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1.
Spectrochim Acta A Mol Biomol Spectrosc ; 224: 117435, 2020 Jan 05.
Artigo em Inglês | MEDLINE | ID: mdl-31400745

RESUMO

A novel two-photon pH probe, 3-benzimidazole-7-hydroxycoumarin (BHC), was designed and synthesized based on the structures of hydroxycoumarin and benzimidazole. BHC showed good linearity in the pH ranges of 3.30-5.40 (pKa = 4.20) and 6.50-8.30 (pKa = 7.20) at a maximum emission wavelength of 480 nm. BHC in acidic and alkaline media could be distinguished by an obvious spectral shift of the maximum absorption wavelength from 390 nm to 420 nm. In addition, BHC was well localized to mitochondria and successfully applied to one-photon and two-photon imaging of pH changes in the mitochondria of HeLa cells. The findings presented herein suggest that BHC can serve as an excellent fluorescent probe for selectively sensing mitochondrial pH changes with remarkable photostability and low cytotoxicity.


Assuntos
Benzimidazóis/química , Cumarínicos/química , Corantes Fluorescentes/química , Microscopia de Fluorescência por Excitação Multifotônica/métodos , Mitocôndrias , Umbeliferonas/química , Células HeLa , Humanos , Concentração de Íons de Hidrogênio , Mitocôndrias/química , Mitocôndrias/fisiologia
2.
Spectrochim Acta A Mol Biomol Spectrosc ; 224: 117310, 2020 Jan 05.
Artigo em Inglês | MEDLINE | ID: mdl-31326856

RESUMO

The detection of viscosity is of great significance for medical research. Herein, we have developed a two-photon fluorescent probe CB-V for monitoring micro-viscosity changes. The fluorescence emission intensity of CB-V increased 9.6-fold from methanol to glycerol exhibiting an excellent fluorescence response. With excellent properties of CB-V, monitoring the viscosity variations has been achieved not only in living cells but also in zebra fish and mice.


Assuntos
Corantes Fluorescentes/química , Microscopia de Fluorescência por Excitação Multifotônica/métodos , Viscosidade , Animais , Corantes Fluorescentes/análise , Células HeLa , Humanos , Camundongos , Imagem Corporal Total , Peixe-Zebra
4.
Chem Commun (Camb) ; 55(86): 12912-12915, 2019 Oct 24.
Artigo em Inglês | MEDLINE | ID: mdl-31593207

RESUMO

Alcohol-induced liver injury has been a terrible threat to human health and life. The relationship between HClO and the process is unclear. Thus, a ratiometric two-photon fluorescent probe for HClO was deliberately constructed and revealed the generation of HClO in the alcohol-induced liver injury process for the first time.


Assuntos
Doença Hepática Induzida por Substâncias e Drogas/diagnóstico por imagem , Corantes Fluorescentes/química , Ácido Hipocloroso/análise , Animais , Doença Hepática Induzida por Substâncias e Drogas/etiologia , Etanol/toxicidade , Células HeLa , Humanos , Ácido Hipocloroso/metabolismo , Camundongos , Microscopia de Fluorescência por Excitação Multifotônica , Imagem Óptica , Peixe-Zebra
5.
Nat Commun ; 10(1): 4483, 2019 10 02.
Artigo em Inglês | MEDLINE | ID: mdl-31578369

RESUMO

Among optical imaging techniques light sheet fluorescence microscopy is one of the most attractive for capturing high-speed biological dynamics unfolding in three dimensions. The technique is potentially millions of times faster than point-scanning techniques such as two-photon microscopy. However light sheet microscopes are limited by volume scanning rate and/or camera speed. We present speed-optimized Objective Coupled Planar Illumination (OCPI) microscopy, a fast light sheet technique that avoids compromising image quality or photon efficiency. Our fast scan system supports 40 Hz imaging of 700 µm-thick volumes if camera speed is sufficient. We also address the camera speed limitation by introducing Distributed Planar Imaging (DPI), a scaleable technique that parallelizes image acquisition across cameras. Finally, we demonstrate fast calcium imaging of the larval zebrafish brain and find a heartbeat-induced artifact, removable when the imaging rate exceeds 15 Hz. These advances extend the reach of fluorescence microscopy for monitoring fast processes in large volumes.


