Nanoparticle Size Analyzer Research Articles

Tumor-derived Exosomes Induced M2 Macrophage Polarization and Promoted the Metastasis of Osteosarcoma Cells Through Tim-3

Osteosarcoma, the most prevalent primary malignancy of the bone, is often presented with high-grade subclinical metastatic disease that metastasizes at very early stages. Exosomes, as molecular information carriers, may play a potent role in the occurrence and development of tumors through oncogenic molecular reprogramming of tumor-associated macrophages (TAMs). In this study, we will investigate the effect of osteosarcoma-derived exosomes on the polarization of TAMs and decipher its underlying molecular mechanism. Osteosarcoma-derived exosomes from MG63cells were isolated and characterized by transmission electron microscopy, and nano-particle size analysis. Double fluorescence staining was performed to confirm the macrophages phagocytosis of exosomes. Western blot, qRT-PCR, and transwell assays were conducted to assess the effect of exosomes on migration, invasion, and macrophage differentiation. The mouse model of osteosarcoma was established to evaluate the effects of exosomes on lung metastasis invivo. MG63 exosomes were successfully isolated and verified to be phagocytized by macrophages through fluorescence confocal microscopy. The results revealed that osteosarcoma cells could induce M2 type differentiation of macrophages largely through Tim-3 mediated by exosomes, which in turn could promote the migration, invasion, epithelial-mesenchymal transition (EMT), and lung metastasis of osteosarcoma cells through the secretion of cytokines including IL-10, TGF-β, and VEGF. Our results demonstrated that osteosarcoma-derived exosomes induced M2 polarization of macrophages and promoted the invasion and metastasis of tumors through Tim-3; besides, the study also suggests a novel therapeutic target for future studies.

A new certified reference material for size and shape analysis of nanorods using electron microscopy

A new certified reference material (CRM) for size and shape analysis of elongated nanoparticles has been developed by the European Commission’s Joint Research Centre. The CRM consists of titanium dioxide nanorods dispersed in 1-butanol, was coded ERM-FD103 and has been certified for different electron microscopy–based operationally defined measurands such as the modal and median values of the particle number-weighted distributions of the minimum and maximum Feret diameter, the maximum inscribed circle diameter, the area-equivalent circular diameter and the aspect ratio. The nanorods have nominal dimensions of 15 nm in width and 55 nm in length. Homogeneity and stability measurements were performed using transmission electron microscopy. The relative standard uncertainty for homogeneity ranged from 0.3 to 1.7%. No significant instability was detected for a shelf life of 18 months and a storage temperature of 18 °C. The certified values have been determined from the results of an interlaboratory comparison in which qualified expert laboratories participated with scanning and transmission electron microscopy. The certified values are traceable to the unit of length in the International System of Units, the metre, and the relative expanded uncertainties (confidence level of approximately 95%) range from 4 to 6%. These properties allow the CRM to be used for quality assurance and calibration of electron microscopy methods for nanoparticle size and shape analysis in ranges relevant for the implementation of EU legislation related to nanomaterials. The presented study discusses the purpose and results of the different steps that were followed to turn an industrially relevant raw titanium dioxide nanorod material into a fit-for-purpose CRM.Graphical abstract

Aggregation of Nanochemical Microcrystals in Urine Promotes the Formation of Urinary Calculi

With the increasing incidence and recurrence rate of urinary calculi, urinary calculi have become a serious health risk, and the research on urinary calculi has become the focus of public attention. At present, the research results on the formation mechanism of urinary calculi are not ideal, and there is no unified conclusion. In order to further study the influencing factors of the formation of urinary calculi and provide new ideas for the prevention and clinical treatment of urinary calculi, the influence of agglomeration of nanochemical microcrystals in urine on urinary calculi was studied in this paper. In this study, fresh morning urine was collected from 10 urological stone patients and 10 healthy controls without urological stone in the urology department of a hospital. After processing the experimental specimens, we first use flame atomic absorption spectrometry and alcian blue colorimetric method to detect the content of Ca2+ and citrate in the urine and then use the nanoparticle size analyzer to detect the microcrystals in the urine. Diameter, distribution, degree of aggregation and potential, and finally HRTEM observation to observe the morphology, chemical composition, and element composition of the nanocrystals. The results showed that the content of Ca2+ and lemon hydrochloric acid in the urine of the experimental group was lower than that of the control group. The particle size of the nanocrystals increased with the increase in the pore size of the membrane. The average particle size of the experimental group increased gradually from 163 ± 31 nm to 3219 ± 863 nm, while the average particle size of the control group increased from 183 ± 65 nm to 997 ± 522 nm. The mean value of the potential decreased with the increase in the pore size of the filter membrane. The change amplitude of the experimental group was 6.57 mV, while the change amplitude of the control group was only 1.75 mV. In the composition of nanocrystals, element O accounts for the most, accounting for 42.54% of all elements. This indicates that the aggregation of nanocrystals in urine will lead to the rapid increase in the size of nanocrystals, which will eventually lead to the formation of stones.

