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过滤筛选
- 2018
- electromagnetic pulse
- cell proliferation
- cell membrane permeability
- cell response to electromagnetic stress
- apoptosis
- cancer therapy
- necrosis
- Intelligent Medical Engineering
- V.N. Karazin Kharkiv National University
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A 1,8 Naphthalimide anchor Rhodamine B Based FRET Probe for Ratiometric Detection of Cr3+ion in Living Cells
摘要： A 2-(1,3-dioxo-1H-benzo[de]isoquinolin-2(3H)-yl)acetaldehydeanchored rhodamine B based probe, RDNAP detects Cr3+ ion by fluorescence resonance energy transfer (FRET) process in aqueous buffered acetonitrile media (7:3, v/v). Conversely, conjugation of 2-(1,3-dioxo-6-(piperidin-1-yl)-1H-benzo[de]isoquinolin-2(3H)-yl)acetaldehyde with rhodamine B provides another probe, RDNAP-PY that undergoes Cr3+assisted ratiometric fluorescence and colorimetric change in the same media. RDNAP-PY provides higher FRET efficiency and detects as low as 1.81×10?6 M Cr3+with an association constant, 15.9 × 104 M-1. Other common ions do not interfere. RDNAP-PY efficiently images intracellular Cr3+ in live Hep3B, MCF-7, HeLa, SiHa and HEK 293T cells under fluorescence microscope in a ratiometric and time dependent manner. 1H NMR titration and DFT studies strongly support experimental findings.
关键词： 1,8 Naphthalimide,Live cell imaging,Ratiometric probe,fluorescence resonance energy transfer,DFT calculation
更新于2025-09-09 09:28:46
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Imaging of endogenous hydrogen peroxide during the process of cell mitosis and mouse brain development with a near-infrared ratiometric fluorescent probe
摘要： Hydrogen peroxide (H2O2) is emerging as a new second messenger, which plays vital roles in intracellular signaling, thereby triggering physiological variations in terms of proliferation, differentiation, and migration. As known, cell mitosis has closely association to the intracellular level of H2O2, which contribute to the significant effects on the brain development, especially during the critical period of immaturity. Unfortunately, imaging H2O2 in mammalian brain is still challenging. Herein, to further investigate the biological roles of endogenous H2O2 in cells mitosis, we develop a near-infrared ratiometric fluorescent probe Cy-PFS for specifically imaging of endogenous H2O2 in cells and in vivo. Employing the probe Cy-PFS, we examine the critical effects of endogenous H2O2 on cells proliferation in live hippocampal neurons cells, our results provide strong evidences for H2O2 signaling in cell mitosis through growth factor signaling. Furthermore, we successfully demonstrate the close association of endogenous H2O2 level changes with the brain development at various stages. We envision that this present probe has potential as a promising useful chemical imaging tool for exploring the roles of H2O2 in cell mitosis.
关键词： cell mitosis,Hydrogen peroxide,endogenous H2O2,brain development,near-infrared ratiometric fluorescent probe
更新于2025-09-09 09:28:46
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ZnO nanoparticles modified with an amphipathic peptide show improved photoprotection in skin
摘要： ZnO nanoparticles of different sizes were functionalized with an amphipathic peptide and its effect on nanoparticle stabilization and UV photoprotective activity was studied in this article. The peptide modified nanoparticles exhibited lower aggregation, significant reduction in Zn2+ leaching in-vitro and even inside the cells for smaller particle sizes, reduced photocatalytic activity and reduced cellular toxicity under UV-B treated conditions. In addition, the peptide modified 60 nm sized ZnO nanoparticles showed lower genotoxicity, lower oxidative stress induction levels, less DNA damage responses and less immunogenic potential than the bare counterparts in presence of UV-B rays. They localized more in the stratum corneum and epidermis ex-vivo indicating better retention in epidermis and demonstrated improved UV-B protection and/or skin integrity in SKH-1 mice in-vivo as compared to unmodified nanoparticles and commercial UV protective agents tested. To our knowledge, this is the first report on application of peptide modified ZnO nanoparticles for improved photoprotection.
