Novel cytosensor for accurate detection of circulating tumor cells based on a dual-recognition strategy and BSA@Ag@Ir metallic-organic nanoclusters.

Herein, based on a dual-recognition strategy and BSA@Ag@Ir metallic-organic nanoclusters (BSA@Ag@Ir MONs), a highly specific and sensitive cytosensor was developed for detecting circulating tumor cells (CTCs). To amplify current signal, novel BSA@Ag@Ir MONs with outstanding catalytic activity and huge specific surface area were synthesized, and conjugated with hairpin DNA strands as signal probes. Orion carbon black 40 (Ocb40)//AuNPs were firstly used to modify electrode to increase its conductivity and surface area. Moreover, the dual recognition strategy based on DNA proximity effect was designed to improve the specificity of cytosensor. When two capture probes respectively bound to two adjacent membrane markers of target cells, the probes could form the associative toehold through the proximity effect to capture the signal probes. Only CTCs simultaneously expressing two membrane markers could be captured and generate current responses. The developed cytosensor could detect CTCs in the range of 3 - 3 × 106 cells mL-1 with a detection limit of 1 cell mL-1. Notably, the cytosensor could accurately identify CTCs even in whole blood. Therefore, this cytosensor has great potential for application in biological science, biomedical engineering and personalized medicine.

A dual recognition strategy for accurate detection of CTCs based on novel branched PtAuRh trimetallic nanospheres.

Accurate detection of circulating tumor cells (CTCs) has a pivotal role in the metastasis monitoring and prognosis of tumor. In this work, an ultrasensitive electrochemical cytosensor was developed based on excellent electrocatalytic materials and a dual recognition strategy. Herein, novel branched PtAuRh trimetallic nanospheres (b-PtAuRh TNS) were synthesized for the first time by a facile one-pot method, which had a huge specific surface area and outstanding catalytic activity. B-PtAuRh TNS linked with aptamers targeting mucin1 (MUC1) were served as signal tags to amplify the signal. As electrode modified material, the nanocomposites of Cabot carbon black (BP2000) and AuNPs were used to improve the electron transfer efficiency of electrode. In addition to using b-PtAuRh TNS labeled anti-MUC1 aptamers as signal probes, anti-EpCAM antibodies were worked as capture probes to achieve dual recognition of target cells. In other words, only cells expressing both MUC1 and EpCAM could produce electrochemical signal. The constructed cytosensor presented a wide linear range (5 - 1 × 106 cells mL-1) and a low detection limit (1 cell mL-1). It was worth noting that the proposed cytosensor could detect CTCs in clinical blood samples. To sum up, the developed cytosensor might become a promising detection platform for cancer diagnosis and tumor metastasis.

Factors affecting the success of fallopian tube recanalization in treatment of tubal obstructive infertility.

OBJECTIVE: To examine potential risk factors associated with the success rate following fallopian tube recanalization (FTR) in infertile women with obstruction of the proximal fallopian tube. METHODS: We retrospectively studied patients who underwent FTR for tubal obstructive infertility between January 2016 and December 2018 at the Third Affiliated Hospital of Guangzhou Medical University. FTR was performed using a catheter and guidewire system to clear tubal obstruction. Predictive factors potentially associated with the success rate were assessed by logistic regression. RESULTS: A total of 762 patients were included. Multivariable analysis showed that age (odds ratio [OR] = 2.38, 95% confidence interval [CI]: 1.24-4.58), infertility type (OR = 2.82, 95% CI: 1.36-6.21), history of ectopic pregnancy (OR = 7.87, 95% CI: 4.05-15.81), history of abdominal surgery (OR = 4.30, 95% CI: 2.22-8.60), history of artificial abortion curettage (OR = 4.08, 95% CI: 2.12-8.03), and duration of infertility (OR = 2.03, 95% CI: 1.06-3.85) were independently associated with postoperative tubal patency. CONCLUSIONS: Our findings suggest that risk factors, such as age ≥35 years, secondary infertility, duration of infertility ≥5 years, and histories of ectopic pregnancy, abdominal surgery, and artificial abortion curettage, affect the success rate of FTR. These factors may also predict surgical success in treating tubal obstructive infertility.

Ultrasensitive aptasensor for isolation and detection of circulating tumor cells based on CeO2@Ir nanorods and DNA walker.