Carbene modification and reversible crosslinking of silver nanoparticles for controlled antibacterial activity

Silver nanoparticles (Ag NPs) system capable of exhibiting different particle size at different temperature was developed, which depended on the extent of Diels–Alder (DA) reaction of bismaleimide with furan. Thus, Ag NPs were functionalized on the surface by a furyl-substituted carbene through an insertion reaction. Subsequent reversible DA crosslinking achieved a controlled aggregation with different particle size, which gives a series of different antibacterial activity. These Ag NPs were characterized by Scanning Electron Microscopy (SEM), Transmission Electron Microscopy (TEM), X-ray Photoelectron Spectroscopy (XPS), and Nanoparticle Size Analyzer. The aggregation of the Ag NPs could be reliably adjusted by varying the temperature of DA/reverse-DA reaction. The antibacterial activity was assessed using the inhibition zone method against Escherichia coli (E. coli) and Staphylococcus aureus (S. aureus), which decreased first and then increased in agreement with the size evolution of Ag NPs. This approach opens a new horizon for the carbene chemistry to modify silver nanoparticles with variable size and give controlled antibacterial activity.

Synthesis and characterization of elution behavior of nonspherical gold nanoparticles in asymmetrical flow field-flow fractionation (AsFlFFF)

Asymmetrical flow FFF (AsFlFFF) is a member of field-flow fractionation (FFF) and can provide the separation of particles with size from nano to microscale based on their hydrodynamic diameters with smaller particles being eluted earlier than larger ones. For spheres, if the AsFlFFF conditions are well optimized, the FFF theory allows prediction of the elution time for a given diameter. Herein, we aim to use the AsFlFFF channel to compare the elution behavior of the gold nanoparticles with three different morphologies and give a comprehensive depiction for the mechanism of their separation in AsFlFFF. Furthermore, the particles size obtained from AsFlFFF was compared with that obtained from other techniques such as transmission electron microscopy (TEM), and dynamic light scattering. In this study, gold nanospheres (GNS), gold nanotriangles (GNT), and gold nanorods (GNR) were synthesized. TEM data stated that the mean particle diameter and the edge length of GNS and GNT were 51 and 35 nm, respectively, and the length of GNR was 47 nm. Although, the diameter of GNS is close to the length of GNR, the elution time of GNS (4.45 min) was much longer than that of the GNR (3.70 min) at the same AsFlFFF conditions. Also, the elution time of GNT was longer than that of GNR, even though it has smaller size than GNR. This might be attributed to GNR reaching an equilibrium position that is farther away from the accumulation wall of the channel than GNS, resulting in earlier elution than GNS. The GNT particles are rather similar in shape to spheres, and may behave more closely to the spheres than GNR. It seem that AsFlFFF could be an analytical technique for particle size analysis and separation of nanoparticles of different shapes.

Robust Nanoparticle Morphology and Size Analysis by Atomic Force Microscopy for Standardization.

Because of the complexity of nanomedicines, analysis of their morphology and size has attracted considerable attention both from researchers and regulatory agencies. The atomic force microscope (AFM) has emerged as a powerful tool because it can provide detailed morphological characteristics of nanoparticles both in the air and in aqueous medium. However, to our knowledge, AFM methods for nanomedicines have yet to be standardized or be listed in any pharmacopeias. To assess the applicability of standardization of AFM, in this study, we aimed to identify robust conditions for assessing the morphology and size of nanoparticles based on a polystyrene nanoparticle certified reference material standard. The spring constant of the cantilever did not affect the size of the nanoparticles but needed to be optimized depending on the measurement conditions. The size analysis method of the obtained images affected the results of the analyzed size values. The results analyzed by cross-sectional line profiling were independent of the measurement conditions and gave similar results to those from dynamic light scattering. It was indicated that approximately 100 particles are required for a representative measurement. Under the optimized conditions, there were no significant inter-instrument differences in the analyzed size values of polystyrene nanoparticles both in air and under aqueous conditions.

