1. Fluorescent covalent organic frameworks : promising bioimaging materialsChimatahalli Santhakumar Karthik, Tina Škorjanc, Dinesh Shetty, 2024, original scientific article Abstract: Fluorescent covalent organic frameworks (COFs) have emerged as promising candidates for imaging living cells due to their unique properties and adjustable fluorescence. In this mini-review, we provide an overview of recent advancements in fluorescent COFs for bioimaging applications. We discuss the strategies used to design COFs with desirable properties such as high photostability, excellent biocompatibility, and pH sensitivity. Additionally, we explore the various ways in which fluorescent COFs are utilized in bioimaging, including cellular imaging, targeting specific organelles, and tracking biomolecules. We delve into their applications in sensing intracellular pH, reactive oxygen species (ROS), and specific biomarkers. Furthermore, we examine how functionalization techniques enhance the targeting and imaging capabilities of fluorescent COFs. Finally, we discuss the challenges and prospects in the field of fluorescent COFs for bioimaging in living cells, urging further research in this exciting area. Keywords: covalent organic frameworks, fluorescent materials, imaging, bioimaging, biosensors Published in RUNG: 05.03.2024; Views: 463; Downloads: 3 Full text (5,40 MB) This document has many files! More... |
2. In vitro tumor hypoxia imaging with fluorescent covalent organic frameworksTina Skorjanc, Dinesh Shetty, Damjan Makuc, Gregor Mali, Martina Bergant Marušič, Matjaž Valant, 2023, published scientific conference contribution abstract Abstract: Hypoxia refers to a condition where cells and tissues experience low, inadequate levels of O2. While healthy tissues are typically supplied with sufficient O2 (normoxia), cancerous tissues commonly face hypoxia due to the tumor’s extraordinarily high demand for oxygen. Various fluorescent small-molecule probes have been designed for selective detection of hypoxia in living cells, but few nanomaterials have been investigated for this type of bioimaging. Herein, we prepare a fluorescent covalent organic framework (COF) with β-ketoenamine linkages and post-synthetically modify it to conjugate hypoxia-sensitive nitroimidazole moieties
into its pores (NI-COF). Stacks of sheets in NI-COF observed under electron microscopy were exfoliated by ultrasonication, and dynamic light scattering measurements confirmed particle size of less than 200 nm. Thus-prepared material exhibited good stability in physiological conditions and low cytotoxicity in in vitro experiments. NI-COF also showed useful fluorescence properties with an emission peak at 490 nm (λex = 420 nm) at both neutral and mildly acidic pH levels that are characteristic of tumor tissues. Encouraged by the favorable properties of the material, we incubated HeLa cells pre-treated in either hypoxic or normoxic conditions with NI-COF. Fluorescence microscopy images demonstrated that the material was preferentially taken up by hypoxic cells, which showed higher fluorescence signal in their interior than cells cultured under normoxia conditions. It is anticipated that this study will stimulate further developments of COFs for imaging various biological conditions. Keywords: hypoxia, fluorescence, covalent organic frameworks, imaging, tumor cells Published in RUNG: 19.09.2023; Views: 905; Downloads: 3 Link to file This document has many files! More... |
3. Covalent organic frameworks for fluorescent imaging of hypoxiaTina Škorjanc, Dinesh Shetty, Gregor Mali, Damjan Makuc, Martina Bergant Marušič, Matjaž Valant, 2023, published scientific conference contribution abstract Keywords: hypoxia, covalent organic frameworks, imaging, fluorescence, post-synthetic modification Published in RUNG: 06.06.2023; Views: 1149; Downloads: 2 Link to file This document has many files! More... |
4. Nitroreductase-sensitive fluorescent covalent organic framework for tumor hypoxia imaging in cellsTina Škorjanc, Dinesh Shetty, Sushil Kumar, Damjan Makuc, Gregor Mali, Janez Volavšek, Martina Bergant Marušič, Matjaž Valant, 2023, original scientific article Keywords: covalent organic frameworks, imaging, hypoxia, fluorescence, cancer cells Published in RUNG: 17.05.2023; Views: 1171; Downloads: 10 Full text (1,55 MB) This document has many files! More... |