Herein, based on dual signal amplification by CeO2@Ir nanorods (Ce@IrNRs) and enzyme-free DNA walker, a novel electrochemical aptasensor was developed for simultaneous isolation and detection of circulating tumor cells (CTCs). A membrane protein MUC1-targeting aptamer was used to specifically recognize and capture MCF-7 cells. Uracil DNA glycosylase could hydrolyze deoxyuracils of the aptamer to isolate the captured cells. Novel Ce@IrNRs with large surface area and high peroxidase activity were synthesized to amplify the signal, and the enzyme-free DNA walker was applied to release more signal probes combined with Ce@IrNRs. Furthermore, to reduce steric hindrance by cells, the signal probes rather than the target cells, were directly combined with the electrode. The aptasensor could detect CTCs in the range of 2 to 2 × 106 cells mL-1 with a limit of detection 1 cell mL-1. The developed aptasensor, which can simultaneously isolate and detect CTCs, has great application potential in the early monitoring of tumor metastasis and in individualized treatment.

Modified sandwich embolization technique for postpartum hemorrhage caused by uterine artery pseudoaneurysm: a case series.

PURPOSE: Uterine artery pseudoaneurysm (UAP) is rare but can cause life-threatening postpartum hemorrhage (PPH). To evaluate a novel sandwich embolization technique as a treatment for PPH caused by UAP. METHODS: This retrospective study included 10 patients with PPH caused by UAP who were treated using a modified sandwich embolization technique at the Radiology Department, Third Affiliated Hospital of Guangzhou Medical University between April 2009 and September 2018. Baseline clinical characteristics, intraoperative data (including treatment effectiveness) and postoperative data (including re-bleeding events and complications) were extracted from the medical records. RESULTS: Uterine arterial angiography showed cystic shadowing of the vascular wall during the arterial phase in all patients. Spraying of contrast agent into the pseudoaneurysm was observed for large UAPs, and the pseudoaneurysm disappeared in the venous phase. The pseudoaneurysm blood supply was from the uterine artery in 9 patients (90%) and the uterine, superior vesical, internal pudendal and nameless little arteries in 1 patient (10%). Bleeding symptoms were completely relieved in all patients after sandwich embolization. Eight patients experienced painful contractions in the perioperative period, but there were no other postoperative complications. During the 1-year postoperative follow-up, 9 patients (90%) had no re-bleeding symptoms/signs. One patient (10%), who had a pseudoaneurysm supplied by the uterine, superior vesical, internal pudendal and nameless little arteries, experienced re-bleeding 20 days after surgery and was treated by hysterectomy. CONCLUSION: Modified sandwich embolization is an effective treatment for PPH caused by UAP.

PdIrBP mesoporous nanospheres combined with superconductive carbon black for the electrochemical determination and collection of circulating tumor cells.

An integrated electrochemical immunoassay is described for the determination of circulating tumor cells (CTCs). For the first time, Ketjen black (KB), which is a superconductive carbon material, was incorporated with Au nanoparticles (AuNPs) and used to modify the surface of gold electrodes. A cocktail of anti-epithelial cell adhesion molecules (EpCAM) and anti-vimentin antibodies was chosen to capture the CTCs. Palladium-iridium-boron-phosphorus alloy-modified mesoporous nanospheres (PdIrBPMNS) served as a catalytic tag to amplify the current signal. Glycine-HCl (Gly-HCl) was used as an antibody eluent to release and collect the captured CTCs from the electrodes for further clinical research without compromising cell viability. The response of the method increased linearly from 10 to 1 × 106 cells mL-1 CTCs, while the detection limit was calculated to be as low as 2 cells mL-1. This method was successfully used to determine CTCs in spiked blood samples and demonstrated good recovery. Graphical abstractKetjen black/AuNPs was incorporated in the electrochemical platform to enhance the electron transfer ability of the electrode surface. PdIrBP mesoporous nanospheres were used to amplify DPV signal in this assay. The introduction of Gly-HCl realized nondestructive recovery of circulating tumor cells.

Docosahexaenoic acid inhibits bone remodeling and vessel formation in the osteochondral unit in a rat model.