关键词： UV-B rays,ZnO nanoparticles,cytotoxicity,cell penetrating peptide,photoprotection
更新于2025-09-09 09:28:46
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Micro-patterned cell orientation of cyanobacterial liquid-crystalline hydrogels
摘要： Control of cell extension direction is crucial for the regeneration of tissues, which are generally composed of oriented molecules. The scaffolds of highly-oriented liquid crystalline polymer chains were fabricated by casting cyanobacterial mega-saccharides, sacran, on parallel-aligned micrometer bars of polystyrene (PS). Polarized microscopy revealed that the orientation was in transverse direction to the longitudinal axes of the PS bars. Swelling behavior of the micro-patterned hydrogels was dependent on the distance between the PS bars. The mechanical properties of these scaffolds were dependent on the structural orientation; additionally, the Young’s moduli in the transverse direction were higher than those in the parallel direction to the major axes of the PS bars. Further, fibroblast L929 cells were cultivated on the oriented scaffolds to be aligned along the orientation axis. L929 cells cultured on these scaffolds exhibited uniaxial elongation.
关键词： Cell orientation,Liquid crystal hydrogels,Micropatterned scaffolds,Cyanobacteria,Sulfated polysaccharides
更新于2025-09-09 09:28:46
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Media Dependent Switching of Selectivity and Continuous Near Infrared Turn-on Fluorescence Response through Cascade Interactions from Noncovalent to Covalent Binding for Detection of Serum Albumin in Living Cells
摘要： Abnormal level of proteins is proved to be associated with diseases. Thus, protein sensing is helpful for clinical diagnosis and therapy. However, there is a great variety of protein species and relatively low concentration of each protein in complicated biological systems including other non-protein biomolecules. Therefore, it remains challenging to develop an effective method for detecting protein with high selectivity and sensitivity. Herein, a new self-assembly method based on a robust dye SQSS of which two squaraine molecules were conjugated through disulfide bond was developed for highly selective and sensitive detection of serum albumin (SA) in aqueous solution and live cells. SQSS can self-assemble into “compact” aggregates, offering “inert” disulfide group and very low background fluorescence through the combination of aggregation quenching and homogeneous fluorescence resonance energy transfer (homoFRET) quenching. The response of SQSS to SA undergoes two cascade stages. At the first stage, SA drives the compact assemblies of SQSS to form loose ones with fast speed (30 s) through noncovalent interaction, resulting in the enhancement of fluorescence to some extent. In this loose assembly state, the disulfide bond in SQSS is reactive. At the second stage, the Cys34 in SA slowly induced further disassembly through covalent binding with reactive disulfide bond, resulting in fluorescence further increasing and SQSS labeling to SA that cannot be displaced by site binding ligands of SA. The self-assemblies of SQSS can selectively detect SA with continuous near infrared (NIR) turn-on fluorescence response in 100% aqueous buffer solution. In addition, SQSS showed the potential application of imaging SA in living cells. On the other hand, the loose assembly state of SQSS was also achieved in aqueous solution with 20% CH3CN. In this media, thiol-containing glutathione (GSH) caused the disassembly of SQSS with turn-on fluorescence response through interaction with disulfide bond. SQSS can selectively recognize GSH over other amino acids even in the presence of other sulfhydryl amino acids. As a proof-of-concept method, the molecular self-assembly through multi-steps interactions would provide an ideal strategy for detection and live-cell imaging of bio-related molecules with high selectivity and signal-to-noise ratio.