Assuntos
Encéfalo/diagnóstico por imagem , Diagnóstico por Imagem/instrumentação , Processamento de Imagem Assistida por Computador/instrumentação , Medições Luminescentes/instrumentação , Microscopia/instrumentação , Animais , Diagnóstico por Imagem/métodos , Processamento de Imagem Assistida por Computador/métodos , Larva , Medições Luminescentes/métodos , Microscopia/métodos , Microscopia Confocal/instrumentação , Microscopia Confocal/métodos , Microscopia de Fluorescência/instrumentação , Microscopia de Fluorescência/métodos , Microscopia de Fluorescência por Excitação Multifotônica/instrumentação , Microscopia de Fluorescência por Excitação Multifotônica/métodos , Reprodutibilidade dos Testes , Peixe-Zebra
6.
Nat Methods ; 16(11): 1119-1122, 2019 11.
Artigo em Inglês | MEDLINE | ID: mdl-31659327

RESUMO

Two-photon microscopy is a mainstay technique for imaging in scattering media and normally provides frame-acquisition rates of ~10-30 Hz. To track high-speed phenomena, we created a two-photon microscope with 400 illumination beams that collectively sample 95,000-211,000 µm2 areas at rates up to 1 kHz. Using this microscope, we visualized microcirculatory flow, fast venous constrictions and neuronal Ca2+ spiking with millisecond-scale timing resolution in the brains of awake mice.


Assuntos
Encéfalo/irrigação sanguínea , Microscopia de Fluorescência por Excitação Multifotônica/métodos , Animais , Cálcio/metabolismo , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Microcirculação , Vigília
7.
Biophys Chem ; 254: 106262, 2019 11.
Artigo em Inglês | MEDLINE | ID: mdl-31514114

RESUMO

The application of nanotechnologies to address biomedical questions is a key strategy for innovation in biomedical research. Among others, a key point consists in the availability of nanotechnologies for monitoring cellular processes in a real-time and label-free approach. Here, we focused on a grating-coupled Surface Plasmon Resonance (GC-SPR) sensor exploiting phase interrogation. This sensor can be integrated in a microfluidic chamber that ensures cell viability and avoids cell stress. We report the calibration of the sensor response as a function of cell number and its application to monitor cell adhesion kinetics as well as cell response to an external stimulus. Our results show that GC-SPR sensors can offer a valuable alternative to prism-coupled or imaging SPR devices, amenable for microfluidic implementation.


Assuntos
Dispositivos Lab-On-A-Chip , Ressonância de Plasmônio de Superfície/métodos , Adesão Celular , Linhagem Celular Tumoral , Sobrevivência Celular , Humanos , Microscopia de Fluorescência por Excitação Multifotônica , Nanoestruturas/química
8.
Adv Mater ; 31(44): e1904447, 2019 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-31523869

RESUMO

Intravital fluorescence imaging of vasculature morphology and dynamics in the brain and in tumors with large penetration depth and high signal-to-background ratio (SBR) is highly desirable for the study and theranostics of vascular-related diseases and cancers. Herein, a highly bright fluorophore (BTPETQ) with long-wavelength absorption and aggregation-induced near-infrared (NIR) emission (maximum at ≈700 nm) is designed for intravital two-photon fluorescence (2PF) imaging of a mouse brain and tumor vasculatures under NIR-II light (1200 nm) excitation. BTPETQ dots fabricated via nanoprecipitation show uniform size of around 42 nm and a high quantum yield of 19 ± 1% in aqueous media. The 2PF imaging of the mouse brain vasculatures labeled by BTPETQ dots reveals a 3D blood vessel network with an ultradeep depth of 924 µm. In addition, BTPETQ dots show enhanced 2PF in tumor vasculatures due to their unique leaky structures, which facilitates the differentiation of normal blood vessels from tumor vessels with high SBR in deep tumor tissues. Moreover, the extravasation and accumulation of BTPETQ dots in deep tumor (more than 900 µm) is visualized under NIR-II excitation. This study highlights the importance of developing NIR-II light excitable efficient NIR fluorophores for in vivo deep tissue and high contrast tumor imaging.


