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Light-Inducible Exosome-Based Vehicle for Endogenous RNA Loading and Delivery to Leukemia Cells
摘要： Exosomes are a novel and promising drug delivery platform because of their endogenous origin, stability, biocompatibility, and other unique features. As the efficient loading and delivery of long RNA to target cells for therapeutic purposes remains challenging, a new exosome-based RNA delivery system is proposed using a controllable RNA enrichment and releasing protocol. The system employs RNA aptamer–protein interactions and reversible light-inducible protein–protein interaction modules by remolding exosome producer cells. Endogenous microRNA 21 (miR-21) sponges, inhibitors of miR-21, are successfully enriched on the plasma membrane and are sorted into exosomes by the biogenesis of the exosomes. The loading capacity of miR-21 sponges is enhanced by 14-fold in the light-inducible loading system. In addition, targeted delivery of miR-21 to leukemia cells is achieved by modifying exosomes with the cholesterol-conjugated aptamer AS1411, resulting in significant cell apoptosis by blocking the function of miR-21 in leukemia cells. This work provides an exosome-based light-inducible vehicle to efficiently load and deliver long endogenous RNA, which can enable more RNA-based therapeutics for personalized cancer medicine.
关键词： miRNA sponge,leukemia,RNA enrichment,exosomes,reversible light-inducible vehicles,aptamers
更新于2025-09-23 15:23:52
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Selective, Quantitative, and Multiplexed Surfacea??Enhanced Raman Spectroscopy Using Aptamera??Functionalized Monolithic Plasmonic Nanogrids Derived from Crossa??Point Nanoa??Welding
摘要： Recent advances in surface-enhanced Raman spectroscopy (SERS) have resulted in multiplexing with unprecedented levels of sensitivity and selectivity in trace-amount detection. However, quantification of multiple trace-amount molecules with ng-level accuracy has yet to be demonstrated due to nonuniform distribution of SERS enhancement and random adsorption of molecules at low concentrations. While Raman reporter-free SERS is favorable for quantification in that the unique fingerprint spectra of molecules enable specific molecular identification, it has yet to be demonstrated due to poor reproducibility and insufficient SERS enhancement. Raman reporter-free multiplex SERS with highly accurate quantification is successfully realized by versatile aptamer-functionalized plasmonic Au nanogrids with uniform SERS enhancement. By cross-point nano-welding, monolithic Au nanogrids with excellent uniformity and high stability in aqueous media are produced. Raman reporter-free multiplex detection and highly accurate quantification of concentration and composition is realized at picomolar levels. As a demonstration, Au nanogrids functionalized with bisphenol A-specific aptamers successfully detect and quantify trace-amounts of bisphenol A (8.49 ng) from thermal receipt paper. Moreover, principal component analysis is applied to multiplex SERS spectra to establish a ternary composition map, which can potentially serve as a practical reference for future Raman reporter-free SERS.
关键词： plasmons,nanogrids,multiplexing,surface-enhanced Raman spectroscopy,aptamers
更新于2025-09-23 15:19:57
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Photo-Controlled Thermosensitive Electrochemiluminescence Hydrogel for Isocarbophos Detection
摘要： Endowing specificity and controllability with the electrochemiluminescence (ECL) thermosensitive hydrogels is vitally crucial to expand their sensing applications. Herein, a novel photo-controlled thermosensitive electrochemiluminescence hydrogel (PT-ECL hydrogel) sensing platform with sufficient simplicity, specificity and precise controllability, for the first time, is proposed, by the integration of Ru(bpy)3 2+ derivatives (signal reporter), split aptamers (recognition unites), and Au nanorods (AuNRs) (photothermal energy converter) into the poly(N-isopropylacrylamide) (pNIPAM) matrix. In the presence of the model target isocarbophos (ICP), the conjugation of two split-aptamers initiated the ECL-Resonance Energy Transfer (ECL-RET) between the Au nanorods and the Ru(bpy)3 2+ centers. Surprisingly, under the irradiation of near-infrared (NIR) light, the photothermal effect of AuNRs prompted the shrinkage of the hydrogel, resulting in the enhancement of the ECL-RET and further ~7 times signal amplification. Consequently, the PT-ECL hydrogel sensing platform performed well for ICP detection with a low detection limit of 20 pM (S/N=3) and wide linear range from 50 pM to 4 μM, with great stability and repeatability. Obviously, the results showed that AuNRs utilized in this paper served the role as not only the ECL-RET acceptor, but also the photothermal converter to prompt the phase change of the PT-ECL hydrogel precisely and simply controlled by NIR light. Use of the proposed PT-ECL hydrogel detection scheme is a first step toward enabling a newly upgraded highly sensitive, selective hydrogel-based assays and also paving way for the application of smart photothermal reagents.
