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1.
Int J Nanomedicine ; 14: 9631-9645, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31824156

RESUMO

Background: Photothermal therapy (PTT) has great potential in the clinical treatment of tumors. However, most photothermal materials are difficult to apply due to their insufficient photothermal conversion efficiencies (PCEs), poor photostabilities and short circulation times. Furthermore, tumor recurrence is likely to occur using PTT only. In the present study, we prepared cyclo (Arg-Gly-Asp-d-Phe-Cys) [c(RGD)] conjugated doxorubicin (DOX)-loaded Fe3O4@polydopamine (PDA) nanoparticles to develop a multifunctional-targeted nanocomplex for integrated tumor diagnosis and treatment. Materials and methods: Cytotoxicity of Fe3O4@PDA-PEG-cRGD-DOX against HCT-116 cells was determined by cck-8 assay. Cellular uptake was measured by confocal laser scanning microscope (CLSM). Pharmacokinetic performance of DOX was evaluated to compare the differences between free DOX and DOX in nanocarrier. Performance in magnetic resonance imaging (MRI) and antitumor activity of complex nanoparticles were evaluated in tumor-bearing nude mice. Results: Fe3O4@PDA-PEG-cRGD-DOX has a particle size of 200-300 nm and a zeta potential of 22.7 mV. Further studies in vitro and in vivo demonstrated their excellent capacity to target tumor cells and promote drug internalization, and significantly higher cytotoxicity with respect to that seen in a control group was shown for the nanoparticles. In addition, they have good thermal stability, photothermal conversion efficiencies (PCEs) and pH responsiveness, releasing more DOX in a mildly acidic environment, which is very conducive to their chemotherapeutic effectiveness in the tumor microenvironment. Fe3O4@PDA-PEG-cRGD-DOX NPs were used in a subcutaneous xenograft tumor model of nude mouse HCT-116 cells showed clear signal contrast in T2-weighted images and effective anti-tumor chemo-photothermal therapy under NIR irradiation. Conclusion: According to our results, Fe3O4@PDA-PEG-cRGD-DOX had a satisfactory antitumor effect on colon cancer in nude mice and could be further developed as a potential integrated platform for the diagnosis and treatment of cancer to improve its antitumor activity against colon cancer.

2.
Biomaterials ; 222: 119442, 2019 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-31491561

RESUMO

Polyelectrolyte modified iron oxide nanoparticles have great potential applications for clinical magnetic resonance imaging (MRI) and anemia treatments, however, possible associated heart toxicity is rarely reported. Here, polyacrylic acid (PAA)-coated Fe3O4 nanoparticles (PION) were synthesized and lethal reactions appeared when it was applied in vivo. The investigation of underlying mechanism showed that PION could break electrolyte balance and further resulted in serious heart failure, which was observed under color doppler ultrasound and dynamic vector blood flow technique. The results demonstrated that PION had a strong absorption tendency for divalent ions and the maximum tolerated dose (MTD) was lower than 100 mg/kg. From electrocardiography (ECG), PION presented an obvious impact on CaV1.2 ion channel, which leading to fatal arrhythmia. An appropriate solution for preventing this deadly effect was pre-chelation Ca2+ (n (Ca): n (COOH) = 3: 8) to PION (PION-Ca), which displayed much higher cardiac and electrophysiological safety when sealing the binding point of divalent cation ions with PAA. The injection in Beagle dogs further confirmed the safety of PION-Ca. This study explored the mechanism and offered a solution for cardiac toxicity induced by PAA-coated nanoparticles, which guides for enhancing the safety of such polyelectrolyte decorated nanoparticles and provides assurance for clinical applications.

3.
BMC Med Imaging ; 19(1): 55, 2019 07 12.
Artigo em Inglês | MEDLINE | ID: mdl-31299927

RESUMO

BACKGROUND: To determine the effect of region of interest (ROI) on tumor's apparent diffusion coefficient (ADC) and interobserver variability in thyroid nodules. METHODS: Thirty-three individuals with 45 pathologically-confirmed thyroid nodules were assessed by preoperative diffusion-weighted imaging (DWI) with b values of 0 and 400 s/mm2, respectively. Two readers evaluated the ADC values of lesions based on three ROI techniques: whole-volume, single-slice and small solid-sample groups. Interobserver variability was analyzed for all ROI techniques, and the mean ADCs of benign and cancerous thyroid nodules were compared. RESULTS: For the mean ADCs of non-cancerous thyroid nodules, average differences and limits of agreement (LOAs) between readers were 0.00 [- 0.17-0.17] × 10- 3 mm2/s for whole-volume ROI (ICC = 0.967), 0.00 [- 0.26-0.26] × 10- 3 mm2/s for single-slice ROI (ICC = 0.932) and - 0.02 [- 0.38-0.41] × 10- 3 mm2/s for small solid-sample ROI (ICC = 0.823). For the mean ADCs of cancerous thyroid nodules, average differences and LOAs between readers were - 0.05 [- 0.23-0.13] × 10- 3 mm2/s (ICC = 0.885), 0.01 [- 0.23-0.25] × 10- 3 mm2/s (ICC = 0.839) and - 0.07 [- 0.52-0.39] × 10- 3 mm2/s (ICC = 0.579) for the three ROI methods, respectively. The mean ADC values were more scattered in the small solid-sample ROI group in comparison with the whole-volume and single-slice groups, in noncancerous and cancerous specimens. Of all three ROI techniques, whole-volume ROI-determined ADC had the highest combined sensitivity (80.0%), specificity (88.3%) and Youden index (0.683), with a cut-off of 1.84 × 10- 3 mm2/s. CONCLUSIONS: The ROI method overtly affects ADC measurements in benign and cancerous thyroid nodules. Small solid-sample ROI yielded the worst interobserver variability of average ADC measurements.