Assuntos
Vasos Sanguíneos/diagnóstico por imagem , Encéfalo/diagnóstico por imagem , Corantes Fluorescentes/química , Microscopia de Fluorescência por Excitação Multifotônica/métodos , Neoplasias/diagnóstico por imagem , Pirróis/química , Pontos Quânticos/química , Tiadiazóis/química , Animais , Encéfalo/irrigação sanguínea , Sobrevivência Celular , Células HeLa , Humanos , Camundongos Endogâmicos BALB C , Neoplasias/irrigação sanguínea , Espectroscopia de Luz Próxima ao Infravermelho , Distribuição Tecidual
9.
Adv Mater ; 31(44): e1904799, 2019 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-31523871

RESUMO

Nonlinear optical microscopy has become a powerful tool in bioimaging research due to its unique capabilities of deep optical sectioning, high-spatial-resolution imaging, and 3D reconstruction of biological specimens. Developing organic fluorescent probes with strong nonlinear optical effects, in particular third-harmonic generation (THG), is promising for exploiting nonlinear microscopic imaging for biomedical applications. Herein, a simple method for preparing organic nanocrystals based on an aggregation-induced emission (AIE) luminogen (DCCN) with bright near-infrared emission is successfully demonstrated. Aggregation-induced nonlinear optical effects, including two-photon fluorescence (2PF), three-photon fluorescence (3PF), and THG, of DCCN are observed in nanoparticles, especially for crystalline nanoparticles. The nanocrystals of DCCN are successfully applied for 2PF microscopy at 1040 nm NIR-II excitation and THG microscopy at 1560 nm NIR-II excitation, respectively, to reconstruct the 3D vasculature of the mouse cerebral vasculature. Impressively, the THG microscopy provides much higher spatial resolution and brightness than the 2PF microscopy and can visualize small vessels with diameters of ≈2.7 µm at the deepest depth of 800 µm in a mouse brain. Thus, this is expected to inspire new insights into the development of advanced AIE materials with multiple nonlinearity, in particular THG, for multimodal nonlinear optical microscopy.


Assuntos
Vasos Sanguíneos/diagnóstico por imagem , Encéfalo/diagnóstico por imagem , Corantes Fluorescentes/química , Microscopia de Fluorescência por Excitação Multifotônica/métodos , Pontos Quânticos/química , Animais , Benzopiranos/química , Encéfalo/irrigação sanguínea , Encéfalo/metabolismo , Carbazóis/química , Teoria da Densidade Funcional , Feminino , Humanos , Camundongos Endogâmicos ICR , Nanopartículas , Nitrilos/química , Espectroscopia de Luz Próxima ao Infravermelho
10.
Chem Commun (Camb) ; 55(81): 12231-12234, 2019 Oct 08.
Artigo em Inglês | MEDLINE | ID: mdl-31553001

RESUMO

The photophysical properties of a new series of fluorenyl porphyrins bearing water-solubilising oligoethyleneglycol chains are described. These biocompatible compounds present very good two-photon absorption and singlet oxygen generation properties, while retaining some fluorescence in water. After testing in vitro on breast cancer cells, some of them were shown to be efficient non-toxic two-photon photosensitisers allowing for fluorescence imaging, thus demonstrating their theranostic potential.


Assuntos
Fluorenos/química , Fotoquimioterapia/métodos , Fármacos Fotossensibilizantes/química , Porfirinas/química , Materiais Biocompatíveis/química , Permeabilidade da Membrana Celular , Sobrevivência Celular/efeitos dos fármacos , Humanos , Raios Infravermelhos , Células MCF-7 , Microscopia de Fluorescência por Excitação Multifotônica/métodos , Estrutura Molecular , Imagem Óptica/métodos , Polietilenoglicóis/química , Oxigênio Singlete/química , Relação Estrutura-Atividade
11.
Nanoscale ; 11(32): 15245-15252, 2019 Aug 15.
Artigo em Inglês | MEDLINE | ID: mdl-31385580

RESUMO

Compared with traditional organic contrast agents, semiconductor nanocrystals (NCs) have unique optical properties that are vital for biological applications with ultrahigh sensitivities, such as long fluorescence lifetime and large multiphoton absorption (MPA). However, the MPA properties and biological applications of chiral-ligand-stabilized semiconductor NCs have scarcely been reported, which seriously hinders their relevant applications. In this work, we report the aqueous phase transfer of CdSe/CdS dot/rod NCs with the use of cysteine molecules, after which the NCs preserve their high fluorescence quantum yield, long lifetime, and efficient circular dichroism. More importantly, the investigated dot/rod NCs show extremely large two- and three-photon absorption action cross-sections in the first and second biological windows, with maximum values of ∼21 000 GM at 800 nm and ∼4.6 × 10-78 cm6 s2 per photon2 at 1300 nm, which are among the largest values reported for water-soluble fluorescent nanoparticles. Interestingly, the dot/rod NCs exhibit a high singlet oxygen generation efficiency of 35%. In addition, for the first time, two-photon fluorescence lifetime imaging and photodynamic therapy of the dot/rod NCs were successfully demonstrated. The performed investigation of the optical properties of these water-soluble CdSe/CdS dot/rod NCs indicates that they are promising candidates for nonlinear biological imaging applications.


