Multimodal gadolinium fluoride nanoparticles belong to potential contrast agents useful for bimodal optical fluorescence and magnetic resonance imaging. However, the metallic nature of the nanoparticles, similarly to some paramagnetic iron oxides, might induce allergic and anaphylactic reactions in patients after administration. A reduction of these adverse side effects is a priority for the safe application of the nanoparticles. Herein, we prepared paramagnetic poly(4-styrenesulfonic acid-co-maleic acid) (PSSMA)-stabilized GdF3 nanoparticles with surface modified by Atto 488-labeled poly(styrene-grad-2-dimethylaminoethyl acrylate)-block-poly(2-dimethylaminoethyl acrylate) (PSDA-A488) with reactive amino groups for introduction of an additional imaging (luminescence) modality and possible targeting of anticancer drugs. The saturation magnetization of GdF3@PSSMA particles according to SQUID magnetometry reached 157 Am2 kg-1 at 2 K and magnetic field of 7 T. GdF3@PSSMA-PSDA-A488 nanoparticles were well tolerated by human cervical adenocarcinoma (HeLa), mouse bone marrow-derived mast cells (BMMC), and rat basophilic mast cells (RBL-2H3); the particles also affected cell morphology and protein tyrosine phosphorylation in mast cells. Moreover, the nanoparticles interfered with the activation of mast cells by multivalent antigens and inhibited calcium mobilization and cell degranulation. These findings show that the new multimodal GdF3-based nanoparticles possess properties useful for various imaging methods and might minimize mast cell degranulation incurred after future nanoparticle diagnostic administration.
- MeSH
- degranulace buněk MeSH
- krysa rodu rattus MeSH
- lidé MeSH
- mastocyty * MeSH
- myši MeSH
- nanočástice * MeSH
- polymery MeSH
- růstový diferenciační faktor 3 MeSH
- zvířata MeSH
- Check Tag
- krysa rodu rattus MeSH
- lidé MeSH
- myši MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
We report experimental results on damage induced by ionizing radiation to DNA origami triangles which are commonly used prototypes for scaffolded DNA origami nanostructures. We demonstrate extreme stability of DNA origami upon irradiation, which is caused by (i) the multi-row design holding the shape of the origami even after severe damage to the scaffold DNA and (ii) the reduction of damage to the scaffold DNA due to the protective effect of the folded structure. With respect to damage induced by ionizing radiation, the protective effect of the structure is superior to that of a naturally paired DNA double helix. Present results allow estimating the stability of scaffolded DNA origami nanostructures in applications such as nanotechnology, pharmacy or in singulo molecular studies where they are exposed to ionizing radiation from natural and artificial sources. Additionally, possibilities are opened for scaffolded DNA use in the design of radiation-resistant and radio-sensitive materials.
- MeSH
- DNA MeSH
- ionizující záření MeSH
- konformace nukleové kyseliny MeSH
- nanostruktury * MeSH
- nanotechnologie MeSH
- Publikační typ
- časopisecké články MeSH
The growing incidence of multidrug-resistant bacterial strains presents a major challenge in modern medicine. Antibiotic resistance is often exhibited by Staphylococcus aureus, which causes severe infections in human and animal hosts and leads to significant economic losses. Antimicrobial agents with enzymatic activity (enzybiotics) and phage therapy represent promising and effective alternatives to classic antibiotics. However, new tools are needed to study phage-bacteria interactions and bacterial lysis with high resolution and in real-time. Here, we introduce a method for studying the lysis of S. aureus at the single-cell level in real-time using atomic force microscopy (AFM) in liquid. We demonstrate the ability of the method to monitor the effect of the enzyme lysostaphin on S. aureus and the lytic action of the Podoviridae phage P68. AFM allowed the topographic and biomechanical properties of individual bacterial cells to be monitored at high resolution over the course of their lysis, under near-physiological conditions. Changes in the stiffness of S. aureus cells during lysis were studied by analyzing force-distance curves to determine Young's modulus. This allowed observing a progressive decline in cellular stiffness corresponding to the disintegration of the cell envelope. The AFM experiments were complemented by surface plasmon resonance (SPR) experiments that provided information on the kinetics of phage-bacterium binding and the subsequent lytic processes. This approach forms the foundation of an innovative framework for studying the lysis of individual bacteria that may facilitate the further development of phage therapy.
- MeSH
- bakteriofágy * MeSH
- lidé MeSH
- mikroskopie atomárních sil MeSH
- povrchová plasmonová rezonance MeSH
- stafylokokové infekce * MeSH
- Staphylococcus aureus MeSH
- zvířata MeSH
- Check Tag
- lidé MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
DNA nanodevices have been developed as platforms for the manipulation of gene expression, delivery of molecular payloads, and detection of various molecular targets within cells and in other complex biological settings. Despite efforts to translate DNA nanodevices from the test tube (in vitro) to living cells, their intracellular trafficking and functionality remain poorly understood. Herein, quantitative and super-resolution microscopy approaches were employed to track and visualise, with nanometric resolution, the molecular interactions between a synthetic DNA nanosensor and transcription factors in intracellular compartments. Specifically, fluorescence resonance energy transfer microscopy, fluorescence correlation spectroscopy, fluorescence lifetime imaging microscopy and multicolour single-molecule localisation microscopy were employed to probe the specific binding of the DNA nanosensor to the nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB). We monitored the mobility, subcellular localisation and degradation of the DNA nanosensor inside living prostate cancer PC3 cells. Super-resolution imaging enabled the direct visualisation of the molecular interactions between the synthetic DNA nanosensors and the NF-κB molecules in cells. This study represents a significant advance in the effective detection as well as understanding of the intracellular dynamics of DNA nanosensors in a complex biological milieu.