关键词： split aptamers,Au nanorods,photo-controlled,electrochemiluminescence,isocarbophos detection,thermosensitive hydrogel
更新于2025-09-23 15:19:57
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Specific Biosensing Using DNA Aptamers and Nanopores
摘要： The multiplexed biosensing of target molecules with high specificity and accuracy is of fundamental importance in both biological research and medical diagnostics. In this paper, the working range of the recent nanopore-DNA carrier based method is extended by introducing a two-step assay using specific DNA aptamers. A signal translation step allows for binding of the target in physiological conditions before the nanopore measurements. Using protein encoded DNA carriers, the simultaneous detection of three targets spanning several orders of magnitude in molecular weight is demonstrated. The single-molecule method may be integrated into nanopore sensing devices for future applied research and point-of-care applications.
关键词： DNA carriers,multiplexed sensing,nanopores,physiological condition,aptamers
更新于2025-09-09 09:28:46
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Satellite-like Gold Nanocomposites for Targeted Mass Spectrometry Imaging of Tumor Tissues
摘要： We have developed a simple, rapid, high-throughput cancer diagnosis system using functional nanoparticles (NPs) consisting of poly(catechin) capped-gold NPs (Au@PC NPs) and smaller nucleolin-binding aptamer (AS1411) conjugated gold NPs (AS1411–Au NPs). The AS1411–Au NPs/Au@PC NP is used as a targeting agent in laser desorption/ionization mass spectrometry (LDI-MS)-based tumor tissue imaging. Self-assembled core-shell Au@PC NPs are synthesized by a simple reaction of tetrachloroaurate(III) with catechin. Au@PC NPs with a well-defined and dense poly(catechin) shell (~40?60 nm) on the surface of each Au core (~60?80 nm) are obtained through careful control of the ratio of catechin to gold ions, as well as the pH of the reaction solution. Furthermore, we have shown that AS1411-conjugated Au NPs (13-nm) self-assembled on Au@PC NP can from a satellite-like gold nanocomposite. The high density of AS1411–Au NPs on the surface of Au@PC NP enhances multivalent binding with nucleolin molecules on tumor cell membranes. We have employed LDI-MS to detect AS1411–Au NPs/Au@PC NPs labeled nucleolin-overexpressing MCF-7 breast cancer cells through the monitoring of Au cluster ions ([Aun]+; 1 ≤ n ≤ 3). The ultrahigh signal amplification from Au NPs through the formation of a huge number of [Aun]+ ions results in a sensing platform with a limit of detection of 100 MCF-7 cells mL?1. Further, we have applied the satellite-like AS1411–Au NPs/Au@PC NP nanocomposite as a labeling agent for tumor tissue imaging by LDI-MS. Our nanocomposite-assisted LDI-MS imaging platform can be extended for simultaneous analysis of different tumor markers on cell membranes when using different ligand-modified metal nanoparticles.
关键词： tissue imaging,aptamers,laser desorption/ionization mass spectrometry,self-assembly,gold nanocomposites
更新于2025-09-04 15:30:14
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Single-Molecule Kinetic Fingerprinting for the Ultrasensitive Detection of Small Molecules with Aptasensors
摘要： Aptamers have emerged as promising molecular tools for small-molecule analyte sensing. However, the performance of such aptasensors is generally limited by leakage since it has been difficult to completely suppress signal in the absence of analyte, resulting in a compromise between sensitivity and specificity. Here, we describe a methodology for the ultrasensitive detection of analytes combining aptasensors with single-molecule kinetic fingerprinting. A short, fluorescently labeled DNA probe is utilized to detect the structural changes upon ligand binding to the designed hairpin-shaped aptasensor probe. The Poisson statistics of binding and dissociation events of the DNA probe to single surface-immobilized aptasensor molecules is monitored by total internal reflection fluorescence microscopy, permitting the high-accuracy discrimination of the ligand bound and ligand-free states, resulting in zero background. The programmable dynamics of the hairpin enables fine-tuning of the hybridization kinetics of the fluorescent probe, rendering the acquisition time sufficiently flexible to optimize discrimination. Remarkable detection limits are achieved for a diverse set of analytes when spiked into chicken meat extract: the nucleotide adenosine (0.3 pM), the insecticide acetamiprid (0.35 pM), and the dioxin-like toxin PCB-77 (0.72 pM), which is superior to recently reported aptasensors. Our generalizable method significantly improves the performance of aptasensors, with the potential to extend to other molecular biomarkers.
关键词： Aptamers,Aptasensors,Single-molecule kinetic fingerprinting,Ultrasensitive detection,Small molecules
更新于2025-09-04 15:30:14