Cyanobacteria are prokaryotic organisms characterised by their complex structures and a wide range of pigments. With their ability to fix CO2, cyanobacteria are interesting for white biotechnology as cell factories to produce various high-value metabolites such as polyhydroxyalkanoates, pigments, or proteins. White biotechnology is the industrial production and processing of chemicals, materials, and energy using microorganisms. It is known that exposing cyanobacteria to low levels of stressors can induce the production of secondary metabolites. Understanding of this phenomenon, known as hormesis, can involve the strategic application of controlled stressors to enhance the production of specific metabolites. Consequently, precise measurement of cyanobacterial viability becomes crucial for process control. However, there is no established reliable and quick viability assay protocol for cyanobacteria since the task is challenging due to strong interferences of autofluorescence signals of intercellular pigments and fluorescent viability probes when flow cytometry is used. We performed the screening of selected fluorescent viability probes used frequently in bacteria viability assays. The results of our investigation demonstrated the efficacy and reliability of three widely utilised types of viability probes for the assessment of the viability of Synechocystis strains. The developed technique can be possibly utilised for the evaluation of the importance of polyhydroxyalkanoates for cyanobacterial cultures with respect to selected stressor-repeated freezing and thawing. The results indicated that the presence of polyhydroxyalkanoate granules in cyanobacterial cells could hypothetically contribute to the survival of repeated freezing and thawing.
- MeSH
- fluorescence MeSH
- fluorescenční barviva * metabolismus chemie MeSH
- fyziologický stres * MeSH
- mikrobiální viabilita * MeSH
- polyhydroxyalkanoáty metabolismus MeSH
- průtoková cytometrie * MeSH
- sinice metabolismus fyziologie MeSH
- Synechocystis * metabolismus MeSH
- Publikační typ
- časopisecké články MeSH
Botulinum neurotoxins (BoNTs) and tetanus toxin (TeTX) are the deadliest biological substances that cause botulism and tetanus, respectively. Their astonishing potency and capacity to enter neurons and interfere with neurotransmitter release at presynaptic terminals have attracted much interest in experimental neurobiology and clinical research. Fused with reporter proteins or labelled with fluorophores, BoNTs and TeTX and their non-toxic fragments also offer remarkable opportunities to visualize cellular processes and functions in neurons and synaptic connections. This study presents the state-of-the-art optical probes derived from BoNTs and TeTX and discusses their applications in molecular and synaptic biology and neurodevelopmental research. It reviews the principles of the design and production of probes, revisits their applications with advantages and limitations and considers prospects for future improvements. The versatile characteristics of discussed probes and reporters make them an integral part of the expanding toolkit for molecular neuroimaging, promoting the discovery process in neurobiology and translational neurosciences.
- MeSH
- botulotoxiny chemie MeSH
- fluorescenční barviva chemie MeSH
- lidé MeSH
- molekulární sondy chemie MeSH
- neurony * metabolismus MeSH
- neurotoxiny * MeSH
- neurozobrazování * metody MeSH
- synapse * metabolismus MeSH
- tetanový toxin * chemie MeSH
- zvířata MeSH
- Check Tag
- lidé MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- přehledy MeSH
Chemické transformace kompatibilní s biologickými systémy slouží jako neocenitelné nástroje pro zkoumání biomolekul, sloučenin léčiv a biologických procesů v jejich přirozeném prostředí. Složité prostředí živých organismů vyžaduje, aby tyto reakce byly vysoce selektivní a účinné, což představuje pro oblast organické chemie obrovskou výzvu. V poslední době se objevila řada chemických reakcí, které tyto podmínky splňují, a poskytují proto výzkumným pracovníkům rozmanitou sadu nástrojů. Tento rukopis představuje komplexní přehled současných bioortogonálních reakcí s důrazem na jejich aplikace v zobrazování, diagnostice a medicíně.
Chemical transformations compatible with biological systems serve as invaluable tools for probing biomolecules, drug compounds, and biological processes in their native environments. The complex environment of living organisms requires these reactions to be highly selective and efficient, posing a formidable challenge to the field of organic chemistry. A number of chemical reactions have recently emerged to meet this challenge, providing a diverse toolkit for researchers. This manuscript presents a comprehensive survey of current bioorthogonal reactions, emphasizing their applications in bioimaging, diagnostics, and medicine.
Identifikace buněčných cílů aktivních látek má zásadní význam pro optimalizaci léčiv a minimalizaci jejich nežádoucích vedlejších účinků. Komplexní povaha biologických systémů ztěžuje tuto identifikaci, ale mikroskopické metody, zejména fenotypové testování, reprezentované metodou „Cell Painting“, představují cenný nástroj pro pochopení vlivu látek na úrovni buněk a organel. Tyto metody umožňují rychlé testování rozsáhlých knihoven látek a nabízejí unikátní pohled na mechanismus jejich účinku pozorováním chování buněk, pomocí hodnocení jejich morfologie, pohyblivosti, dělení a migrace. Mikroskopie živých buněk čelí výzvám, jako je fototoxicita, což vyžaduje pečlivý výběr fluorescenčních značek a optimalizaci podmínek. Mezi syntetickými fluorescenčními sondami pro mikroskopii živých buněk vynikají BODIPY barviva se svou syntetickou univerzálností a fotofyzikálními vlastnostmi, které zajišťují minimální poškození vzorku během biozobrazování.
