fluorescence imaging Dotaz Zobrazit nápovědu
In the past several decades, nanosized drug delivery systems with various targeting functions and controlled drug release capabilities inside targeted tissues or cells have been intensively studied. Understanding their pharmacokinetic properties is crucial for the successful transition of this research into clinical practice. Among others, fluorescence imaging has become one of the most commonly used imaging tools in pre-clinical research. The development of increasing numbers of suitable fluorescent dyes excitable in the visible to near-infrared wavelengths of the spectrum has significantly expanded the applicability of fluorescence imaging. This paper focuses on the potential applications and limitations of non-invasive imaging techniques in the field of drug delivery, especially in anticancer therapy. Fluorescent imaging at both the cellular and systemic levels is discussed in detail. Additionally, we explore the possibility for simultaneous treatment and imaging using theranostics and combinations of different imaging techniques, e.g., fluorescence imaging with computed tomography.
- MeSH
- celotělové zobrazování metody MeSH
- fluorescence MeSH
- fluorescenční barviva chemie MeSH
- lékové transportní systémy metody MeSH
- lidé MeSH
- nádory diagnóza farmakoterapie MeSH
- optické zobrazování metody MeSH
- protinádorové látky aplikace a dávkování farmakokinetika MeSH
- teranostická nanomedicína metody MeSH
- zvířata MeSH
- Check Tag
- lidé MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- přehledy MeSH
Cancer is a serious disease that causes 25% of deaths in the developed countries. Significant impact on the cancer patients survival has early detection of this disease, therefore great attention is paid to its imaging. Fluorescence imaging represents powerful imaging method for the cell detection. For the successful detection of tumour cells, the specific targeting of fluorescence probes to the tumour tissue has a key role. Interesting materials enabling the imaging of tumour cells are fluorescence nanoparticles. For the accurate imaging, the NPs should be conjugated with targeting ligands and/or constructed as off-on probes.
Multi-color fluorescence emission from leaf tissues is presented as a powerful reporter on plant biochemistry and physiology that can be applied both at macro- and micro-scales. The blue-green fluorescence emission is typically excited by ultraviolet (UV) excitation. However, this approach cannot be applied in investigating intact leaf interior because the UV photons are largely absorbed in the epidermis of the leaf surface. This methodological barrier is eliminated by replacing the UV photon excitation by excitation with two infra-red photons of the same total energy. We demonstrate this approach by using two-photon excitation for microscopy of Arabidopsis thaliana leaves infected by pathogenic bacterium Pseudomonas syringae. The leaf structures are visualized by red chlorophyll fluorescence emission reconstructed in 3-D images while the bacteria are detected by the green emission of engineered fluorescence protein.
- MeSH
- Arabidopsis metabolismus mikrobiologie MeSH
- chlorofyl metabolismus MeSH
- fluorescenční spektrometrie MeSH
- listy rostlin metabolismus mikrobiologie MeSH
- mezofylové buňky cytologie metabolismus MeSH
- nemoci rostlin mikrobiologie MeSH
- Pseudomonas syringae fyziologie MeSH
- tabák metabolismus mikrobiologie MeSH
- zobrazování trojrozměrné metody MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
PURPOSE: Combining specific and quantitative F-19 magnetic resonance imaging (MRI) with sensitive and convenient optical imaging provides complementary information about the distribution and viability of transplanted pancreatic islet grafts. In this study, pancreatic islets (PIs) were labeled with positively charged multimodal nanoparticles based on poly(lactic-co-glycolic acid) (PLGA-NPs) with encapsulated perfluoro-15-crown-5-ether and the near-infrared fluorescent dye indocyanine green. PROCEDURES: One thousand and three thousand bioluminescent PIs were transplanted into subcutaneous artificial scaffolds, which served as an alternative transplant site. The grafts were monitored using in vivo F-19 MR, fluorescence, and bioluminescence imaging in healthy rats for 2 weeks. RESULTS: Transplanted PIs were unambiguously localized in the scaffolds by F-19 MRI throughout the whole experiment. Fluorescence was detected in the first 4 days after transplantation only. Importantly, in vivo bioluminescence correlated with the F-19 MRI signal. CONCLUSIONS: We developed a trimodal imaging platform for in vivo examination of transplanted PIs. Fluorescence imaging revealed instability of the fluorescent dye and its limited applicability for longitudinal in vivo studies. A correlation between the bioluminescence signal and the F-19 MRI signal indicated the fast clearance of PLGA-NPs from the transplantation site after cell death, which addresses a major issue with intracellular imaging labels. Therefore, the proposed PLGA-NP platform is reliable for reflecting the status of transplanted PIs in vivo.
