Cancer antigen 125 assessment using carbon quantum dots for optical biosensing for the early diagnosis of ovarian cancer.

Fluorometric quantification of biological molecules is a key feature used in many biosensing studies. Fluorescence resonance energy transfer (FRET) using highly fluorescent quantum dots offers highly sensitive detection of the in-proximity wide variety of analyst molecules. In this contribution, we report the use of carbon quantum dots (CDs) for the ultrasensitive optical biosensing of cancer antigen 125 (CA-125) in the early malignant stage. This approach is based on monitoring the quenching of CDs luminescence at 535 nm by CA-125 after excitation at 425 nm and pH 10. The calibration of this method was performed in the concentration range of CA-125 from 0.01 to 129 U ml-1 (R 2 = 0.99) with a detection limit of 0.66 U ml-1, which matches remarkably with the standard chemiluminometric method in control and real patient samples. The sensing mechanism for cancer antigen 125 assessment was discussed on the basis of fluorescence quenching of CDs and time-resolved photoluminescence spectroscopy. The current method is easy, sensitive, cost-effective and provides a wide range of validity, which helps in overcoming the limitations of high cost and time consumption exhibited by many other traditional clinical assays for CA-125 quantification.

Highly ordered functionalized mesoporous silicate nanoparticles reinforced poly (lactic acid) gatekeeper surface for infection treatment.

The controlled release of a drug considers the key feature of the delivery carrier that enhances therapeutic efficacy. This study was aimed at design, synthesis of nano valve and capping systems onto caged functionalized mesoporous silica nanoparticles (SBA15) with nanoflowers polylactic acid (PLA-NF). Levofloxacin (LVX) as a specific model drug was encapsulated onto series; SBA15, SBA15@NH2, and SBA15@NH2/PLA. The examined nanocarriers released in a controlled fashion by external stimuli. The delivery vehicle based on PLA-NF coated SBA15@NH2, potent conjugated with LVX with experienced a high extent of trapping content with fast releasing by pH regulating mechanism. In vial LVX released profile and in vitro antifungal forceful of the selected microbes were detected. However, SBA15@NH2/PLA exhibited pore size, surface area and pore volume 5.4 nm, 163 and 0.011 respectively, but the significantly clear zone was obtained with Staphylococcus aureus ATCC 6538 (G+ve), Escherichia coli ATCC 25922 (G-ve), Candida albicans ATCC 10231 (yeast) and Aspergillus niger NRRL A-326 (fungus). Viability test avouch that rising functionality enhanced cytocompatibility and non-toxicity profile. Based on the aforementioned promising data, this type of nanocarriers offers when functionalized with targeting cells, the accessibility to deliver antibiotics onto nanosystem for increased potency against microbes and reduce side effects.

Urine test for HPV genotypes as a predictor of precancerous cervical lesions and for cervical cancer screening.

OBJECTIVE: To assess the sensitivity of a urine test for high-risk HPV DNA genotypes in the detection of high-grade squamous intra-epithelial lesion (HSIL) and its correlation with pathologic precancerous lesions. METHODS: The present prospective cross-sectional study included women referred to Kasr AlAiny Medical School, Cairo, Egypt, for cervical smear anomalies, a history of cervical smear anomalies, or for suspicious cervix between May 1, 2015, and April 30, 2017. Paired urine tests and cervical smears were performed. HPV DNA was detected in urine using polymerase chain reaction and cervical smears were performed with a cervical spatula and a cytobrush. Agreement between urine test results and pathology was examined. RESULTS: In total, 1375 women were included. Urine test for high-risk HPV DNA demonstrated 97.8% (95% confidence interval [CI] 92.1%-99.7%) sensitivity and 100% (95% CI 99.7%-100.0%) specificity for HSIL. Overall, 87 women had a positive urine test for high-risk HPV; of these, 82 (94.3%, 95% CI 87.1%-98.1%) had pathologic findings of cervical intra-epithelial neoplasia 2 or 3 (CIN2/3). Similarly, 89 women had HSIL cytology; again, 82 had CIN2/3 (92.1%; 95% CI, 84.3%-96.4%). CONCLUSION: There was good agreement between a positive urine test for high-risk HPV DNA genotypes and pathologic findings of CIN2/3.