Assuntos
Nanopartículas/química , Pontos Quânticos/química , Água/química , Compostos de Cádmio/química , Sobrevivência Celular/efeitos dos fármacos , Sobrevivência Celular/efeitos da radiação , Feminino , Células HeLa , Humanos , Luz , Microscopia de Fluorescência por Excitação Multifotônica , Nanopartículas/uso terapêutico , Nanopartículas/toxicidade , Fotoquimioterapia , Compostos de Selênio/química , Oxigênio Singlete/química , Oxigênio Singlete/metabolismo , Estereoisomerismo , Sulfetos/química , Neoplasias do Colo do Útero/tratamento farmacológico
12.
PLoS Comput Biol ; 15(8): e1007205, 2019 08.
Artigo em Inglês | MEDLINE | ID: mdl-31374071

RESUMO

Variability, stochastic or otherwise, is a central feature of neural activity. Yet the means by which estimates of variation and uncertainty are derived from noisy observations of neural activity is often heuristic, with more weight given to numerical convenience than statistical rigour. For two-photon imaging data, composed of fundamentally probabilistic streams of photon detections, the problem is particularly acute. Here, we present a statistical pipeline for the inference and analysis of neural activity using Gaussian Process regression, applied to two-photon recordings of light-driven activity in ex vivo mouse retina. We demonstrate the flexibility and extensibility of these models, considering cases with non-stationary statistics, driven by complex parametric stimuli, in signal discrimination, hierarchical clustering and other inference tasks. Sparse approximation methods allow these models to be fitted rapidly, permitting them to actively guide the design of light stimulation in the midst of ongoing two-photon experiments.


Assuntos
Teorema de Bayes , Microscopia de Fluorescência por Excitação Multifotônica/estatística & dados numéricos , Modelos Neurológicos , Animais , Sinalização do Cálcio , Biologia Computacional , Ácido Glutâmico/fisiologia , Heurística , Técnicas In Vitro , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Transgênicos , Modelos Estatísticos , Neurônios/fisiologia , Distribuição Normal , Estimulação Luminosa , Análise de Regressão , Retina/fisiologia , Retina/efeitos da radiação , Razão Sinal-Ruído , Incerteza
13.
Nat Commun ; 10(1): 3695, 2019 08 16.
Artigo em Inglês | MEDLINE | ID: mdl-31420541

RESUMO

Sub-diffraction microscopy enables bio-imaging with unprecedented clarity. However, most super-resolution methods require complex, costly purpose-built systems, involve image post-processing and struggle with sub-diffraction imaging in 3D. Here, we realize a conceptually different super-resolution approach which circumvents these limitations and enables 3D sub-diffraction imaging on conventional confocal microscopes. We refer to it as super-linear excitation-emission (SEE) microscopy, as it relies on markers with super-linear dependence of the emission on the excitation power. Super-linear markers proposed here are upconversion nanoparticles of NaYF4, doped with 20% Yb and unconventionally high 8% Tm, which are conveniently excited in the near-infrared biological window. We develop a computational framework calculating the 3D resolution for any viable scanning beam shape and excitation-emission probe profile. Imaging of colominic acid-coated upconversion nanoparticles endocytosed by neuronal cells, at resolutions twice better than the diffraction limit both in lateral and axial directions, illustrates the applicability of SEE microscopy for sub-cellular biology.


Assuntos
Imagem Tridimensional/métodos , Microscopia Confocal/métodos , Microscopia de Fluorescência por Excitação Multifotônica/métodos , Nanopartículas/ultraestrutura , Neurônios/ultraestrutura , Animais , Endocitose , Células PC12 , Ratos
14.
Methods Mol Biol ; 2018: 151-175, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31228156

RESUMO

The rat is a favored model organism to study physiological function in vivo. This is largely due to the fact that it has been used for decades and is often more comparable to corresponding human conditions (both normal and pathologic) than mice. Although the development of genetic manipulations in rats has been slower than in mice, recent advances of new genomic editing tools allow for the generation of targeted global and specific cell type mutations in different rat strains. The rat is an ideal model for advancing imaging techniques like intravital multi-photon microscopy or IVMPM. Multi-photon excitation microscopy can be applied to visualize real-time physiologic events in multiple organs including the kidney. This imaging modality can generate four-dimensional high resolution images that are inherently confocal due to the fact that the photon density needed to excite fluorescence only occurs at the objective focal plane, not above or below. Additionally, longer excitation wavelengths allow for deeper penetration into tissue, improved excitation, and are inherently less phototoxic than shorter excitation wavelengths. Applying imaging tools to study physiology in rats has become a valuable scientific technique due to the relatively simple surgical procedures, improved quality of reagents, and reproducibility of established assays. In this chapter, the authors provide an example of the application of fluorescent techniques to study cardio-renal functions in rat models. Use of experimental procedures described here, together with multiple available genetically modified animal models, provide new prospective for the further application of multi-photon microscopy in basic and translational research.


