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A Label-free Platform for Identification of Exosomes from Different Sources
摘要： Exosomes contain cell- and cell-state-specific cargos of proteins, lipids, and nucleic acids and play significant roles in cell signaling and cell–cell communication. Current research into exosome-based biomarkers has relied largely on analyzing candidate biomarkers, i.e., specific proteins or nucleic acids. However, this approach may miss important biomarkers that are yet to be identified. Alternative approaches are to analyze the entire exosome system, either by “omics” methods or by techniques that provide “fingerprints” of the system without identifying each individual biomolecule component. Here, we describe a platform of the latter type, which is based on surface-enhanced Raman spectroscopy (SERS) in combination with multivariate analysis, and demonstrate the utility of this platform for analyzing exosomes derived from different biological sources. First, we examined whether this analysis could use exosomes isolated from fetal bovine serum using a simple, commercially available isolation kit or necessitates the higher purity achieved by the “gold standard” ultracentrifugation/filtration procedure. Our data demonstrate that the latter method is required for this type of analysis. Having established this requirement, we rigorously analyzed the Raman spectral signature of individual exosomes using a unique, hybrid SERS substrate made of a graphene-covered Au surface containing quasi-periodic array of pyramids. To examine the source of the Raman signal, we used Raman mapping of low and high spatial resolution combined with morphological identification of exosomes by scanning electron microscopy. Both approaches suggested that the spectra were collected from single exosomes. Finally, we demonstrate for the first time that our platform can distinguish among exosomes from different biological sources based on their Raman signature, a promising approach for developing exosome-based fingerprinting. Our study serves as a solid technological foundation for future exploration of the roles of exosomes in various biological processes and their use as biomarkers for disease diagnosis and treatment monitoring.
关键词： surface-enhanced Raman spectroscopy,graphene,biomarker,exosome,principal component analysis
更新于2025-09-23 15:22:29
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Exosomes Derived From Mesenchymal Stem Cells Modulate miR-126 to Ameliorate Hyperglycemia-Induced Retinal Inflammation Via Targeting HMGB1
摘要： PURPOSE. In this study, we aim to investigate whether mesenchymal stem cell (MSC)-derived exosomes (MSC-Exos) could regulate hyperglycemia-induced retinal inflammation by transferring microRNA-126 (miR-126). METHODS. MSC-Exos were isolated from the media of human umbilical cord-derived mesenchymal stem cells (hUCMSCs), and this isolation was followed by the transfer of miR-126. MSC-Exos or MSC-Exos overexpressing miR-126 were intravitreally injected into diabetic rats in vivo and were cocultured with high glucose-affected human retinal endothelial cells (HRECs) in vitro. Plasma samples were obtained from the vitreous of rats and from HREC cells after treatment for ELISA assay. Retinal sections were examined using immunohistochemistry. RT-PCR and Western blotting were conducted to assess the levels of high-mobility group box 1 (HMGB1), NLRP3 inflammasome, and NF-jB/P65 in retinas and HRECs. RESULTS. Our results showed that hyperglycemia greatly increased inflammation in diabetic rats or HRECs exposed to high glucose, increasing the levels of caspase-1, interleukin-1b (IL-1b) and IL-18. The administration of MSC-Exos could effectively reverse this reaction. Compared to control MSC-Exos, MSC-Exos overexpressing miR-126 more successfully suppressed the HMGB1 signaling pathway and suppressed inflammation in diabetic rats. The administration of miR-126-expressing MSC-Exos significantly reduced high glucose-induced HMGB1 expression and the activity of the NLRP3 inflammasome in HRECs. CONCLUSIONS. miR-126 expression in MSC-Exos reduces hyperglycemia-induced retinal inflammation by downregulating the HMGB1 signaling pathway.
关键词： HMGB1,exosome,NLRP3 inflammasome,miR-126,mesenchymal stem cell
更新于2025-09-19 17:15:36
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Near-Infrared Afterglow Semiconducting Nano-polycomplexes for Multiplex Differentiation of Cancer Exosomes
摘要： As nanoscaled extracellular vehicles inheriting genetic and protein information from source cells, detection of exosomes is promising for early diagnosis of cancer. However, optical sensors with high specificity and low medium background remain challenging for detection of exosomes. We herein develop the first luminescent nanosensor that bypasses real-time light excitation for multiplex differentiation of cancer exosomes. Such an afterglow luminescent nanosensor is composed of a near-infrared (NIR) semiconducting polyelectrolyte (ASPN) electrostatically complexed with a quencher-tagged aptamer. The afterglow signal of the nanocomplex (ASPNC) is initially quenched due to the efficient electron transfer between ASPN and the quencher. However, the presence of aptamer-targeted exosome increases ASPN/quencher distance, turning on afterglow signal. Because the afterglow detection is conducted after cessation of light excitation, the sample background signal is greatly minimized, affording the limit of detection that is nearly two orders of magnitude lower than fluorescence detection in cell culture medium. More importantly, ASPNC can be easily tailored to detect different exosomal proteins simply by changing the sequence of aptamer. Such a structural versatility of ASPNC enables orthogonal analysis of multiple exosome samples, potentially permitting accurate identification of the cellular origin of exosomes for cancer diagnosis.