- MeSH
- endocytóza MeSH
- fluor chemie MeSH
- fluorescence MeSH
- Langerhansovy ostrůvky diagnostické zobrazování MeSH
- luminiscenční měření * MeSH
- magnetická rezonanční tomografie * MeSH
- modely u zvířat MeSH
- molekulární zobrazování * MeSH
- potkani inbrední LEW MeSH
- potkani transgenní MeSH
- přežití tkáně MeSH
- tkáňové podpůrné struktury chemie MeSH
- transplantace Langerhansových ostrůvků * MeSH
- zvířata MeSH
- Check Tag
- mužské pohlaví MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
Quantum dots are small semiconductor nanoparticles with great fluorescence properties including broad excitation and narrow emission spectra, high quantum yields, high photostability, possibility to be synthesize in a wide variety of colors and suitability for functionalization they are new member of a family of fluorescent labels. Due to their unique optical and electrochemical properties they have proven to be very beneficial not only for biomolecule labeling for in vitro analysis but also for in vivo applications. This review article is focused on the current imaging methods. The usage of fluorescence methods in diagnosis is discussed. This paper concerns to the fluorescence imaging and possibilities of the usage of quantum dots in in vivo imaging.
Singlet oxygen is a highly reactive species which is involved in a number of processes, including photodynamic therapy of cancer. Its very weak near-infrared emission makes imaging of singlet oxygen in biological systems a long-term challenge. We address this challenge by introducing Singlet Oxygen Feedback Delayed Fluorescence (SOFDF) as a novel modality for semi-direct microscopic time-resolved wide-field imaging of singlet oxygen in biological systems. SOFDF has been investigated in individual fibroblast cells incubated with a well-known photosensitizer aluminium phthalocyanine tetrasulfonate. The SOFDF emission from the cells is several orders of magnitude stronger and much more readily detectable than the very weak near-infrared phosphorescence of singlet oxygen. Moreover, the analysis of SOFDF kinetics enables us to estimate the lifetimes of the involved excited states. Real-time SOFDF images with micrometer spatial resolution and submicrosecond temporal-resolution have been recorded. Interestingly, a steep decrease in the SOFDF intensity after the photodynamically induced release of a photosensitizer from lysosomes has been demonstrated. This effect could be potentially employed as a valuable diagnostic tool for monitoring and dosimetry in photodynamic therapy.
- MeSH
- buňky 3T3 MeSH
- časové faktory MeSH
- fibroblasty chemie cytologie MeSH
- fluorescence * MeSH
- fluorescenční mikroskopie MeSH
- fotochemoterapie MeSH
- fotosenzibilizující látky chemie MeSH
- indoly chemie MeSH
- kultivované buňky MeSH
- myši MeSH
- optické zobrazování * MeSH
- organokovové sloučeniny chemie MeSH
- singletový kyslík analýza chemie MeSH
- viabilita buněk MeSH
- zvířata MeSH
- Check Tag
- myši MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
I přes pokrok v terapii nádorů hlavy a krku se celkové pětileté přežití za posledních několik dekád prakticky nezměnilo, a to zejména kvůli pozdní diagnóze. Vzhledem k tomu, že v minulosti byly slizniční nádory v ORL oblasti zachycovány až ve vyšších stadiích nemoci, byly vyvinuty nové endoskopické optické zobrazovací metody pro lepší a dřívější detekci těchto lézí. Dělíme je na dvě základní skupiny. Horizontální metody zobrazují povrch sliznice (úzkopásmové zobrazení – narrow band imaging, autofluorescence, fotodynamická diagnostika, zvětšovací a kontaktní endoskopie). Vertikální metody umožňují zobrazit různé vrstvy sliznice (optická koherentní tomografie a konfokální laserová endomikroskopie). V zahraničí jsou běžně v současné klinické praxi v různých oborech využívány narrow band imaging a autofluorescence. Do ORL působnosti se stále častěji začleňuje i zvětšovací a kontaktní endoskopie. Autoři předkládají souhrnný přehled o využití narrow band imaging a autofluorescenci při diagnostice karcinomu orofaryngu.