Energy release prediction and structure characterization of nano aluminum powder in situ coated by polyethylene glycol

In order to solve decreasing of reactivity of nano aluminum powder due to the alumina shell on the surface, used polyethylene glycol (PEG) as a coating material to obtain in situ PEG on nano aluminum particles with electrical explosion wires method. Based on the minimum free energy principle and BKW equation, the combustion and explosion performance of the coated sample is estimated. SEM and TEM to observe sample’s morphology and then used dynamic light scattering (DLS) nano-particle size analyzer to characterize sample’s particle size distribution. The chemical states of surface elements were analyzed by X-ray photoelectron spectroscopy. The thermal behavior of three samples were characterized by simultaneous thermal analyzer. The combustion heat, pressure-time curve, active Al content and vacuum stability was measured according to national standards. The results show that the coated sample was nearly sphere and particles were deduced multi-core structure. The active Al content reached 71.17% which is 12.53% higher than raw nano-Al particles. It was proved that PEG relieves oxidation of nano-Al, and the coating is stable. The coated samples can release energy more rapidly compared to micro-Al. The PVA in situ coated nano-Al particles has high active Al content and reactivity. Its application in energetic materials has good prospects.

Quantitative Analysis of Nanorod Aggregation and Morphology from Scanning Electron Micrographs Using SEMseg.

General methods to achieve better physical insight about nanoparticle aggregation and assembly are needed because of the potential role of aggregation in a wide range of materials, environmental, and biological outcomes. Scanning electron microscopy (SEM) is fast and affordable compared to transmission electron microscopy, but SEM micrographs lack contrast and resolution due to lower beam energy, topographic contrast, edge effects, and charging. We present a new segmentation algorithm called SEMseg that is robust to the challenges inherent in SEM micrograph analysis and demonstrate its utility for analyzing gold (Au) nanorod aggregates. SEMseg not only supports nanoparticle size analysis for dispersed nanoparticles, but also discriminates between nanoparticles within an aggregate. We compare our algorithm to those incorporated into the commonly used software ImageJ and demonstrate improved segmentation of aggregate structures. New physical insight about aggregation is demonstrated by the introduction of an order parameter describing side-by-side structure in nanoparticle aggregates. We also present the segmentation and fitting algorithms included in SEMseg within a user-friendly graphical user interface. The resulting code is provided with an open-source interface to provide quantitative image processing tools for researchers to characterize both dispersed nanoparticles and nanoparticle assemblies in SEM micrographs with high throughput.

Design and preparation of UV-curable waterborne polyurethane based on novel fluorinated chain extender

A series of UV-curable waterborne fluorinated polyurethane (UV-WFPU) were prepared successfully based on novel fluorinated side chain extender (F-TMP). The structure of F-TMP and particle size of UV-WFPU dispersions, contact angle (CA) and surface free energy, morphology, and damping property of UV-WFPU films were characterized through Fourier transform infrared spectroscopy, nanoparticle size analysis, contact angle test, scanning electron microscope and dynamic mechanical analysis (DMA), respectively. The results indicated that UV-WFPU dispersions had a particle size between 49.01 and 61.52 nm. The latex particle size and tan δ value of UV-WFPU films increased with the increase in F-TMP contents. The studies of surface properties confirmed that UV-WFPU films based on F-TMP had outstanding hydrophobicity properties. The highest CA of water and lowest surface free energy of UV-WFPU films reached 96.2° and 21.17 mJ/m2, respectively. Meanwhile, the DMA results showed UV-WFPU films possessed great damping property which had the broad temperature range enhanced by F-TMP, with a maximum value at 190.4 °C. The results of mechanical properties showed that the addition of fluorine increased in the tensile strength of the film. And these films have potential application values in the technical fields of damping, anti-corrosion and dust prevention.