关键词： optical imaging,semiconducting polymer,nanomaterials,biosensor,exosome
更新于2025-09-19 17:15:36
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Visible Light-Driven Self-Powered Device Based on a Straddling Nano-Heterojunction and Bio-Application for the Quantitation of Exosomal RNA
摘要： This paper reports the design and fabrication of a self-powered biosensing device based on TiO2 nanosilks (NSs)@MoS2 quantum dots (QDs) and demonstrates a bio-application for the quantitative detection of exosomal RNA (Homo sapiens HOXA distal transcript antisense RNA (HOTTIP)). This self-powered device features enhanced power output, compared to TiO2 NSs alone. This is attributed to the formation of a heterojunction structure with suitable band offset derived from the hybridization between TiO2 NSs and MoS2 QDs, i.e., the straddling (Type I) band alignment. The sensitization effect and excellent visible light absorption provided by MoS2 QDs can prolong interfacial carrier lifetime and improve energy conversion efficiency. This self-powered biosensing device has been successfully applied in quantitative HOTTIP detection through effective hybridization between a capture probe and HOTTIP. The successful capture of HOTTIP leads to a sequential decrease in power output, which is utilized for ultrasensitive quantitative HOTTIP detection, with a linear relationship of power output change vs. logarithm of HOTTIP concentration ranging from 5 fg/mL to 50000 ng/mL and a detection limit as low as 5 fg/mL. This TiO2 NSs@MoS2 QDs-based nanomaterial has excellent potential for a superior self-powered device characterized by economical and portable self-powered biosensing. Moreover, this self-powered, visible light-driven device shows promising applications for cancer bio-marker quantitative detection.
关键词： self-power,gastric cancer,heterojuncture,TiO2@MoS2,exosome,homo sapiens HOXA distal transcript antisense RNA(HOTTIP)
更新于2025-09-19 17:15:36
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Label-free characterization of exosome via surface enhanced Raman spectroscopy for the early detection of pancreatic Cancer
摘要： Pancreatic cancer is a highly lethal malignancy. Lack of early diagnostic markers makes timely detection of pancreatic cancer a highly challenging endeavor. Exosomes have emerged as information-rich cancer specific biomarkers. However, characterization of tumor-specific exosomes has been challenging. This study investigated the proof-of principal that exosomes could be used for the detection of pancreatic cancer. Label-free analysis of exosomes purified from normal and pancreatic cancer cell lines was performed using surface enhanced Raman Spectroscopy (SERS) and principal component differential function analysis (PC-DFA), to identify tumor-specific spectral signatures. This method differentiated exosomes originating from pancreatic cancer or normal pancreatic epithelial cell lines with 90% accuracy. The cell line trained PC-DFA algorithm was next applied to SERS spectra of serum-purified exosomes. This method exhibited up to 87% and 90% predictive accuracy for HC and EPC individual samples, respectively. Overall, our study identify utility of SERS spectral signature for deciphering exosomal surface signature.
关键词： surface enhanced Raman spectroscopy,liquid biopsy,Pancreatic cancer,exosome,label-free
更新于2025-09-04 15:30:14
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Exosome-like Nanozyme Vesicles for H2O2-responsive Catalytic Photoacoustic Imaging of Xenograft Nasopharyngeal Carcinoma
摘要： Photoacoustic imaging (PAI) is an attractive imaging modality, which is promising for clinical cancer diagnosis due to its advantages on deep tissue penetration and fine spatial resolution. However, few tumor catalytic/responsive PAI strategies are developed. Here, we design an exosome-like nanozyme vesicle for in vivo H2O2-responsive PAI of nasopharyngeal carcinoma (NPC). The intrinsic peroxidase-like activity of graphene quantum dot nanozyme (GQDzyme) effectively converts the 2,2’-azino-bis (3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) into its oxidized form in the presence of H2O2. The oxidized ABTS exhibits strong near-infrared (NIR) absorbance, rendering it to be an ideal contrast agent for PAI. Thus, GQDzyme/ABTS nanoparticle is a novel type of catalytic PAI contrast agent which is sensitive to H2O2 produced from NPC cells. Furthermore, we develop an approach to construct exosome-like nanozyme vesicle via biomimetic functionalization of GQDzyme/ABTS nanoparticle with natural erythrocyte membrane modified with folate acid. In vivo animal experiments demonstrated that, this exosome-like nanozyme vesicle effectively accumulated in NPC and selectively triggered catalytic PAI for NPC. In addition, our nanozyme vesicle exhibits excellent biocompatibility and stealth ability for long blood circulation. Together, we demonstrate that GQDzyme/ABTS based exosome-like nanozyme vesicle is an ideal nanoplatform for developing deep-tissue tumor-targeted catalytic PAI in vivo.
关键词： photoacoustic imaging,nasopharyngeal carcinoma,H2O2-responsive,graphene quantum dot nanozyme,exosome-like vesicle,erythrocyte membranes
更新于2025-09-04 15:30:14