lisossomos/efeitos dos fármacos , Lisossomos/metabolismo , Potencial da Membrana Mitocondrial/efeitos dos fármacos , Nanopartículas Metálicas/ultraestrutura , Estresse Oxidativo/efeitos dos fármacos , Espécies Reativas de Oxigênio/metabolismo
14.
Chem Commun (Camb) ; 55(77): 11511-11514, 2019 Sep 24.
Artigo em Inglês | MEDLINE | ID: mdl-31490471

RESUMO

A short metallofullere-peapod of Y2@C79N⊂[4]CHBC was constructed. The strong confinement effect from the large π-extended [4]CHBC nanoring induces molecular orientation of the wrapped Y2@C79N, which can be sensed by a Y2@C79N spin probe. The low susceptibility of the spin phase memory time (Tm) for the Y2@C79N spin was also found in a confined space.


Assuntos
Complexos de Coordenação/química , Fulerenos/química , Hidrocarbonetos Cíclicos/química , Marcadores de Spin , Ítrio/química , Compostos Aza/química , Teoria da Densidade Funcional , Conformação Molecular , Transição de Fase , Temperatura , Termodinâmica
15.
Colloids Surf B Biointerfaces ; 183: 110436, 2019 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-31421402

RESUMO

The presence of hazardous, radioactive, and rare earth metal such as yttrium (Y3+) in water poses a serious health concern to the public health, thus, exploring novel Y3+-binding molecules and colorimetric indicators are desired. Chlortetracycline (CTC)-functionalized silver nanoparticles (AgNPs-CTC) were synthesized, purified by centrifugation and then characterized by UV-vis spectroscopy, XPS, XRD, and HR-TEM. Functionalization of AgNPs with CTC molecules enabled the rapid and sensitive detection of trivalent yttrium ion (Y3+). A decrease in the intensity of the original surface plasmon resonance peak at 420 nm was observed within the fraction of a min, with the simultaneous appearance of a new peak at a longer wavelength (540 nm); thus, a novel colorimetric and ratiometric absorbance probe was achieved. The free-O-containing moieties of CTC on the AgNPs surface coordinate with Y3+. Thus, CTC molecules led to the bridging of the AgNPs and subsequent aggregation. A good linear relationship (R2 = 0.933) in the range of 18 to 243 nM for Y3+ was observed, and the limit of detection (LOD) for ratiometric results was approximately 57.7 nM. The AgNPs-CTC sensor exhibited better colorimetric performance in terms of excellent sensitivity, LOD, and rapid formation of the AgNPs-CTC complex towards Y3+. The Y3+ spiked water samples from different sources and fetal bovine serum suggest that the developed method is practically useful and essentially portable for on-site monitoring. The AgNPs-CTC sensor can be also applied as a common colorimetric indicator for the detection of trace levels of Y3+ and lanthanides.


Assuntos
Clortetraciclina/química , Colorimetria/métodos , Nanopartículas Metálicas/química , Prata/química , Espectrofotometria Ultravioleta/métodos , Ítrio/química , Elementos da Série dos Lantanídeos/análise , Elementos da Série dos Lantanídeos/química , Fenômenos Mecânicos , Nanopartículas Metálicas/ultraestrutura , Microscopia Eletrônica de Transmissão , Reprodutibilidade dos Testes , Ressonância de Plasmônio de Superfície , Difração de Raios X , Ítrio/análise
16.
Anal Chim Acta ; 1079: 200-206, 2019 Nov 04.
Artigo em Inglês | MEDLINE | ID: mdl-31387712

RESUMO

Arginine is an important amino acid in humankind bodies and is of essential clinical significance. This paper presents a novel bioprobe based on fluorescence resonance energy transfer (FRET), which can be used to detect arginine efficiently and economically. In this bioprobe system, positively charged up-conversion phosphor NaYF4 (NYF) acts as energy donor, and negatively charged gold nanoparticle (AuNP) acts as energy acceptor. The oppositely charged donor and acceptor come into close proximity through electrostatic attraction effect, which results in the occurrence of FRET between NYF and AuNP. The FRET process is thus in the "on" state, meanwhile the system is in the "off" state, and the emitting light of NYF quenched. When positively charged arginine is added into the system, the guanidyl of arginine binds to AuNP and leads to the negatively charged AuNP becomes positively charged one, and the AuNP separates from NYF because of the electrostatic repulsion. The FRET process is blocked and the system switches to the "on" state because the distance between NYF and AuNP becomes longer. In the "on" state, the intensity of the restored emitting light is proportional to the concentration of arginine. This approach brings a good linear relationship between the fluorescence intensity and the concentration of arginine in the concentration range of 14.42-115.04 µM. The limit of detection is as low as 2.9 µM. A new method for quantitative determination of arginine by just measuring the fluorescence intensity of the system is established.