OPTIMIZATION AND CHARACTERIZATION OF CHITOSAN BASED NANOCARRIER FOR THE APPLICATION OF CANCER DRUG DELIVERY

Nowadays, occurrence of cancer is rapidly increasing due to many risk factors. Currently, cancers are treated by using conventional drug delivery systems which have many limitations. Therefore, there is a need of suitable drug delivery system to treat the cancer with high therapeutic rate. With the advancement of nanotechnology, chitosan based nanocarrier system was proposed in this work to target the cancer cells with improved therapeutic effect. Therefore chitosan nanoparticles were synthesized and it was stabilized with PEG polymers. Before stabilization, concentration of chitosan was optimized by varying the concentration from 0.2% to 2% and the optimized concentration was found to be 1% by using UV Vis spectroscopy. Concentration of PEG polymers was also optimized by varying the concentration from 0.5% to 1.5%; the stability was analyzed for the duration of 15 days by using UV Vis spectroscopy and the best suitable concentration was determined to be 1%. Further, synthesized chitosan nanoparticles and PEGylated chitosan nanoparticles from optimized conditions were characterized by FTIR, DLS- particle size & Zeta potential to study its nature of functional group, size range, average particle size, surface charge and stability. FTIR spectrum of Chitosan nanoparticles showed the presence of hydroxyl, amine, carboxyl & alkyl groups and amide linkages whereas chitosan nanoparticles with PEG molecules showed the presence of hydroxyl, carboxyl & alkyl groups and amide linkages. Particle size analysis of chitosan nanoparticles and PEGylated chitosan nanoparticles was compared and the average particle size was determined to be 3.7 nm and 329.3 nm. Zeta potential analysis confirmed the surface charge of the chitosan nanoparticles was positive. It was highly stable after coating with PEG molecules and the zeta potential was found to be +38.4. Therefore, chitosan (1%) nanoparticles coated with PEG molecules (1%) will be a suitable system for the development of drug nanocarrier for the treatment of cancer.[1-5].

Preliminaries Methods for Detecting Urine Crystalline by Nanoparticle Size Analyzer

Urine crystals can be found in healthy urine and unhealthy urine (urolithiasis). Size analysis, in both with the nanoparticle size analyzer (PSA) is very useful for distinguishing urine crystallites under 1000 nm. The choice of methods and materials that are appropriate at the preparation stage before measurement will determine the accuracy of the data. The purpose of this study was to establish the right methods and materials for detecting crystals by PSA. PSA was used to compare intensity-autocorrelation curves (mean diameter) and polydispersity index of techniques and materials reviewed. Those: solution concentration; protein-coagulating; distilled water volume; micropore diameter; centrifugation value; and measurement angle. The best processing methods for urine crystallites detection was found. Antiseptics and protein-coagulation with NaN3 (2%) and formaldehyde (2.5%) were added to the urine, respectively. Urine was diluted with 50% ml distilled water then filtered through a 3 µm paper filter to remove the macromolecule. The supernatant was obtained by centrifuging the filtrate at 4000 rpm for 15 minutes. The angle (90°) applied to the measurement with Rayleigh scattering. These processing methods can remove biological cells and macromolecules in the urine. This preparation stage in the next research was applied to detect various types of urine crystals.

The emergence of chirality in cyanuric acid conglomerates by Viedma ripening: Surface characterization, chirality assessment and applications in chromatography

ABSTRACT In this paper, an attempt was made to obtain chiral conglomerates of cyanuric acid (CA) on the surfaces of different adsorbents, under similar to Viedma ripening conditions. To estimate CA conglomerate size, nanoparticle size analysis was performed. To characterize CA surface properties, scanning electron microscopy, nitrogen adsorption-desorption at 77 K, benzene and water adsorption were applied. The chiral recognition capability of CA was determined by enantiomer adsorption by CA-modified adsorbents from n-hexane solutions with polarimetric control and by analysis of enantiomer adsorption isotherms from the gas phase. Both methods showed the capability of CA regarding chiral recognition.

Microbial synthesis of CuNPs using Brevundimonas diminuta strain and its antibacterial activity

Green synthesis of nanoparticles is an emerging nanoparticle synthesis method due to its simplicity and non-toxicity. In the present study, we report the ability of Brevundimonas diminuta strains obtained from mining soil to synthesize copper nanoparticles (CuNPs). These strains were isolated from mining soil, identified and characterised. A bacterial enzyme, which is a characteristic for this species, was isolated, centrifuged and the resultant supernatant solution was used for nanoparticle synthesis from CuCl2. UV-visible spectrophotometer was used to assess the formation of nanoparticles. The size of the nanoparticles was verified using X-ray powder diffraction (XRD) and nanoparticle size analyser. Fourier-transform infrared spectroscopy (FTIR) was used to characterise the chemical nature of the reducing and capping agents present on the nanoparticles. Additionally, the effect of pH, time and concentration of CuCl2 on the CuNPs formation was also investigated. The synthesised nanoparticles showed anti-bacterial activity. The favourable synthesis of stabilised CuNPs demonstrates the relevancy of the isolated Brevundimonas diminuta strain for its bulk synthesis.

