- 标题
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- 实验方案
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An Enzyme-Free MicroRNA Assay Based-on Fluorescence Counting of Click Chemical Ligation-Illuminated Magnetic Nanoparticles with Total Internal Reflection Fluorescence Microscopy
摘要： MicroRNAs (miRNAs) have been considered as promising cancer biomarkers. However, the simple but sensitive detection of low levels of miRNAs in biological samples still remains challenging. Herein, we wish to report an entirely enzyme-free, simple and highly sensitive miRNA assay based on the counting of cycling click chemical ligation (3CL)-illuminated fluorescent magnetic nanoparticles (MNPs) with a total internal reflection fluorescence microscopy (TIRFM). In this strategy, each miRNA molecule can trigger many cycles of click chemical ligation reactions to produce plentiful ligated oligonucleotides (ODNs) with both 5’-biotin and 3’-fluorophore, resulting in efficient signal amplification. It is worth noting that only the ligated ODNs can bring fluorophores onto streptavidin-functionalized MNPs (STV-MNPs). Notably, merely 10 fluorescent molecules on each 50 nm MNP can make it bright enough to be clearly visualized by the TIRFM, which can significantly improve the detection sensitivity for miRNA. Through fluorescence counting of individual MNPs and integrating their fluorescence intensities, the amount of target miRNA can be quantitatively determined. This miRNA assay can be accomplished in a mix-and-read manner just by simply mixing the enzyme-free 3CL reaction system with the MNPs before TIRFM imaging, which avoids tedious immobilization, washing and purification steps. Despite the extremely simple operation, this strategy exhibits high sensitivity with a quite low detection limit of 50 fM target miRNA as well as high specificity to well discriminate miRNA sequences with a single-base variation. Furthermore, the applicability of this method in real biological samples is also verified through the accurate detection of miRNA target in cancer cells.
关键词： click chemistry,microRNA,TIRFM,magnetic nanoparticle,fluorescence counting
更新于2025-09-23 15:21:21
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Enhanced modulation of magnetic field on surface plasmon coupled emission (SPCE) by magnetic nanoparticles
摘要： The obvious enhancement effect of magnetic nanoparticles (MNPs) introduced in Cr/Co/Cr/Au substrate on the pulsed magnetic field-modulated surface plasmon coupled emission (SPCE) was investigated, and the observed enhancement factor was 4 comparing with the magnetic field modulated SPCE without MNPs. This is the new observation for the magnetic field-modulated SPCE in fluorescence signal and helps to build the new SPCE based stimulus-response system.
关键词： Magnetic field modulation,Magnetic nanoparticle,Surface plasmon coupled emission (SPCE),Fluorescence enhancement,Biosensor
更新于2025-09-16 10:30:52
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Magnetic iron oxide nanoparticles/10-hydroxy camptothecin co-loaded nanogel for enhanced photothermal-chemo therapy
摘要： Iron oxide nanoparticle is a promising nano-biomaterial for treating iron deficiency, or as drug carriers and contrast agent as well as stimulator to elicit ROS generation. However, because of their intrinsic structure, therapeutic agents are hard to be loaded by them alone. Nanogel is a promising candidate for co-loading of iron oxide and therapeutic drug, due to its network structure and permeability. In this study, we use pre-prepared nanogel as surfactant to co-load hydrophobic magnetic nanoparticles (MNPs) and anti-cancer drug (10-hydroxy camptothecin, HCPT) to construct MNPs/HCPT-nanogel for cancer diagnosis and therapy. By in vitro and in vivo evaluation, we reveal that the obtained MNPs/HCPT-nanogel are stable in aqueous environment and can be served as drug delivery system to efficiently inhibit the tumor growth as well as MRI contrast agent for MR imaging. The introduction of MNPs elicits the generation of ROS with the presence of macrophage, which can further inhibit the growth of cancer cell. Furthermore, the introduction of extra-magnetic field can further enhance the enrichment of MNPs/HCPT-nanogel in the tumor site, which further improves the chemotherapeutic outcome. Besides, the obtained MNP/HCPT-nanogel can be used as nanocarrier for photothermal therapy for its absorption at NIR region. With the combination of PTT and chemotherapy, not only can the growth primary tumor be inhibited, but also the metastasis can be alleviated. It demonstrates that the MNP/HCPT-nanogel can be served as a promising candidate for cancer PTT/chemotherapy to inhibit tumor growth and alleviate metastasis.
关键词： Cancer diagnosis,Biomaterials,Photothermal therapy,Nanogel,Magnetic nanoparticle,10-Hydroxy camptothecin
更新于2025-09-10 09:29:36
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Nanoparticle-Based Imaging of Clinical Transplant Populations Encapsulated in Protective Polymer Matrices
摘要： A recent clinical trial proves that autologous olfactory mucosal cell (OMC) transplantation improves locomotion in dogs with naturally occurring spinal injuries comparable to human lesions. However, not all dogs respond to the treatment, likely due to the transplantation procedures involving injections of cell suspensions that are associated with cell death, uneven cell distribution, and cell washout. Encapsulating cells in protective hydrogel matrices offers a tissue engineering solution to safely achieve 3D growth of viable transplant cells for implantation into injury sites, to improve regenerative outcomes. It is shown for the first time that canine OMCs (cOMCs) can be propagated with high viability in 3D collagen matrices. Further, a method to incorporate cOMCs pre-labeled with clinical-grade iron oxide nanoparticles into the constructs is described. Intraconstruct labeled cells are visualized using magnetic resonance imaging, offering substantial promise for in vivo tracking of cOMCs delivered in protective matrices.
关键词： magnetic nanoparticle,canine olfactory mucosal cell,cell transplantation,hydrogel,spinal injury
更新于2025-09-04 15:30:14