关键词： squaraine dyes,disulfide linkage,glutathione,live-cell imaging,serum albumin,self-assemblies,noncovalent and covalent interactions
更新于2025-09-09 09:28:46
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Shedding light on photodynamic therapy for basal cell carcinoma
摘要： The recognition of photodynamic therapy (PDT) as an effective treatment of cancers was due, in large part, to the studies of Thomas Dougherty and his colleagues at Roswell Park Cancer Institute in Buffalo, NY, started in the 1970s.1 In those studies, intravenous porphyrin derivatives and visible light were used. Topical PDT treatment, currently widely performed in dermatology, uses topically applied 5-aminolaevulinic acid (ALA) or ALA esters.2,3 ALA is converted to protoporphyrin IX in the epidermis. On exposure of protoporphyrin IX to its absorption spectrum in the visible light range, oxygen-dependent phototoxic reaction occurs resulting in cytotoxicity.
关键词： cosmesis,basal cell carcinoma,photodynamic therapy,treatment,dermatology
更新于2025-09-09 09:28:46
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Loss of horizontal macular ganglion cell complex asymmetry: an optical coherence tomography indicator of chiasmal compression
摘要： Objective To estimate the macular ganglion cell complex (GCC) asymmetry in patients with suprasellar tumours, to compare its diagnostic performance to the nasal GCC thickness and visual field (VF) and to investigate how the parameters correlate with magnetic resonance imaging (MRI) findings. Methods and analysis Cross-sectional study of patients with suprasellar tumours affecting the optic chiasm. Macular optical coherence tomography (OCT) scans were evaluated for nasal GCC sector thinning and loss of normal GCC asymmetry between corresponding nasal-temporal sectors. Equivalently, VFs were analysed for defects compatible with chiasm dysfunction. The relationship between optic chiasm and tumour was measured on MRI. results Thirty-three eyes of 33 patients were included. There were OCT findings in 14 eyes. Nasal GCC thinning was found in 9 eyes and loss of GCC asymmetry in 12 eyes; the two parameters were not significantly different with respect to number of positive findings (p=0.45). Loss of GCC asymmetry, however, occurred in 5 eyes among 24 without GCC thinning (proportion 0.21; 95% confidence interval 0.071 to 0.42). In 8 eyes, VF indicated pathology; of these, 7 had concurring OCT findings. The prevalence of OCT and VF findings increased significantly with suprasellar tumour extension on MRI. Conclusion The diagnostic capabilities of nasal GCC thinning and loss of GCC asymmetry were comparable, whilst their complementary performances increased the proportion of eyes in which OCT suggested compression. The prevalence of both OCT and VF findings grew with suprasellar tumour extension. In several cases, however, structural findings on OCT preceded detectable VF deficits.
关键词： suprasellar tumours,visual field,optical coherence tomography,chiasmal compression,macular ganglion cell complex
更新于2025-09-09 09:28:46
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Signal transmission at invaginating cone photoreceptor synaptic contacts following deletion of the presynaptic cytomatrix protein Bassoon in mouse retina
摘要： A key feature of the mammalian retina is the segregation of visual information in parallel pathways, starting at the photoreceptor terminals. Cone photoreceptors establish synaptic contacts with On bipolar and horizontal cells at invaginating, ribbon-containing synaptic sites, whereas Off bipolar cells form flat, non-ribbon-containing contacts. The cytomatrix protein Bassoon anchors ribbons at the active zone, and its absence induces detachment of ribbons from the active zone. In this study we investigate the impact of a missing Bassoon on synaptic transmission at the first synapse of the visual system. Release properties of cone photoreceptors were studied in wild-type and mutant mouse retinae with a genetic disruption of the presynaptic cytomatrix protein Bassoon using whole-cell voltage-clamp recordings. Light and electron microscopy revealed the distribution of Ca2+ channels and synaptic vesicles, respectively, in both mouse lines. Whole-cell recordings from postsynaptic horizontal cells of the two mouse lines showed that the presence of Bassoon (and a ribbon) enhanced the rate of exocytosis during tonic and evoked release by increasing synaptic vesicle pool size and replenishment rate, while at the same time slowing synaptic vesicle release. Furthermore, the number of Cav1.4 channels and synaptic vesicles was significantly higher at wild-type than at Bassoon mutant synaptic sites. The results of our study demonstrate that glutamate release from cone photoreceptor terminals can occur independent of a synaptic ribbon, but seems restricted to active zones, and they show the importance of a the synaptic ribbon in sustained and spatially and temporally synchronized neurotransmitter release.