Banana leaves mediated bio-synthesis of silver nanoparticles

Silver (Ag) ions are successfully reduced to stable silver nanoparticles (AgNPs) using banana leaves. Conversion of Ag ions to AgNPs has been confirmed by UV-VIS analysis. The result of change on independent variables, i.e. temperature and strength of reducing agent on absorbance of solution and optimization of parameters has been done using response surface methodology (RSM) as per central composite design (CCD). The type of chemical group present on the nanoparticles is studied using fourier-transform infrared spectroscopy (FT-IR). Estimation of the size of particles has been done using transmission electron microscopy (TEM) and nanoparticle size analyzer. The crystallinity of the nanoparticles formed has been confirmed using XRD. Energy dispersive X-ray analysis (EDX) data is used to confirm the nanometal present.

The optical nanosizer - quantitative size and shape analysis of individual nanoparticles by high-throughput widefield extinction microscopy.

Nanoparticles are widely utilised for a range of applications, from catalysis to medicine, requiring accurate knowledge of their size and shape. Current techniques for particle characterisation are either not very accurate or time consuming and expensive. Here we demonstrate a rapid and quantitative method for particle analysis based on measuring the polarisation-resolved optical extinction cross-section of hundreds of individual nanoparticles using wide-field microscopy, and determining the particle size and shape from the optical properties. We show measurements on three samples consisting of nominally spherical gold nanoparticles of 20 nm and 30 nm diameter, and gold nanorods of 30 nm length and 10 nm diameter. Nanoparticle sizes and shapes in three dimensions are deduced from the measured optical cross-sections at different wavelengths and light polarisation, by solving the inverse problem, using an ellipsoid model of the particle polarisability in the dipole limit. The sensitivity of the method depends on the experimental noise and the choice of wavelengths. We show an uncertainty down to about 1 nm in mean diameter, and 10% in aspect ratio when using two or three color channels, for a noise of about 50 nm2 in the measured cross-section. The results are in good agreement with transmission electron microscopy, both 2D projection and tomography, of the same sample batches. Owing to its combination of experimental simplicity, ease of access to statistics over many particles, accuracy, and geometrical particle characterisation in 3D, this "optical nanosizer" method has the potential to become the technique of choice for quality control in next-generation particle manufacturing.

Size analysis of large-sized gold nanoparticles using single particle ICP-mass spectrometry

The analytical size range of nanoparticles are expanded toward a larger region using polyatomic ions.

Use of flow field-flow fractionation and single particle inductively coupled plasma mass spectrometry for size determination of selenium nanoparticles in a mixture.

Various analytical techniques have been used for size analysis of selenium nanoparticles (SeNPs). These include flow field-flow fractionation (FlFFF), single particle inductively coupled plasma mass spectrometry (SP-ICP-MS), dynamic light scattering (DLS) and transmission electron microscopy (TEM). For hydrodynamic diameter estimation, the FlFFF technique was used and the results were compared with those analyzed by DLS. For core diameter estimation, the results obtained from SP-ICP-MS were compared with those from TEM. Two types of FlFFF channel were employed, i.e., symmetrical FlFFF (Sy-FlFFF) and asymmetrical FlFFF (Asy-FlFFF). Considering the use of FlFFF, optimization was performed on a Sy-FlFFF channel to select the most appropriate carrier liquid and membrane in order to minimize problems due to particle membrane interaction. The use of FL-70 and 10 kDa RC provided an acceptable compromise peak quality and size accuracy for all samples of SeNPs which were coated by proteins (positively charged SeNPs) and sodium dodecyl sulfate (negatively charged SeNPs). FlFFF always yielded the lower estimate of the hydrodynamic size than DLS as a reference method. The results obtained by SP-ICP-MS were consistent with the TEM method for the core diameter estimation. The results from FlFFF and the DLS reference method were significantly different as confirmed by paired t-test analysis, while the results provided by SP-ICP-MS and the TEM reference method were not significantly different. Furthermore, consecutive size analysis by SP-ICP-MS for the fractions collected from FlFFF was proposed for sizing of SeNP mixtures. The combined technique helps to improve the size analysis in the complex samples and shows more advantages than using only SP-ICP-MS.