Halogen bond triggered aggregation induced emission in an iodinated cyanine dye for ultra sensitive detection of Ag nanoparticles in tap water and agricultural wastewater.

Aggregation induced emission (AIE) has emerged as a powerful method for sensing applications. Based on AIE triggered by halogen bond (XB) formation, an ultrasensitive and selective sensor for picomolar detection of Ag nanoparticles (Ag NPs) is reported. The dye (CyI) has an iodine atom in its skeleton which functions as a halogen bond acceptor, and aggregates on the Ag NP plasmonic surfaces as a halogen bond donor or forms halogen bonds with the vacant π orbitals of silver ions (Ag+). Formation of XB leads to fluorescence enhancement, which forms the basis of the Ag NPs or Ag+ sensor. The sensor response is linearly dependent on the Ag NP concentration over the range 1.0-8.2 pM with an LOD of 6.21 pM (σ = 3), while for Ag+ it was linear over the 1.0-10 µM range (LOD = 2.36 µM). The sensor shows a remarkable sensitivity for Ag NPs (pM), compared to that for Ag+ (µM). The sensor did not show any interference from different metal ions with 10-fold higher concentrations. This result indicates that the proposed sensor is inexpensive, simple, sensitive, and selective for the detection of Ag NPs in both tap and wastewater samples.

Photo-induced interaction of thioglycolic acid (TGA)-capped CdTe quantum dots with cyanine dyes.

The photo-induced interaction of three different sizes of thioglycolic acid (TGA)-capped CdTe quantum dots (CdTe QDs) with two monomethine cyanine dyes belonging to the thiazole orange (TO) family has been studied. Positively charged cyanines interact with QDs surface which is negatively charged due to capping agent carboxylate ions. The energy transfer parameters including Stern-Volmer constant, Ksv, number of binding sites, n, quenching sphere radius, r, the critical energy transfer distance, R0, and energy transfer efficiencies, E have been calculated. The effect of structure and the number of aggregating molecules have been studied as a function of CdTe QDs particle size. Combining organic and inorganic semiconductors leads to increase of the effective absorption cross section of the QDs which can be utilized in novel nanoscale designs for light-emitting, photovoltaic and sensor applications. A synthesized triplet emission of the studied dyes was observed using CdTe QDs as donors and this is expected to play a potential role in molecular oxygen sensitization and in photodynamic therapy (PDT) applications.

Screening for Chlamydia trachomatis in Egyptian women with unexplained infertility, comparing real-time PCR techniques to standard serology tests: case control study.

BACKGROUND: To study the prevalence of Chlamydia infection in women with primary and secondary unexplained infertility using ELISA technique for antibody detection and real time, fully automated PCR for antigen detection and to explore its association with circulating antisperm antibodies (ASA). METHODS: A total of 50 women with unexplained infertility enrolled in this case control study and a control group of 44 infertile women with a known cause of infertility. Endocervical specimens were collected for Chlamydia antigen detection using PCR and serum samples for antibodies detection. Circulating anti-sperm antibodies were detected using sperm antibody Latex Agglutination tests. RESULTS: The overall prevalence of Chlamydial infection in unexplained infertility cases as detected by both ELISA and PCR was 40 % (20/50). The prevalence of current Chlamydial genital infection as detected by real-time PCR was only 6.0 % (3/50); two of which were also IgM positive. Prevalence of ASA was 6.0 % (3/50); all were sero-negative for anti-C.trachomatis IgM and were PCR negative. CONCLUSION: The incidence of Chlamydial infection in Egyptian patients with unexplained infertility is relatively high. In the setting of fertility investigations; screening for anti. C.trachomatis antibodies using ELISA, and treatment of positive cases should be considered. The presence of circulating ASA does not correlate with the presence of old or current Chlamydia infection in women with unexplained infertility.