- MeSH
- DNA vazebné proteiny MeSH
- DNA MeSH
- lidé MeSH
- NF-kappa B * genetika metabolismus MeSH
- rezonanční přenos fluorescenční energie MeSH
- signální transdukce * MeSH
- Check Tag
- lidé MeSH
- mužské pohlaví MeSH
- Publikační typ
- časopisecké články MeSH
Biological effects of high-LET (linear energy transfer) radiation have received increasing attention, particularly in the context of more efficient radiotherapy and space exploration. Efficient cell killing by high-LET radiation depends on the physical ability of accelerated particles to generate complex DNA damage, which is largely mediated by LET. However, the characteristics of DNA damage and repair upon exposure to different particles with similar LET parameters remain unexplored. We employed high-resolution confocal microscopy to examine phosphorylated histone H2AX (gammaH2AX)/p53-binding protein 1 (53BP1) focus streaks at the microscale level, focusing on the complexity, spatiotemporal behaviour and repair of DNA double-strand breaks generated by boron and neon ions accelerated at similar LET values (~135 keV mum
- MeSH
- 53BP1 * chemie MeSH
- apoptóza MeSH
- dvouřetězcové zlomy DNA * MeSH
- fibroblasty účinky záření MeSH
- fluorescenční protilátková technika MeSH
- fosforylace MeSH
- histony * chemie MeSH
- ionizující záření MeSH
- konfokální mikroskopie * MeSH
- kultivované buňky MeSH
- lidé MeSH
- lineární přenos energie * MeSH
- oprava DNA MeSH
- Check Tag
- lidé MeSH
Here, we describe a novel polymer platform suitable for efficient diagnostics and potential theranostics based on
- MeSH
- doxorubicin aplikace a dávkování farmakokinetika MeSH
- experimentální nádory * diagnostické zobrazování farmakoterapie MeSH
- Jurkat buňky MeSH
- lidé MeSH
- MFC-7 buňky MeSH
- myši inbrední BALB C MeSH
- myši MeSH
- nádorové buněčné linie MeSH
- nosiče léků * chemie MeSH
- optické zobrazování * MeSH
- polymery * chemie MeSH
- pozitronová emisní tomografie * MeSH
- radionuklidy MeSH
- teranostická nanomedicína * MeSH
- tkáňová distribuce MeSH
- zirkonium MeSH
- zvířata MeSH
- Check Tag
- lidé MeSH
- myši MeSH
- ženské pohlaví MeSH
- zvířata MeSH
In this report, monodisperse upconversion NaYF4:Yb3+/Er3+ nanoparticles with superior optical properties were synthesized by the oleic acid-stabilized high-temperature co-precipitation of lanthanide chlorides in octadec-1-ene as a high-boiling organic solvent. To render the particles with biocompatibility and colloidal stability in bioanalytically relevant phosphate buffered saline (PBS), they were modified by using in-house synthesized poly(ethylene glycol)-neridronate (PEG-Ner), a bisphosponate. The NaYF4:Yb3+/Er3+@PEG nanoparticles showed excellent long-term stability in PBS and/or albumin without any aggregation or morphology transformation. The in vitro cytotoxicity of the nanoparticles was evaluated using primary fibroblasts (HF) and a cell line derived from human cervical carcinoma (HeLa). The particles were subsequently modified by using Bolton-Hunter-hydroxybisphosphonate to enable radiolabeling with 125I for single-photon emission computed tomography/computed tomography (SPECT/CT) bimodal imaging to monitor the biodistribution of the nanoparticles in non-tumor mice. The bimodal upconversion 125I-radiolabeled NaYF4:Yb3+/Er3+@PEG nanoparticles are prospective for near-infrared (NIR) photothermal/photodynamic and SPECT/CT cancer theranostics.
Efficient delivery of stabilized nucleic acids (NAs) into cells and release of the NA payload are crucial points in the transfection process. Here we report on the fabrication of a nanoscopic cellular delivery carrier that is additionally combined with a label-free intracellular sensor device, based on biocompatible fluorescent nanodiamond particles. The sensing function is engineered into nanodiamonds by using nitrogen-vacancy color centers, providing stable non-blinking luminescence. The device is used for monitoring NA transfection and the payload release in cells. The unpacking of NAs from a poly(ethyleneimine)-terminated nanodiamond surface is monitored using the color shift of nitrogen-vacancy centers in the diamond, which serve as a nanoscopic electric charge sensor. The proposed device innovates the strategies for NA imaging and delivery, by providing detection of the intracellular release of non-labeled NAs without affecting cellular processing of the NAs. Our system highlights the potential of nanodiamonds to act not merely as labels but also as non-toxic and non-photobleachable fluorescent biosensors reporting complex molecular events.
- MeSH
- buňky HT-29 MeSH
- DNA * MeSH
- lidé MeSH
- luminiscence MeSH
- myši inbrední DBA MeSH
- nanodiamanty * MeSH
- transfekce * MeSH
- zvířata MeSH
- Check Tag
- lidé MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
We show that fluorescent nanodiamonds (FNDs) are among the few types of nanosensors that enable direct optical reading of noncovalent molecular events. The unique sensing mechanism is based on switching between the negatively charged and neutral states of NV centers which is induced by the interaction of the FND surface with charged molecules.