Influence of UV radiation on TiO2 nanoparticles antibacterial behaviour

Purpose: The influence of UV radiation on the antibacterial properties of titanium oxide nanoparticles was examined using yeast Saccharomyces cerevisiae strain for this purpose. Design/methodology/approach: Nanopowders were made with sol-gel method. Surface morphology studies of the obtained materials were made using Zeiss's Supra 35 scanning electron microscope. In order to confirm the chemical composition of observed nanopowders, qualitative tests were performed by means of spectroscopy of scattered X-ray energy using the Energy Dispersive Spectrometer (EDS). The DLS (Dynamic Light Scattering) method was used to analyse the particle size distribution using the AntonPaar Litesizer 500 nanoparticle size analyser. Changes in particle size distribution at elevated temperatures were also observed. The antibacterial properties of titanium oxide nanoparticles were examined by subjecting the yeast sample to irradiation with an UV lamp. Findings: Samples containing yeast Saccharomyces cerevisiae were irradiated with and without the addition of TiO2 nanoparticles. A faster decrease in the colony count was observed compared to irradiated exposures without the addition of a suspension. Practical implications: Presented materials can be used in the production of antibacterial coatings for surfaces occurring in public spaces such as schools, hospitals, public toilets for the simple and effective elimination of bacteria and fungi as a result of exposures. Originality/value: The antibacterial properties of titanium oxide nanoparticles under UV radiation were confirmed.

Effect of Nano Charcoal Ash Coconut Shell in Bitumen as Alternative Binder

The effect of Nano charcoal ash (NCA) from coconut shell on the physical and chemical properties of bitumen as alternative binder was evaluated in this study. Six different Nano grades of charcoal ash were examined. The charcoal ash ground for the optimum grinding time had a median particle size of 148 nm. NCA dosage of 30% by weight of binder was used throughout the experiments. Nanoparticle size analysis and X-ray fluorescence were performed to determine the size and chemical properties of material. Dynamic shear rheometer, penetration, softening point, and penetration index were used to characterize the physical properties of NCA. Thirty hours of grinding time produced the optimum NCA, which could enhance the binder performance. Test results indicated that adding NCA from coconut shell to bitumen improved the binder stiffness up to 47% and significantly increased the softening point up to 12% compared with virgin binder.

Serum Exosomal Long Noncoding RNA pcsk2-2:1 As A Potential Novel Diagnostic Biomarker For Gastric Cancer.

PurposeExosome-shuttled bioactive long non-coding RNA, as novel non-invasive biomarkers for cancer diagnosis, has received increasing attention. Here, we aimed to investigate the expression of serum exosomal long non-coding RNA pcsk2-2:1 (Exo-Lnc RNApcsk2-2:1) in patients of gastric cancer and evaluate its diagnostic value as a marker.Patients and methodsExosomes were isolated from serum sample of gastric cancer using HiPure Exosomekits and identified via transmission electron microscopy, Western blotting, and nanoparticle tracking analysis. The total exosomal RNA was extracted and reverse transcribed to cDNA. The expression of Exo-Lnc RNA PCSK2-2:1 was detected in serum exosomes of 29 healthy people and 63 gastric cancer patients by real-time quantitative reverse transcription PCR (qRT-PCR), and the relationship between the expression level of Exo-Lnc RNA PCSK2-2:1 and clinicopathological parameters of patients was analyzed. Finally, a receiver operating characteristic curve was used to evaluate the clinical value of Exo-Lnc RNA PCSK2-2:1 as an auxiliary diagnostic marker for gastric cancer.ResultsTransmission electron microscopy, nanoparticle size analysis, and Western blotting showed successful separation of serum exosomes. qRT-PCR results revealed that compared with the healthy control, Lnc RNA PCSK2-2:1 expression level in serum exosomes of gastric cancer patients was significantly downregulated (p=0.006). Moreover, the expression level of Exo-Lnc RNA PCSK2-2:1 was correlated with tumor size (p=0.0441), tumor stage (p=0.0061), and venous invasion (p=0.0367). The area under the curve of Exo-Lnc RNA PCSK2-2:1 was 0.896. At the optimal cut-off value, the diagnostic sensitivity and specificity were 84% and 86.5%, respectively.ConclusionOur data indicate that Exo-Lnc RNA PCSK2-2:1 may perform a vital role in the progression of gastric cancer and can be used as a potential marker for the diagnosis of gastric cancer.