OBJECTIVES: We aimed to determine whether bone remodeling and vessel formation in the osteochondral unit are suppressed by supplementing with docosahexaenoic acid in anterior cruciate ligament transection (ACLT)-induced rats. METHODS: Twelve-week-old male Sprague Dawley rats were randomized to sham-operated, ACLT-operated and treated with vehicle, or ACLT-operated and treated with DHA groups. Micro-architecture and vasculature in the tibial osteochondral unit were examined by micro-CT, as well as by histomorphometry. To evaluate the effects of DHA in vitro, we conducted functional and expressional assays in RAW264.7 cells and HUVECs. Finally, we used OARSI-modified Mankin criteria and histological analyses to assess the status of the cartilage layer. RESULTS: Microstructural parameters in the osteochondral unit showed that bone mass loss and angiogenesis were less in DHA-treated rats than in vehicle-treated rats. Immunofluorescence-positive cells labeled with TRAP, RANKL, CD31, and endomucin agents in the osteochondral unit of ACLT-operated rats were reduced in the DHA-treated group compared with the vehicle-treated group. Furthermore, the number of TRAP-stained cells, areas of bone resorption pits, and mRNA expression of TRAP, CTSK, MITF, and NFATC1 were reduced in RAW264.7 cells treated with RANKL + DHA compared with those treated with only RANKL. Tube formation, proliferation and migration of HUVECs, and VEGF-C mRNA and VEGFR2 protein expression were inhibited by DHA. The decrease in OARSI score, and MMP-13 and collagen X expression suggested that DHA attenuated cartilage degeneration. CONCLUSIONS: DHA has the ability to restrain bone remodeling and vessel formation in the osteochondral unit, which may contribute to protection of cartilage.

Colorimetric determination of BCR/ABL fusion genes using a nanocomposite consisting of Au@Pt nanoparticles covered with a PAMAM dendrimer and acting as a peroxidase mimic.

A colorimetric assay is described for the detection of BCR/ABL fusion genes. Polyamidoamine (PAMAM) dendrimers were placed on peroxidase (POx) mimicking Au@Pt nanoparticles to form a nanocomposite of type Au@Pt-PAMAM. Capture DNA probe is a designed nucleic acid strand that specifically binds target DNA to the surface of the electrode. The capture probe was attached to magnetic beads via biotin and avidin interaction. The hairpin structure of the capture probe can only be opened by the complementary BCR/ABL DNA. This results in a highly specific assay. The POx-mimicking property of the Au@Pt-PAMAM causes the formation of a blue dye by reaction of H2O2 and 3,3,3',3'-tetramethylbenzidine (TMB) which is measured by a microplate reader. Under optimum conditions, the absorbance increases linearly the 1 pM to 100 nM BCR/ABL concentration range, and the detection limit is as low as 190 fM. The method is highly selective and was successfully applied to the determination of fusion genes in spiked real samples. Conceivably, it possesses a large potential in clinical testing of patients suffering from chronic myeloid leukemia. Graphical abstract Au@PtNP, an efficient catalyst, is bound with polyamidoamine (PAMAM) dendrimer to amplify the colorimetric signal. With the introduction of streptavidin-magnetic beads to remove non-specific signals, a novel colorimetric sensor is constructed to detect BCR/ABL fusion genes.

A novel cytosensor based on Pt@Ag nanoflowers and AuNPs/Acetylene black for ultrasensitive and highly specific detection of Circulating Tumor Cells.

Circulating tumor cells (CTCs), as the cellular origin of metastasis, are cancer cells that break away from a primary tumor and circulate in the peripheral blood. And they provide a wealth of information about tumor phenotype. Here, this work reported a novel ultrasensitive immunoassay protocol for the detection of CTCs by using Pt@Ag nanoflowers (Pt@AgNFs) and AuNPs/Acetylene black (AuNPs/AB) nanomaterial. In the established approach, AuNPs/AB nanomaterial was used as substrate material to increase the specific surface area and enhance the conductivity of the gold electrode. Protein G was used for oriented immobilization of capture antibody, which strongly improved the capture efficiency of MCF-7 cells. The innovatively synthesized Pt@AgNFs by our group with high specific surface area and good biocompatibility were not only as the carriers of signal antibodies (Ab2) but also catalyzed the reduction of H2O2, which effectually amplified the current signal. A linear relationship between current signals and the concentrations of CTCs was obtained in the range from 20 to 1×106 cells mL-1 and the detection limit is as low as 3 cells mL-1 on condition of acceptable stability and reproducibility. Furthermore, the as-proposed cytosensor showed excellent performance in the detection of CTCs in human blood samples. These results suggest that the proposed cytosensor will be a promising application for accurately quantitative detection of CTCs.

Inhibition of YAP suppresses CML cell proliferation and enhances efficacy of imatinib in vitro and in vivo.