Assuntos
Imagem de Difusão por Ressonância Magnética/métodos , Nódulo da Glândula Tireoide/diagnóstico por imagem , Adulto , Idoso , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Variações Dependentes do Observador , Reprodutibilidade dos Testes , Sensibilidade e Especificidade
4.
ACS Appl Mater Interfaces ; 4(12): 6479-86, 2012 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-23151093

RESUMO

Nanoclusters of superparamagnetic iron oxide nanoparticles (SPION) are developed for liver-specific magnetic resonance imaging (MRI) by a unique synthesis route. The process is efficient, environmentally benign, and straight forward within five minutes. The clustering effect is triggered in the presence of bovine serum albumin (BSA) aqueous phase under ultrasonication condition. The hydrophobic SPION are densely self-assembled into BSA/SPION hybrid nanoclusters with a uniform size of ~86 nm. The as-prepared BSA/SPION hybrid nanoclusters are found to be biocompatible and stable. They exhibit high transverse relaxivity and longitudinal relaxivity in water (r(2) and r(1) values are 600.8 and 4.3 s(-1) per mM of Fe(3+), respectively). In vivo T(2)-weighted MRI shows excellent enhancement in liver with an imaging time-window up to 48 h. In vivo biodistribution study indicates a gradual excretion of the nanoclusters via hepatobiliary (HB) processing. No toxicity is observed in the in vivo and ex vivo experiments. The BSA/SPION hybrid nanoclusters present great potential in MRI as the liver-specific contrast agents (CAs).


Assuntos
Fígado/metabolismo , Imagem por Ressonância Magnética/métodos , Nanoestruturas , Soroalbumina Bovina/química , Ultrassom , Animais , Camundongos , Microscopia Eletrônica de Transmissão , Distribuição Tecidual
5.
Zhonghua Gan Zang Bing Za Zhi ; 14(8): 590-6, 2006 Aug.
Artigo em Chinês | MEDLINE | ID: mdl-16938171

RESUMO

OBJECTIVE: To estimate the correlations between functional MRI (fMRI) parameters and the severity of chronic liver lesions of hepatitis B patients. METHODS: 47 hepatitis B patients [6 with chronic hepatitis, 41 with cirrhosis (14 with Child-Pugh class A cirrhosis; 12 with class B cirrhosis; and 15 with class C cirrhosis)] and 10 normal volunteers, referred for measurements of apparent diffusion coefficient (ADC) values of the liver, perfusion imaging parameters, portal flow parameters and serum markers of hepatic fibrosis were included in the study. Diffusion-weighted imaging (DWI) with different b values and b value remainder was performed. Time to peak (TP), maximum slope of increase (MSI) and distribution volume (DV) were measured with dynamic contrast material-enhanced MR imaging. Portal velocity and portal flow with phase contrast (PC) were measured. The patients' serum hepatic fibrosis markers, including hyaluronic acid (HA), type-III-procollagen (PC III), laminin (LN) and type-IV-collagen (C IV), were measured and analyzed together with the fMRI results. RESULTS: (1) The mean ADC3 in Child A, B, C cirrhosis patients was significantly lower than that in the controls (P < 0.05 in Child A, and P < 0.05 in Child B). (2) There was a significant increase of time to peak and a decrease of maximum slope of increase (P < 0.01) in the Child A, B, C patients than in the normal controls. (3) There was a significant decrease in portal velocity in cirrhotic patients as compared to that of the controls and chronic hepatitis patients (P < 0.01). (4) The mean HA in Child A, B, C cirrhosis patients was significantly higher than that in chronic hepatitis patients and in the controls (P < 0.01); The mean LN in Child A, B, C cirrhosis was also significantly higher than that in chronic hepatitis patients and in normal controls (P < 0.01); The mean PC III in Child A, B, C cirrhosis was significantly higher than that in the normal controls (P < 0.01). CONCLUSION: fMRI parameters can reflect some changes of the livers, therefore fMRI parameters are of value in clinical diagnosis and treatment of chronic hepatitis B patients.


Assuntos
Hepatite B Crônica/patologia , Cirrose Hepática/patologia , Imagem por Ressonância Magnética , Adulto , Idoso , Feminino , Hepatite B/complicações , Hepatite B Crônica/diagnóstico , Humanos , Cirrose Hepática/diagnóstico , Cirrose Hepática/etiologia , Masculino , Pessoa de Meia-Idade
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