- 标题
- 摘要
- 关键词
- 实验方案
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Cellular Internalization-Induced Aggregation of Porous Silicon Nanoparticles for Ultrasound Imaging and Protein-Mediated Protection of Stem Cells
摘要： Nanotechnology employs multifunctional engineered materials in the nanoscale range that provides many opportunities for translational stem cell research and therapy. Here, a cell-penetrating peptide (virus-1 transactivator of transcription)–conjugated, porous silicon nanoparticle (TPSi NP) loaded with the Wnt3a protein to increase both the cell survival rate and the delivery precision of stem cell transplantation via a combinational theranostic strategy is presented. The TPSi NP with a pore size of 10.7 nm and inorganic framework enables high-efficiency loading of Wnt3a, prolongs Wnt3a release, and increases antioxidative stress activity in the labeled mesenchymal stem cells (MSCs), which are highly beneficial properties for cell protection in stem cell therapy for myocardial infarction. It is confirmed that the intracellular aggregation of TPSi NPs can highly amplify the acoustic scattering of the labeled MSCs, resulting in a 2.3-fold increase in the ultrasound (US) signal compared with that of unlabeled MSCs. The translational potential of the designed nanoagent for real-time US imaging–guided stem cell transplantation is confirmed via intramyocardial injection of labeled MSCs in a nude mouse model. It is proposed that the intracellular aggregation of protein drug–loaded TPSi NPs could be a simple but robust strategy for improving the therapeutic effect of stem cell therapy.
关键词： drug delivery,porous silicon,ultrasound imaging,cell protection,cell labeling
更新于2025-09-23 15:21:01
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<em>In Vivo</em> Two-photon Imaging of Cortical Neurons in Neonatal Mice
摘要： Two-photon imaging is a powerful tool for the in vivo analysis of neuronal circuits in the mammalian brain. However, a limited number of in vivo imaging methods exist for examining the brain tissue of live newborn mammals. Herein we summarize a protocol for imaging individual cortical neurons in living neonatal mice. This protocol includes the following two methodologies: (1) the Supernova system for sparse and bright labeling of cortical neurons in the developing brain, and (2) a surgical procedure for the fragile neonatal skull. This protocol allows the observation of temporal changes of individual cortical neurites during neonatal stages with a high signal-to-noise ratio. Labeled cell-specific gene silencing and knockout can also be achieved by combining the Supernova with RNA interference and CRISPR/Cas9 gene editing systems. This protocol can, thus, be used for analyzing the developmental dynamics of cortical neurons, molecular mechanisms that control the neuronal dynamics, and changes in neuronal dynamics in disease models.
关键词： Neuroscience,in vivo imaging,single-cell labeling,mouse,cerebral cortex,Newborn,two-photon
更新于2025-09-23 15:21:01
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Graphene-Enabled, Spatially Controlled Electroporation of Adherent Cells for Live-Cell Super-resolution Microscopy
摘要： The incorporation of exogenous molecules into live cells is essential for both biological research and therapeutic applications. In particular, for the emerging field of super-resolution microscopy of live mammalian cells, it remains a challenge to deliver tailored, often cell-impermeable, fluorescent probes into live cells for target labeling. Here, utilizing the outstanding mechanical, electrical, and optical properties of graphene, we report a facile approach that enables both high-throughput delivery of fluorescent probes into adherent mammalian cells and in situ super-resolution microscopy on the same device. ~90% delivery efficiencies are achieved for free dyes and dye-tagged affinity probes, short peptides, and whole antibodies, thus enabling high-quality super-resolution microscopy. Moreover, we demonstrate good spatiotemporal controls, which, in combination with the ready patternability of graphene, allow for the spatially selective delivery of two different probes for cells at different locations on the same substrate.
关键词： electroporation,graphene,intracellular delivery,live-cell labeling,super-resolution microscopy
更新于2025-09-23 15:19:57
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Biocompatible quantum dot-antibody conjugate for cell imaging, targeting and fluorometric immunoassay: crosslinking, characterization and applications
摘要： Quantum dots (QDs) are important fluorescent probes that offer great promise for bio-imaging research due to their superior optical properties. However, QDs for live cell imaging and the tracking of cells need improving labeling efficiency, and reducing more investigation to simplify processing procedures, chronic toxicity. In this study, QDs were functionalized with bovine serum albumin (BSA) via a chemical linker. Anti-human immunoglobulin antibodies were oxidized by sodium periodate to create reactive aldehyde groups for a spontaneous reaction with the amine groups of BSA-modified QDs. An antibody-labeled QD bioconjugate was characterized using agarose gel electrophoresis, dynamic light scattering, and zeta potential. Using fluorescence spectroscopy, we found that the fluorescence of QDs was retained after multiple conjugation steps. The cell-labeling function of the QD bioconjugate was confirmed using an image analyzer and confocal microscopy. The QD bioconjugate specifically targeted the human immunoglobulin on the membrane surface of recombinant cells. The QD bioconjugate applied in fluorometric immunoassay was effective for the quantitative analysis of human immunoglobulin in an enzyme-linked immunosorbent assay. The developed QD bioconjugate may offer a promising platform to develop biocompatible tools to label cells and quantify antibodies in the immunoassay.