BACKGROUND: Yes-associated protein (YAP), an essential component of Hippo pathway, was identified as an oncoprotein which participated in the progression of various malignancies. However, its role in chronic myeloid leukemia (CML) remains to be further clarified. METHODS: The expression of YAP in CML cells was determined by western blotting. Next, the effects of YAP knockdown and YAP inhibitor on CML cells were evaluated by MTT assay, flow cytometry (FCM) and Wright's staining. Moreover, K562 induced mice model was employed to further investigate the role of YAP in vivo. RESULTS: YAP was overexpressed in CML cells. Knockdown of YAP by si-RNA or inhibition the function of YAP using verteporfin (VP) not only inhibited the proliferation, induced the apoptosis of CML cells but also reduced the expression of YAP target genes c-myc and survivin. Additionally, VP enhanced the efficacy of imatinib (IM) in vitro and suppressed leukemogenesis in vivo. CONCLUSION: Our results indicate that YAP may play an important role in the proliferation and leukemogenesis of CML cells. Genetic or pharmacological inhibition of YAP provides a novel treatment strategy for CML.

A novel label-free and reusable electrochemical cytosensor for highly sensitive detection and specific collection of CTCs.

Circulating tumor cells (CTCs) contain a great deal of information of tumor phenotype. Therefore, highly sensitive detection and specific enrichment of CTCs are of intense interest. Herein, a label-free electrochemical impedance spectroscopy cytosensor with effective surface recognition between specific epithelial cell adhesion molecules (EpCAM) over-expressed on the cell membrane and EpCAM aptamer was developed for the detection of CTCs. After immobilization of 6-mercapto-1-hexanol (MCH) onto the gold electrode, the capture probe can be directionally inserted in MCH interspaces, which can improve the sensitivity of the cytosensor. A wide detection range from 30 to 1×10(6)cellsmL(-1) with a detection limit as low as 10cellsmL(-1) is reached on the condition of acceptable stability and reproducibility. The cytosensor can easily distinguish CTCs from the real blood sample due to the specific combination of EpCAM and EpCAM aptamer. Furthermore, the cytosensor can be reused 8 times and enrich CTCs by Uracil DNA Excision Mix specific cleaving the deoxyuridines (dUs) of the aptamer. The collected CTCs can contribute to further study. Thus, we reported that this cytosensor is a promising technique for the early monitoring and therapy of cancer.

A universal probe design for colorimetric detection of single-nucleotide variation with visible readout and high specificity.

Single-nucleotide variation (SNV) is a crucial biomarker for drug resistance-related detection in cancer and bacterial infection. However, the unintended binding of DNA probes limits the specificity of SNV detection, and the need for redesigned sequences compromise the universality of SNV assay. Herein, we demonstrated a universal and low-cost assay for the colorimetric discrimination of drug-resistance related point mutation. By the use of a universal DNA probe and a split G-quadruplex, the signal could be recognized by naked eye at room temperature. The DNA probe was used as a signal reporter which not only improved the universality, but also enabled high specificity of probe hybridization. This assay was successfully applied in the detection of cancer-related SNV in the epidermal growth factor receptor (EGFR) gene, kirsten rat sarcoma viral oncogene homologue (KRAS), and tuberculosis drug-resistance related point mutation in RNA polymerase beta subunit gene (rpoB) with high specificity and visible readout. This method was simple, rapid, high-throughput and effective, which was suitable for point-of-care applications.

A novel platform for high sensitivity determination of PbP2a based on gold nanoparticles composited graphitized mesoporous carbon and doxorubicin loaded hollow gold nanospheres.

Gold nanoparticles composite graphitized mesoporous carbon nanoparticles (GMCs@AuNPs) biocomposite with the signal amplification capability was successfully synthesized for use in an immunoassay for penicillin binding protein 2 a (PbP2a). The polyamidoamine (PAMAM) dendrimers were first electrodeposited onto the Au electrode can greatly increase the amount of the captured antibodies. Protein A was used to properly orientate immobilized antibody against PbP2a, which strongly improved specificity of the antigen-antibody binding. Hollow gold nanospheres (HGNPs) as effective nanocarriers have been synthesized by sacrificial galvanic replacement of cobalt nanoparticles capable of encapsulating doxorubicin (Dox). The obtained HGNPs@Dox bionanocomposite was used for further loading of detection antibody (Ab2) to form the HGNPs@Dox@Ab2 bioconjugate. Then, the differential pulse voltammetric signals related to the concentration of PbP2a for Dox could be detected, and the immunosensor exhibited a detection limit as low as 0.65 pg mL(-1) (at an S/N ratio of 3). The proposed method with an excellent differentiation ability showed high sensitivity and specificity. The morphologies and electrochemistry properties of the composites were investigated by scanning electron microscopy, electrochemical characterization, UV-visible absorption spectroscopy, fluorescence spectrophotometer and Malvern laser particle size analyzer, respectively. In addition, the basic approach described here would be applicable towards developing biodetection assays against other important targets. Moreover, the bioconjugate of HGNPs@Dox is also a promising pattern to delivery Dox in vivo for anticancer therapy.