5. Research progress and applications of multivalent, multispecific and modified nanobodies for disease treatmentJiewen Wang, Guangbo Kang, Haibin Yuan, Xiaocang Cao, He Huang, Ario De Marco, 2022, original scientific article Keywords: nanobody multimers, immunomodulation, intrabodies, imaging, nanobody functionalization Published in RUNG: 18.01.2022; Views: 1816; Downloads: 155 Link to full text This document has many files! More... |
6. Orographic gravity waves in OH-airglow imaging systemsSabine Wuest, Jonas Till, René Sedlak, Patrick Hannawald, Carsten Schmidt, Samo Stanič, Michael Bittner, 2020, published scientific conference contribution abstract Abstract: Atmospheric dynamics is strongly influenced by waves on different scales. Airflow over mountains can lead to all kinds of atmospheric waves, planetary and gravity waves as well as infrasound. Under certain circumstances these waves can propagate through the atmosphere and lead to a re- distribution of energy. In the case of gravity waves, a stably stratified atmosphere is a mandatory requirement for their generation and vertical propagation. Additionally, the vertical propagation depends on the horizontal wind field. In the Alpine and pre-Alpine region, we currently operate five OH-airglow imaging systems, which allow the investigation of orographic gravity waves. Depending on tropo-, strato- and mesospheric wind and temperature, it is checked which wavelengths can propagate into the fields of view of our instruments. This is done for a whole year in order to take into account annual and semi- annual cycles in wind and temperature. Concerning the generation of gravity waves, we put our focus on our OH-airglow imager (FAIM) deployed at Otlica (45.9°N, 13.9°E), Slovenia. Here, we also have additional measurements of an OH-airglow spectrometer (GRIPS). In case studies, we investigate whether strong wind events (Bora) lead to strong gravity waves activity or enhanced potential energy density. Keywords: Orographic gravity waves, Bora, Otlica, Slovenia, OH-airglow imaging Published in RUNG: 08.10.2020; Views: 2542; Downloads: 0 This document has many files! More... |
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9. Localization, ligand environment, bioavailability and toxicity of mercury in Boletus spp. and Scutiger pes-caprae mushroomsAnja Kavčič, Klemen Mikuš, Marta Debeljak, Johannes Teun van Elteren, Iztok Arčon, Alojz Kodre, Peter Kump, Andreas-Germanos Karydas, Alessandro Migliori, Mateusz Czyzycki, Katarina Vogel-Mikuš, 2019, original scientific article Abstract: This study provides information on mercury (Hg) localization, speciation and ligand environment in edible mushrooms: Boletus edulis, B. aereus and Scutiger pes-caprae collected at non-polluted and Hg polluted sites, by LA-ICP-MS, SR-μ-XRF and Hg L3-edge XANES and EXAFS. Mushrooms (especially young ones) collected at Hg polluted sites can contain more than 100 μg Hg g−1 of dry mass. Imaging of the element distribution shows that Hg accumulates mainly in the spore-forming part (hymenium) of the cap. Removal of hymenium before consumption can eliminate more than 50% of accumulated Hg.
Mercury is mainly coordinated to di-thiols (43–82%), followed by di-selenols (13–35%) and tetra-thiols (12–20%). Mercury bioavailability, as determined by feeding the mushrooms to Spanish slugs (known metal bioindicators owing to accumulation of metals in their digestive gland), ranged from 4% (S. pes-caprae) to 30% (B. aereus), and decreased with increasing selenium (Se) levels in the mushrooms. Elevated Hg levels in mushrooms fed to the slugs induced toxic effects, but these effects were counteracted with increasing Se concentrations in the mushrooms, pointing to a protective role of Se against Hg toxicity through HgSe complexation. Nevertheless, consumption of the studied mushroom species from Hg polluted sites should be avoided. Keywords: edible mushrooms, HgSe complex, imaging of elemental distribution, LA-ICP-MS, alpha-XRF, XAS Published in RUNG: 24.10.2019; Views: 4643; Downloads: 0 This document has many files! More... |
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