关键词： Quantum dots,Bio-imaging,Fluorescent probes,Cell labeling,Fluorometric immunoassay
更新于2025-09-16 10:30:52
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Preparation and cell imaging of nitrogen-doped graphene quantum dot conjugated indomethacin
摘要： The nitrogen-doped graphene quantum dot conjugated indomethacin (N-GQD-IDM) was synthesized by an amide reaction. The results of FTIR indicated that the synthesis of N-GQD-IDM was successful. It was then co-cultured with MCF-7 cells, and obvious fluorescence was observed under a laser confocal scanning microscope. With the increase of incubation time, the material accumulated significantly in the cells and the fluorescence intensity of the cells was slightly improved. This compound could be suggested as a promising fluorescent probe in cancer cell labeling.
关键词： indomethacin,fluorescent probe,cancer cell labeling,nitrogen-doped graphene quantum dots
更新于2025-09-16 10:30:52
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Human Umbilical Cord Wharton's Jelly-derived Mesenchymal Stem Cells Labeled with Mn2+ and Gd3+ Co-doped CuInS2-ZnS Nanocrystals for Multi-modality Imaging in Tumor Mice Model
摘要： Mesenchymal stem cells (MSCs) therapy has recently received profound interest as a targeting-platform in cancer-theranostics due to inherent tumor-homing abilities. However, the terminal tracking of MSCs-engraftment by fluorescent in situ hybridization, immuno-histochemistry and flow-cytometry techniques to translate into clinics are still challenging due to dearth of inherent MSC-specific markers and FDA-approval for genetic-modifications of MSCs. To address this challenge, a cost-effective non-invasive imaging technology based on multi-functional nanocrystals (NCs) with enhanced-detection sensitivity, spatial-temporal resolution, deep-tissue diagnosis is needed to be developed to track the transplanted stem cells. A hassle-free labeling of human umbilical-cord Wharton’s-Jelly (WJ)-derived MSCs with Mn2+ and Gd3+ co-doped CuInS2-ZnS (CIS-ZMGS) NCs has been demonstrated in 2 h without requiring electroporation process or transfection agents. It has been found that, WJ-MSCs labeling did not affect their multi-lineage differentiation (adipocyte, osteocyte, chondrocyte), immuno-phenotypes (CD44+, CD105+, CD90+), protein (β-actin, vimentin, CD73, α-SMCA) and gene-expressions. Interestingly, CIS-ZMGS-NCs labeled WJ-MSCs exhibit near-infrared fluorescence (NIR) with quantum yield (QY) of 84%, radiant intensity ~3.999 x 1011 (p/sec/cm2/sr)/(μW/cm2), magnetic relaxivity (longitudinal r1=2.26 mM-1s-1, transverse r2=16.47 mM-1s-1) and X-ray attenuation (78 HU) potential for early non-invasive multi-modality imaging of a subcutaneous-melanoma in B16F10-tumor-bearing C57BL/6-mice in 6 h. The ex vivo imaging and inductively-coupled plasma mass-spectroscopy (ICP-MS) analyses of excised organs along with confocal-microscopy and immuno-fluorescence of tumor results also significantly confirmed positive-tropism of CIS-ZMGS-NCs labeled WJ-MSCs in the tumor-environment. Hence, we propose the magneto-fluorescent CIS-ZMGS-NCs labeled WJ-MSCs as a next-generation nano-bioprobe of three commonly used imaging-modalities for stem cells-assisted anti-cancer therapy and tracking tissue/organ regenerations.
关键词： multi-modality imaging,stem cell labeling,CuInS2-ZnS,in vivo tracking,microwave refluxing
更新于2025-09-12 10:27:22
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Performance of Fluorescent Cell-Labeling Dyes under Simulated Europa Mission Radiation Doses
摘要： We investigated the performance of several commonly used fluorescent dyes after exposure to a simulated Europa mission total ionizing radiation dose of 300 krad (3 kGy) applied using a 60Co source. Dyes irradiated in aqueous solution or as lyophilized powders were evaluated for absorbance and emission spectra, quantum yield, and where appropriate, ability to label cells or nucleic acids. Although some dyes showed significant increase or decrease in quantum yield with the dose, their spectra and cell-labeling properties remained essentially unchanged after irradiation in powder form. Irradiation in aqueous solution led to significantly greater changes, including a large blue shift in the DNA intercalator propidium iodide. These results suggest that many fluorescent probes are appropriate for use in astrobiological missions to Europa, but that SYTO9 and propidium iodide should be used with caution or not mixed with each other, as is commonly done in "Live/Dead" labeling applications.
关键词： Europa mission,fluorescent dyes,ionizing radiation,cell-labeling,astrobiology
更新于2025-09-04 15:30:14