Target identification of active substances is critical in optimizing drugs and minimizing side effects. The complex nature of biological systems presents challenges; to meet them, however, microscopic methods, particularly phenotypic screening, represented by "Cell Painting" method and fluorescent probes, can be used as valuable tools for understanding the impact of various substances at the cellular and organelle levels. These methods enable rapid testing of large libraries of compounds and offer unique insights into their mechanism of action by observing cell behavior, assessing cell morphology, motility, division, and migration. However, live cell microscopy faces challenges like phototoxicity, requiring a careful selection of fluorescent labels and optimized conditions. Among synthetic probes for live cell microscopy, BODIPY dyes stand out for their synthetic versatility and photophysical properties, providing minimal sample damage during bioimaging.
Herein, an advanced bioconjugation technique to synthesize hybrid polymer-antibody nanoprobes tailored for fluorescent cell barcoding in flow cytometry-based immunophenotyping of leukocytes is applied. A novel approach of attachment combining two fluorescent dyes on the copolymer precursor and its conjugation to antibody is employed to synthesize barcoded nanoprobes of antibody polymer dyes allowing up to six nanoprobes to be resolved in two-dimensional cytometry analysis. The major advantage of these nanoprobes is the construct design in which the selected antibody is labeled with an advanced copolymer bearing two types of fluorophores in different molar ratios. The cells after antibody recognition and binding to the target antigen have a characteristic double fluorescence signal for each nanoprobe providing a unique position on the dot plot, thus allowing antibody-based barcoding of cellular samples in flow cytometry assays. This technique is valuable for cellular assays that require low intersample variability and is demonstrated by the live cell barcoding of clinical samples with B cell abnormalities. In total, the samples from six various donors were successfully barcoded using only two detection channels. This barcoding of clinical samples enables sample preparation and measurement in a single tube.
Photon-upconversion nanoparticles (UCNP) have already been established as labels for affinity assays in analog and digital formats. Here, advanced, or smart, systems based on UCNPs coated with active shells, fluorescent dyes, and metal and semiconductor nanoparticles participating in energy transfer reactions are reviewed. In addition, switching elements can be embedded in such assemblies and provide temporal and spatial control of action, which is important for intracellular imaging and monitoring activities. Demonstration and critical comments on representative approaches demonstrating the progress in the use of such UCNPs in bioanalytical assays, imaging, and monitoring of target molecules in cells are reported, including particular examples in the field of cancer theranostics.
- MeSH
- barvicí látky farmakologie klasifikace terapeutické užití MeSH
- fluorescenční barviva farmakologie terapeutické užití MeSH
- indokyanová zeleň farmakologie terapeutické užití MeSH
- lidé MeSH
- nádory děložního čípku patologie MeSH
- nádory endometria patologie MeSH
- nádory vulvy patologie MeSH
- nádory ženských pohlavních orgánů patologie MeSH
- předoperační vyšetření klasifikace MeSH
- radiofarmaka farmakologie klasifikace terapeutické užití MeSH
- radioisotopová scintigrafie metody MeSH
- sentinelová uzlina * diagnostické zobrazování MeSH
- Check Tag
- lidé MeSH
- ženské pohlaví MeSH
- Publikační typ
- přehledy MeSH
In recent years, multifunctional nanocarriers that provide simultaneous drug delivery and imaging have attracted enormous attention, especially in cancer treatment. In this research, a biocompatible fluorescent multifunctional nanocarrier is designed for the co-delivery of capsaicin (CPS) and nitrogen-doped graphene quantum dots (N-GQDs) using the pH sensitive amphiphilic block copolymer (poly(2-ethyl-2-oxazoline)-b-poly(ε-caprolactone), PEtOx-b-PCL). The effects of the critical formulation parameters (the amount of copolymer, the concentration of poly(vinyl alcohol) (PVA) as a stabilizing agent in the inner aqueous phase, and volume of the inner phase) are evaluated to achieve optimal nanoparticle (NP) properties using Central Composite Design. The optimized NPs demonstrated a desirable size distribution (167.8 ± 1.4 nm) with a negative surface charge (-19.9 ± 0.4) and a suitable loading capacity for CPS (70.80 ± 0.05%). The CPS & N-GQD NPs are found to have remarkable toxicity on human breast adenocarcinoma cell line (MCF-7). The solid fluorescent signal is acquired from cells containing multifunctional NPs, according to the confocal microscope imaging results, confirming the significant cellular uptake. This research illustrates the enormous potential for cellular imaging and enhanced cancer therapy offered by multifunctional nanocarriers that combine drug substances with the novel fluorescent agents.