Assuntos
Coração/anatomia & histologia , Microscopia Intravital/veterinária , Rim/anatomia & histologia , Microscopia de Fluorescência por Excitação Multifotônica/veterinária , Animais , Humanos , Imagem Tridimensional , Microscopia de Fluorescência , Modelos Animais , Ratos
15.
Nat Commun ; 10(1): 2533, 2019 06 10.
Artigo em Inglês | MEDLINE | ID: mdl-31182715

RESUMO

Spatiotemporally synchronised neuronal activity is central to sensation, motion and cognition. Brain circuits consist of dynamically interconnected neuronal cell-types, thus elucidating how neuron types synergise within the network is key to understand the neuronal orchestra. Here we show that in neocortex neuron-network coupling is neuronal cell-subtype specific. Employing in vivo two-photon (2-p) Calcium (Ca) imaging and 2-p targeted whole-cell recordings, we cell-type specifically investigated the coupling profiles of genetically defined neuron populations in superficial layers (L) of mouse primary visual cortex (V1). Our data reveal novel subtlety of neuron-network coupling in inhibitory interneurons (INs). Parvalbumin (PV)- and Vasoactive intestinal peptide (VIP)-expressing INs exhibit skewed distributions towards strong network-coupling; in Somatostatin (SST)-expressing INs, however, two physiological subpopulations are identified with distinct neuron-network coupling profiles, providing direct evidence for subtype specificity. Our results thus add novel functional granularity to neuronal cell-typing, and provided insights critical to simplifying/understanding neural dynamics.


Assuntos
Interneurônios/fisiologia , Neurônios/fisiologia , Córtex Visual/citologia , Córtex Visual/fisiologia , Animais , Cálcio/metabolismo , Eletrofisiologia , Potenciais Evocados Visuais , Feminino , Masculino , Camundongos Transgênicos , Microscopia de Fluorescência por Excitação Multifotônica , Parvalbuminas/metabolismo , Estimulação Luminosa , Somatostatina/metabolismo , Peptídeo Intestinal Vasoativo/metabolismo
16.
Chemistry ; 25(46): 10954-10964, 2019 Aug 14.
Artigo em Inglês | MEDLINE | ID: mdl-31215691

RESUMO

Epicocconone 1 is a natural chromophore isolated from the fungus Epicoccum nigrum that has shown applications in proteomics and fluorescent microscopy thanks to its unique pro-fluorescence properties. The modification of the skeleton of the natural product by replacing the triene side chain by a fluorenyl scaffold can noticeably increase the fluorophore's absorption coefficient. The synthesis of the analogues of the natural product has been made possible by the use of a palladium-catalyzed carbonylation reaction, allowing the construction of the ß-keto-dioxinone key intermediate. Two-photon absorption cross-section measurements of the fluorenyl epicocconone analogues show a structure dependency with values ranging from 60 to 280 GM and live cell imaging show intense staining of intracellular vesicle-like structures around the nucleus.


Assuntos
Benzopiranos/química , Fluorenos/química , Corantes Fluorescentes/química , Furanos/química , Cetonas/química , Microscopia de Fluorescência por Excitação Multifotônica/métodos , Animais , Benzopiranos/síntese química , Catálise , Fluorenos/síntese química , Corantes Fluorescentes/síntese química , Furanos/síntese química , Cetonas/síntese química , Imagem Óptica/métodos , Células PC12 , Paládio/química , Ratos
17.
Biochemistry (Mosc) ; 84(Suppl 1): S69-S88, 2019 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31213196

RESUMO

Multiphoton microscopy (MPM) is a method of molecular imaging and specifically of intravital imaging that is characterized by high spatial resolution in combination with a greater depth of penetration into the tissue. MPM is a multimodal method based on detection of nonlinear optical signals - multiphoton fluorescence and optical harmonics - and also allows imaging with the use of the parameters of fluorescence decay kinetics. This review describes and discusses photophysical processes within major reporter molecules used in MPM with endogenous contrasts and summarizes several modern experiments that illustrate the capabilities of label-free MPM for molecular imaging of biochemical processes in connective tissue and cells.


