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.

• Klíčová slova
• Drug delivery, Fluorescence imaging, Theranostics,
• 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
• Názvy látek
• fluorescenční barviva MeSH
• protinádorové látky 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.

• Klíčová slova
• F-19 magnetic resonance imaging, Nanoparticles, Optical imaging, Pancreatic islets, Transplantation,
• 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
• Názvy látek
• fluor 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.

• Klíčová slova
• AS1411 aptamer, Aptamer, Fluorescence microscopy imaging, Intracellular fluorescence, Phase-modulation lifetime measurement,
• 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
• Názvy látek
• AGRO 100 MeSH Prohlížeč
• aptamery nukleotidové MeSH
• oligodeoxyribonukleotidy MeSH

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.

• Klíčová slova
• FLEX, HyPlant, airborne measurements, chlorophyll fluorescence, imaging spectroscopy, photosynthesis, remote sensing, sun-induced fluorescence, vegetation monitoring,
• MeSH
• chlorofyl fyziologie   MeSH
• fluorescence MeSH
• fluorescenční spektrometrie * MeSH
• fotosyntéza * MeSH
• sluneční záření * MeSH
• technologie dálkového snímání metody   MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Názvy látek
• chlorofyl MeSH

Fluorescent probes that light-up upon reaction with complementary bioorthogonal reagents are superior tools for no-wash fluorogenic bioimaging applications. In this work, a thorough study is presented on a set of seventeen structurally diverse coumarin-tetrazine probes that produce fluorescent dyes with exceptional turn-on ratios when reacted with trans-cyclooctene (TCO) and bicyclononyne (BCN) dienophiles. In general, formation of the fully aromatic pyridazine-containing dyes resulting from the reaction with BCN was found superior in terms of fluorogenicity. However, evaluation of the probes in cellular imaging experiments revealed that other factors, such as reaction kinetics and good cell permeability, prevail over the fluorescence turn-on properties. The best compound identified in this study showed excellent performance in live cell-labeling experiments and enabled no-wash fluorogenic imaging on a timescale of seconds.

• Klíčová slova
• click chemistry, coumarins, fluorescence, live cell bioimaging, tetrazines,
• MeSH
• fluorescenční barviva analýza   MeSH
• heterocyklické sloučeniny analýza   MeSH
• konfokální mikroskopie MeSH
• kumariny analýza   MeSH
• lidé MeSH
• nádorové buněčné linie MeSH
• optické zobrazování * MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• fluorescenční barviva MeSH
• heterocyklické sloučeniny MeSH
• kumariny MeSH

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
• Názvy látek
• chlorofyl MeSH

Imaging methods based on light detection are being increasingly used for the non-invasive assessment of tumour growth in animal models. In contrast with bioluminescence imaging, there are no studies assessing the use of macroscopic fluorescence imaging for the longitudinal monitoring of tumour growth in an orthotopic glioma mouse model. Glioma cells expressing the red-shifted fluorescent protein mKate2 were orthotopically implanted to NOD-rag mice and the tumour size estimated by macroscopic fluorescence imaging was compared to the tumour volume determined morphometrically. There was no significant correlation between the data obtained by non-invasive macroscopic fluorescence imaging and post mortem morphometry. In addition, the fluorescence imaging failed to detect a morphometrically verified difference in tumour volume between animals with tumours expressing a potential tumour suppressor gene and controls. The fluorescence signal was affected by the spatial pattern of tumour growth and substantially attenuated by the interfering brain tissue. Our results indicate that the fluorescence signal emitted by glioma cells reflected not only the tumour mass, but also its spatial distribution. Macroscopic planar FLI in an epi-illumination mode and a conventional source of excitation light therefore appears to be more suitable for semi-quantitative assessment of the tumour growth especially in the case of superficially located tumours rather than for precise volume estimation of the xenografts located deep within the brain tissue.

• MeSH
• diagnostické zobrazování metody   MeSH
• fluorescence * MeSH
• gliom diagnóza   MeSH
• lidé MeSH
• modely nemocí na zvířatech MeSH
• myši MeSH
• nádorové buněčné linie MeSH
• optické zobrazování metody   MeSH
• transplantace nádorů MeSH
• zvířata MeSH
• Check Tag
• lidé MeSH
• mužské pohlaví MeSH
• myši MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH

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
• Názvy látek
• aluminum tetrasulfophthalocyanine MeSH Prohlížeč
• fotosenzibilizující látky MeSH
• indoly MeSH
• organokovové sloučeniny MeSH
• singletový kyslík MeSH

Polymeric nanofiber materials loaded with photosensitizers exhibit significant antibacterial activity due to their generation of cytotoxic singlet oxygen O(2)((1)Δ(g)). A time-gated fluorescence imaging technique was used to monitor the photosensitized processes in polystyrene (PS) and gelatin (GE) nanofibers loaded with 0.1 wt % tetraphenylporphyrin (TPP) photosensitizer. The fluorescence decay of TPP at the periphery of the PS nanofibers was single exponential. Increased fluorescence quenching was observed in the domains with higher TPP loading, located in the center of the nanofibers, and added a shorter lifetime component to the kinetics. The domains exhibiting singlet oxygen activity within the nanofibers were visualized and analyzed by singlet oxygen-sensitized delayed fluorescence imaging (SODF). Whereas O(2)((1)Δ(g)) was produced in PS nanofibers, its production in GE nanofibers was limited. These results were confirmed by time-resolved phosphorescence measurements at 1270 nm.

• MeSH
• časové faktory MeSH
• fluorescence * MeSH
• fluorescenční mikroskopie MeSH
• nanovlákna chemie   MeSH
• polymery chemie   MeSH
• povrchové vlastnosti MeSH
• singletový kyslík chemie   MeSH
• velikost částic MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Názvy látek
• polymery MeSH
• singletový kyslík 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).

• MeSH
• doxorubicin analogy a deriváty   farmakokinetika   MeSH
• lidé MeSH
• nádorové buněčné linie MeSH
• nanočástice MeSH
• nosiče léků * MeSH
• optické zobrazování metody   MeSH
• polymery MeSH
• protinádorové látky farmakokinetika   MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• doxorubicin MeSH
• nosiče léků * MeSH
• pirarubicin MeSH Prohlížeč
• polymery MeSH
• protinádorové látky MeSH