关键词： signal transmission,retina,cone photoreceptor,horizontal cell,ribbon synapse,Bassoon
更新于2025-09-09 09:28:46
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Multimodal Imaging in Lung Cancer: It Is Time to Change
摘要： The imaging techniques can be classified into two main groups: Structural/morphological imaging (SMI), which includes X rays (XR), computed tomography (CT), ultrasounds (US) as well as some varieties of magnetic resonance (MRI), and shows anatomic-morphological aspects, and molecular imaging (MI), which includes nuclear medicine (SPECT, PET), fMRI, optical and nanosystems techniques, and provides information about biochemistry/biological activity, often before structural changes. According to Society of Nuclear Medicine and Molecular Imaging, MI “is the visualization, characterization, and measurement of biological processes at the molecular and cellular levels in humans and other living systems”. MI procedures are noninvasive, safe and painless. Its sensitivity is greater than SMI, but it lacks anatomical detail, which has led to the development of multimodal imaging, combining structural and molecular techniques, widely used at present in daily practice. The pillars of MI are biochemistry/biology, instrumentation and software, and its cycle is the following: study of biology/biochemistry of a process, establishment/definition of specific targets, and development of tracers, preclinical imaging, histological validation and finally clinical imaging. This new concept led to the individualized diagnostic and treatment, being the patient the center of the medical activity. “As opposed to the doctor-centric, curative model of the past, the future is going to be patient-centric and proactive” said Dr. Zerhouni (NIH Medline Plus Winter 2007). The doctor must adapt to the needs of the own patient and this fact requires a true change of heart, because MI is intimately tied to the biology of the disease to analyzing. A new and strong interrelationship came into being: a bidirectional system biology-imaging that will allow to be much more effective in the daily practice, not only in relation to diagnosis (specific and early), but also with therapy (guide cancer treatment selection and evaluate early treatment response). There is an absolute necessity to lock the two together. Likewise, in the future the biology of a disease will indicate us what is the most adequate imaging technique and vice versa. In this regard, we know that in non-small cell lung cancer (NSCLC), ALK+ status is associated with distinct characteristics at CT imaging (CT radiogenomic characterization) [1], and that in lung adenocarcinomas 18F-FDG uptake values are related with expression levels of cellular Glucose Transporters and EGFR mutations. For this reason, different EGFR mutations correlate with different FDG uptake values.
关键词： Small Cell Lung Cancer,PET,Biomarkers,CT,MRI,Lung Cancer,Molecular Imaging,Multimodal Imaging,Non-Small Cell Lung Cancer,Structural/Morphological Imaging
更新于2025-09-04 15:30:14
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Micropatterning of Porous Silicon Bragg Reflectors With Poly(Ethylene Glycol) to Fabricate Cell Microarrays: Towards Single Cell Sensing
摘要： The work presented here describes the development of optical label-free biosensor based on PSi Bragg reflector to study heterogeneity in single cells. Photolithographic patterning of poly(ethylene glycol) hydrogel with photoinitiator was employed on RGD peptide-modified PSi to create micropatterns with cell adhesive and cell repellent areas and J774 macrophage cells were incubated to form cell microarrays and single cell arrays. Moreover, cells on the microarrays were lysed osmotically with Milli-Q? water and the infiltration of cell lysate into the porous matrix was monitored by measuring the red shift in the reflectivity. On average, the magnitude of red shift increased with the increase in the number of cells on the micropatterns. The red shift from the spots with single cells varied from spot to spot emphasizing the heterogeneous nature of the individual cells.
关键词： porous silicon (PSi),cell patterning,cell lysis,label-free biosensing,poly(ethylene glycol (PEG) hydrogel
更新于2025-09-04 15:30:14