Assuntos
Arginina/sangue , Técnicas Biossensoriais/métodos , Fluoretos/química , Nanopartículas Metálicas/química , Ítrio/química , Érbio/química , Fluorescência , Transferência Ressonante de Energia de Fluorescência/métodos , Ouro/química , Humanos , Limite de Detecção , Espectrometria de Fluorescência/métodos , Itérbio/química
17.
Dalton Trans ; 48(34): 12850-12857, 2019 Sep 14.
Artigo em Inglês | MEDLINE | ID: mdl-31393486

RESUMO

Even though various theranostic agents have been exploited for effective cancer therapy over the years, appropriate design and fabrication of theranostic agents with simple composition, convenient preparation, high theranostic efficiency and minimal side effects on non-cancer cells are still urgently needed. Herein, multifunctional NaYF4:Yb,Er@polyelectrolyte (PE3)@Fe3O4 nanocomposites, with upconversion luminescence, superparamagnetism and photothermal performance, are prepared by a layer-by-layer self-assembly technique. Compared with Fe3O4 nanoparticles (NPs), the nanocomposites exhibited nearly 2-fold strong absorption at 808 nm, and thus resulted in an enhanced near-infrared photothermal effect. With the assistance of an external magnetic field, a high sensitivity of upconversion fluorescence imaging and a low cancer cell viability of 13.9% were achieved under 808 nm laser irradiation. It is expected that multifunctional NaYF4:Yb,Er@PE3@Fe3O4 nanocomposites would pave the way toward promoting the clinical applications of theranostic nanomaterials.


Assuntos
Érbio/química , Campos Magnéticos , Nanocompostos , Imagem Óptica/métodos , Fototerapia/métodos , Itérbio/química , Ítrio/química , Animais , Linhagem Celular Tumoral , Luminescência , Camundongos
18.
Int J Nanomedicine ; 14: 4319-4331, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31354263

RESUMO

Objective: The study aimed to synthesize superparamagnetic NaYF4:Yb,Er@PE3@Fe3O4 upconversion nanoprobes and to study their photothermal effects for the treatment of malignant melanoma. Methods: Morphological characteristics of the synthesized nanoprobes were examined by scanning electron microscopy. Their biocompatibility and biodistribution profiles were assessed through blood routine/biochemistry tests and the inductively coupled plasma/optical emission spectrometry-based analysis of tissue metal elements. Their photothermal conversion efficiency and their potential as contrast agents for upconversion luminescence (UCL)/magnetic resonance imaging (MRI) dual-modal imaging were tested. Efficacy in photothermal therapy, which was achieved by combining nanoprobes with near-infrared (NIR) irradiation, was evaluated in both A375 cell line and BALB/c mice models. The underlying mechanisms were interrogated by molecular approaches including the MTT assay, flow cytometry, semiquantitative PCR, western blot, and immunohistochemistry. Results: 1) Our synthesized NaYF4:Yb,Er@PE3@Fe3O4 nanoprobes exhibited a uniform cubic morphology with a diameter of ~50 nm. Subcutaneous administration led to no severe, long-lasting adverse effects in mice, possibly due to complete removal of these nanomaterials within one month. 2) Our nanoprobes possessed superior photothermal conversion efficiency and strong contrasting effects during UCL/MRI dual-modal imaging, corroborating their applications in imaging-guided photothermal therapy. 3) Combinatorial treatment of these nanoprobes with NIR irradiation induced profound apoptosis/necrosis in A375 cells. Similarly, the same treatment modality led to strong therapeutic effects in BALB/c mice implanted with A375 tumor xenografts. Mechanistic studies suggested an involvement of heat shock protein 70 in mediating the observed antitumor effects of our nanoprobes. Conclusion: Our study describes a convenient method to synthesize a new type of superparamagnetic upconversion nanoprobes, which possess high biocompatibility and can be used in imaging-guided photothermal therapy for the treatment of malignant melanoma. Importantly, our findings will promote clinical applications of NaYF4:Yb,Er@PE3@Fe3O4 as novel theranostic agents in treating melanoma and many other tumors.