Despite progress in the treatment of head and neck cancer, the five-year overall survival rate is still low because of late dia gnosis. The head and neck mucosal tumours were usually diagnosed in higher stages in past, therefore new endoscopic optical imaging methods were developed for better and earlier detection of these lesions. They are divided in two main groups – horizontal and vertical methods. The horizontal ones show the surface of the mucous membrane (narrow band imaging, autofluorescence, photodynamic diagnosis, magnifying and contact endoscopy). The vertical ones show different layers of the mucosa (optical coherence tomography and confocal endomicroscopy). Narrow band imaging and autofluorescence endoscopy are already used routinely in foreign countries, magnifying and contact endoscopy are getting to practice recently. The authors present a summary of narrow band imaging and autofluorescence endoscopy usage in the diagnostics of oropharyngeal carcinoma.
- MeSH
- diagnostické zobrazování metody MeSH
- endoskopie metody MeSH
- lidé MeSH
- nádory orofaryngu * diagnostické zobrazování diagnóza MeSH
- optické zobrazování metody MeSH
- úzkopásmové zobrazení metody MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- přehledy MeSH
Time-resolved microspectrofluorimetry and fluorescence microscopy imaging-two complementary fluorescence techniques-provide important information about the intracellular distribution, level of uptake and binding/interactions inside living cell of the labeled molecule of interest. They were employed to monitor the "fate" of AS1411 aptamer labeled by ATTO 425 in human living cells. Confocal microspectrofluorimeter adapted for time-resolved intracellular fluorescence measurements by using a phase-modulation principle with homodyne data acquisition was employed to obtain emission spectra and to determine fluorescence lifetimes in U-87 MG tumor brain cells and Hs68 non-tumor foreskin cells. Acquired spectra from both the intracellular space and the reference solutions were treated to observe the aptamer localization and its interaction with biological structures inside the living cell. The emission spectra and the maximum emission wavelengths coming from the cells are practically identical, however significant lifetime lengthening was observed for tumor cell line in comparison to non-tumor one.
- MeSH
- aptamery nukleotidové metabolismus MeSH
- časové faktory MeSH
- fluorescenční mikroskopie metody MeSH
- fluorescenční spektrometrie metody MeSH
- intracelulární prostor genetika metabolismus MeSH
- lidé MeSH
- nádorové buněčné linie MeSH
- oligodeoxyribonukleotidy genetika metabolismus MeSH
- sekvence nukleotidů MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
Nanocarriers bearing anticancer drugs are promising candidates to improve the efficacy of cancer therapy and minimize side effects. The most potent cytostatics used in the treatment of various cancers are anthracyclines, e.g. doxorubicin or pirarubicin. Recently, polymer therapeutics carrying anthracyclines have been intensively studied. The precise characterization of in vitro nanocarrier biological behavior brings a better understanding of the nanocarrier characteristics and enables prediction of the behavior of the nanocarrier during in vivo application. Advanced fluorescence detection methods, e.g. fluorescence lifetime imaging microscopy (FLIM), were successfully exploited to describe the properties of various polymeric nano-systems and contributed to a complex view of anthracyclines' intracellular transport and DNA intercalation. Here, we report the application of a specific technique for processing FLIM images, called fluorescence pattern decomposition, to evaluate early events after doxorubicin or pirarubicin treatment of cells. Moreover, we characterized changes in the intracellular localization and release of the anthracyclines during the incubation of cells with polymer nanotherapeutics based on poly[N-(2-hydroxypropyl)-methacrylamide] (pHPMA).
Variations in photosynthesis still cause substantial uncertainties in predicting photosynthetic CO2 uptake rates and monitoring plant stress. Changes in actual photosynthesis that are not related to greenness of vegetation are difficult to measure by reflectance based optical remote sensing techniques. Several activities are underway to evaluate the sun-induced fluorescence signal on the ground and on a coarse spatial scale using space-borne imaging spectrometers. Intermediate-scale observations using airborne-based imaging spectroscopy, which are critical to bridge the existing gap between small-scale field studies and global observations, are still insufficient. Here we present the first validated maps of sun-induced fluorescence in that critical, intermediate spatial resolution, employing the novel airborne imaging spectrometer HyPlant. HyPlant has an unprecedented spectral resolution, which allows for the first time quantifying sun-induced fluorescence fluxes in physical units according to the Fraunhofer Line Depth Principle that exploits solar and atmospheric absorption bands. Maps of sun-induced fluorescence show a large spatial variability between different vegetation types, which complement classical remote sensing approaches. Different crop types largely differ in emitting fluorescence that additionally changes within the seasonal cycle and thus may be related to the seasonal activation and deactivation of the photosynthetic machinery. We argue that sun-induced fluorescence emission is related to two processes: (i) the total absorbed radiation by photosynthetically active chlorophyll; and (ii) the functional status of actual photosynthesis and vegetation stress.