Assuntos
Fenômenos Bioquímicos , Células/metabolismo , Tecido Conjuntivo/metabolismo , Corantes Fluorescentes/química , Microscopia de Fluorescência por Excitação Multifotônica/métodos , Imagem Óptica/métodos , Humanos
18.
Biochemistry (Mosc) ; 84(Suppl 1): S108-S123, 2019 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31213198

RESUMO

Pathogenesis of many diseases is associated with changes in the collagen spatial structure. Traditionally, the 3D structure of collagen in biological tissues is analyzed using histochemistry, immunohistochemistry, magnetic resonance imaging, and X-radiography. At present, multiphoton microscopy (MPM) is commonly used to study the structure of biological tissues. MPM has a high spatial resolution comparable to histological analysis and can be used for direct visualization of collagen spatial structure. Because of a large volume of data accumulated due to the high spatial resolution of MPM, special analytical methods should be used for identification of informative features in the images and quantitative evaluation of relationship between these features and pathological processes resulting in the destruction of collagen structure. Here, we describe current approaches and achievements in the identification of informative features in the MPM images of collagen in biological tissues, as well as the development on this basis of algorithms for computer-aided classification of collagen structures using machine learning as a type of artificial intelligence methods.


Assuntos
Colágeno/ultraestrutura , Aprendizado de Máquina , Microscopia de Fluorescência por Excitação Multifotônica/métodos , Humanos
19.
Biochemistry (Mosc) ; 84(Suppl 1): S144-S158, 2019 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31213200

RESUMO

This short review describes recent progress in using optical clearing (OC) technique in skin studies. Optical clearing is an efficient tool for enhancing the probing depth and data quality in multiphoton microscopy and Raman spectroscopy. Here, we discuss the main mechanisms of OC, its safety, advantages, and limitations. The data on the OC effect on the skin water content are presented. It was demonstrated that 70% glycerol and 100% OmnipaqueTM 300 reduce the water content in the skin. Both OC agents (OCAs) significantly affect the strongly bound and weakly bound water. However, OmnipaqueTM 300 causes considerably less skin dehydration than glycerol. In addition, the results of examination of the OC effect on autofluorescence in two-photon excitation and background fluorescence in Raman scattering at different skin depths are presented. It is shown that OmnipaqueTM 300 is a promising OCA due to its ability to reduce background fluorescence in the upper skin layers. The possibility of multimodal imaging combining optical methods and OC technique is discussed.


Assuntos
Microscopia de Fluorescência por Excitação Multifotônica/métodos , Pele/diagnóstico por imagem , Pele/ultraestrutura , Análise Espectral Raman/métodos , Dermatologia , Glicerol/química , Humanos , Água/metabolismo
20.
Anticancer Res ; 39(6): 2721-2727, 2019 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-31177107

RESUMO

BACKGROUND/AIM: The aim of this study was to investigate radiation-induced tumour vascular damage and its impact thereof on the outcome of stereotactic body radiotherapy (SBRT). MATERIALS AND METHODS: Vessel densities in animal tumours before and after a single dose of 20 Gy were quantified and used as input for simulations of three-dimensional tumours with heterogeneous oxygenation. SBRT treatments of the modelled tumours in 1-8 fractions were simulated. The impact of vessel collapse on the outcome of SBRT was investigated by calculating tumour control probability (TCP) and the dose required to obtain a TCP of 50% (D50). RESULTS: A radiation-induced increase of acute hypoxia in tumours during SBRT treatment could be simulated based on the experimental data. The D50 values for these tumours were higher than for the simulated tumours without vessel collapse. CONCLUSION: The vascular changes after high doses of radiation could compromise the outcome of SBRT by increasing tumour hypoxia.


Assuntos
Vasos Sanguíneos/lesões , Vasos Sanguíneos/efeitos da radiação , Neoplasias da Mama/radioterapia , Radiocirurgia/efeitos adversos , Animais , Vasos Sanguíneos/diagnóstico por imagem , Neoplasias da Mama/irrigação sanguínea , Neoplasias da Mama/diagnóstico por imagem , Hipóxia Celular , Linhagem Celular Tumoral , Fracionamento da Dose de Radiação , Feminino , Humanos , Camundongos , Microscopia de Fluorescência por Excitação Multifotônica , Modelos Biológicos , Transplante de Neoplasias , Resultado do Tratamento
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