- MeSH
- dusík * chemie MeSH
- fluorescenční barviva chemie MeSH
- grafit * chemie MeSH
- kapsaicin * chemie farmakologie MeSH
- kvantové tečky * chemie terapeutické užití MeSH
- lidé MeSH
- MFC-7 buňky MeSH
- nanočástice * chemie MeSH
- nosiče léků chemie MeSH
- polymery chemie MeSH
- protinádorové látky * farmakologie chemie MeSH
- teranostická nanomedicína * MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- časopisecké články MeSH
The permeation of small molecules across biological membranes is a crucial process that lies at the heart of life. Permeation is involved not only in the maintenance of homeostasis at the cell level but also in the absorption and biodistribution of pharmacologically active substances throughout the human body. Membranes are formed by phospholipid bilayers that represent an energy barrier for permeating molecules. Crossing this energy barrier is assumed to be a singular event, and permeation has traditionally been described as a first-order kinetic process, proportional only to the concentration gradient of the permeating substance. For a given membrane composition, permeability was believed to be a unique property dependent only on the permeating molecule itself. We provide experimental evidence that this long-held view might not be entirely correct. Liposomes were used in copermeation experiments with a fluorescent probe, where simultaneous permeation of two substances occurred over a single phospholipid bilayer. Using an assay of six commonly prescribed drugs, we have found that the presence of a copermeant can either enhance or suppress the permeation rate of the probe molecule, often more than 2-fold in each direction. This can have significant consequences for the pharmacokinetics and bioavailability of commonly prescribed drugs when used in combination and provide new insight into so-far unexplained drug-drug interactions as well as changing the perspective on how new drug candidates are evaluated and tested.
- MeSH
- buněčná membrána metabolismus MeSH
- fluorescenční barviva farmakokinetika chemie MeSH
- fosfolipidy chemie MeSH
- léky na předpis farmakokinetika chemie MeSH
- lidé MeSH
- lipidové dvojvrstvy metabolismus MeSH
- liposomy * chemie MeSH
- permeabilita MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- časopisecké články MeSH
OBJECTIVE: The highly infiltrative growth of glioblastoma (GBM) makes distinction between the tumor and normal brain tissue challenging. Therefore, fluorescence-guided surgery is often used to improve visual identification of radiological tumor margins. The aim of this study was to evaluate the ability of recently developed molecularly targeted near-infrared (NIR) protease-activated probes to visualize GBM tissue and to compare the most promising candidate with the gold standard, 5-aminolevulinic acid (5-ALA). METHODS: Single-substrate probes 6QC-ICG and 6QC-Cy5 (cysteine cathepsin cleavable), double-substrate probes AG2-FNIR and AG2-Cy5 (cysteine cathepsin and caspase 3 cleavable), and 5-ALA were administered intravenously to mice with orthotopic tumors. Activation of the probes was also evaluated in cell cultures in vitro and in biopsy material from patients with GBM ex vivo. The tumor to normal brain tissue fluorescence ratio (TNR) was quantified in brain sections using preclinical and clinical visualization platforms, and in tissue homogenates and cell suspensions using spectrofluorimetry. Subcellular localization of the fluorophores was visualized by confocal microscopy. RESULTS: In vitro, the single-substrate probe 6QC-ICG was cleaved in glioma cells and macrophages, and the resulting fluorophore accumulated intracellularly. In experimental GBMs, both single- and double-substrate probes visualized tumor tissue, while in healthy brain tissue the signal was minimal. TNR was highest for 6QC-ICG and AG2-FNIR, but the signal intensity was higher for 6QC-ICG. Using xenograft and syngeneic mouse models, as well as human GBM biopsy material ex vivo, the authors confirmed the ability of 6QC-ICG to specifically visualize the glioma tissue using preclinical and clinical visualization platforms. Finally, a comparison with 5-ALA in animals coadministered with both compounds revealed a higher TNR for 6QC-ICG in experimental GBMs. CONCLUSIONS: The cysteine cathepsin-cleavable probe 6QC-ICG is activated by glioma cells and tumor-associated macrophages, leading to a high contrast between tumor and nontumorous brain tissue that is superior to that of the current standard, 5-ALA. In addition to a well-defined mechanism of action, protease-activated probes that use NIR fluorophores (e.g., indocyanine green) have the advantage of low absorption and scattering of the NIR light and lower tissue autofluorescence. These results suggest that 6QC-ICG has the potential to become the targeted agent in intraoperative detection of GBM tissue using fluorescence imaging.
- MeSH
- fluorescenční barviva MeSH
- glioblastom * diagnostické zobrazování patologie MeSH
- kyselina aminolevulová * MeSH
- lidé MeSH
- molekulární sondy MeSH
- myši MeSH
- nádorové buněčné linie MeSH
- nádory mozku * diagnostické zobrazování patologie MeSH
- optické zobrazování metody MeSH
- proteasy metabolismus MeSH
- zvířata MeSH
- Check Tag
- lidé MeSH
- myši MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- srovnávací studie MeSH