Assuntos
Érbio/química , Fluoretos/química , Hipertermia Induzida , Nanopartículas de Magnetita/uso terapêutico , Melanoma/terapia , Fototerapia , Ítrio/química , Animais , Linhagem Celular Tumoral , Proteínas de Choque Térmico HSP70/metabolismo , Humanos , Raios Infravermelhos , Imagem por Ressonância Magnética/métodos , Nanopartículas de Magnetita/ultraestrutura , Melanoma/patologia , Camundongos Endogâmicos BALB C , Camundongos Nus , Distribuição Tecidual , Carga Tumoral
19.
Mater Sci Eng C Mater Biol Appl ; 103: 109801, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31349469

RESUMO

In situ tissue engineering is emerging as a novel approach in tissue engineering to repair damaged tissues by boosting the natural ability of the body to heal itself. This can be achieved by providing suitable signals and scaffolds that can augment cell migration, cell adhesion on the scaffolds and proliferation of endogenous cells that facilitate the repair. Lack of appropriate cell proliferation and angiogenesis are among the major issues associated with the limited success of in situ tissue engineering during in vivo studies. Exploitation of metal oxide nanoparticles such as yttrium oxide (Y2O3) nanoparticles may open new horizons in in situ tissue engineering by providing cues that facilitate cell proliferation and angiogenesis in the scaffolds. In this context, Y2O3 nanoparticles were synthesized and incorporated in polycaprolactone (PCL) scaffolds to enhance the cell proliferation and angiogenic properties. An optimum amount of Y2O3-containing scaffolds (1% w/w) promoted the proliferation of fibroblasts (L-929) and osteoblast-like cells (UMR-106). Results of chorioallantoic membrane (CAM) assay and the subcutaneous implantation studies in rats demonstrated the angiogenic potential of the scaffolds loaded with Y2O3 nanoparticles. Gene expression study demonstrated that the presence of Y2O3 in the scaffolds can upregulate the expression of cell proliferation and angiogenesis related biomolecules such as VEGF and EGFR. Obtained results demonstrated that Y2O3 nanoparticles can perform a vital role in tissue engineering scaffolds to promote cell proliferation and angiogenesis.


Assuntos
Nanopartículas Metálicas/química , Engenharia Tecidual , Tecidos Suporte/química , Ítrio/química , Animais , Adesão Celular/efeitos dos fármacos , Linhagem Celular , Proliferação de Células/efeitos dos fármacos , Expressão Gênica/efeitos dos fármacos , Nanopartículas Metálicas/toxicidade , Camundongos , Neovascularização Fisiológica/efeitos dos fármacos , Poliésteres/química , Resistência à Tração , Fator A de Crescimento do Endotélio Vascular/genética , Fator A de Crescimento do Endotélio Vascular/metabolismo
20.
Luminescence ; 34(8): 846-853, 2019 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-31297958

RESUMO

Rare-earth ions play an important role in eco-friendly solid-state lighting for the lighting industry. In the present study we were interested in Eu3+ ion-doped inorganic phosphors for near ultraviolet (UV) excited light-emitting diode (LED) applications. Eu3+ ion-activated SrYAl3 O7 phosphors were prepared using a solution combustion route at 550°C. Photoluminescence characterization of SrYAl3 O7 :Eu3+ phosphors showed a 612 nm emission peak in the red region of the spectrum due to the 5 D0 →7 F2 transition of Eu3+ ions under excitation at 395 nm in the near-UV region and at the 466 nm blue excitation wavelength. These red and blue emissions are supported for white light generation for LED lighting. Structure, bonding between each element of the sample and morphology of the sample were analysed using X-ray diffraction (XRD) and scanning electron microscopy (SEM), which showed that the samples were crystallized in a well known structure. The phosphor was irradiated with a 60 Co-γ (gamma) source at a dose rate of 7.2 kGy/h. Thermoluminescence (TL) studies of these Eu3+ -doped SrYAl3 O7 phosphors were performed using a Nucleonix TL 1009I TL reader. Trapping parameters of this phosphor such as activation energy (E), order of kinetics (b) and frequency factor (s) were calculated using Chen's peak shape method, the initial rise method and Ilich's method.


Assuntos
Substâncias Luminescentes/química , Medições Luminescentes , Alumínio/química , Európio/química , Substâncias Luminescentes/síntese química , Oxigênio/química , Tamanho da Partícula , Estrôncio/química , Propriedades de Superfície , Ítrio/química
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA