Flower-like gold nanoparticles labeled and silver deposition rapid vertical flow technology for highly sensitive detection of Brucella antibodies

Lipopolysaccharides of Brucella suis S2 Impaired the Process of Decidualization in Early Pregnancy in Mice

Brucellosis is a notorious zoonotic disease caused by Brucella, which can lead to reproductive diseases in humans and animals, such as infertility and abortion. Lipopolysaccharides (LPS) are the main virulence factor of Brucella. LPS derived from Brucella are different and non-classical and are less toxic and less active than LPS isolated from E. coli. However, the effects and possible mechanisms of Brucella LPS-caused pregnancy loss remain to be revealed. In the present study, we investigated the effects of Brucella suis S2 LPS on early pregnancy loss in mice. The results indicated that embryo implantation failure was induced by Brucella LPS treatment in a dose-dependent manner. The injection of Brucella LPS mainly resulted in fibrinolysis in the decidual area of the uterus on the 6th day post coition (dpc), infiltration of large granular cells among the decidual cells near the embryo on the 8th dpc, a large number of gaps in the decidual area, and cell necrosis around the embryo. In addition, the expression of Cyclin D3 mRNA in the uterus on the 7th and 8th dpc and IGFBP-1 mRNA and the progesterone receptor in the uterus on the 6th and 7th dpc were also inhibited. Moreover, the expression of decidualization marker Cyclin D3 and decidualization prolactin-associated protein (dPRP) in endometrial stromal cells were also inhibited by Brucella LPS treatment in vitro. In summary, Brucella LPS affect the process of endometrial decidualization in mice by affecting the structure of the decidua and the expression of decidual marker factors in endometrial stromal cells.

Novel Vertical Flow Immunoassay with Au@PtNPs for Rapid, Ultrasensitive, and On-Site Diagnosis of Human Brucellosis

Brucellosis is an infectious zoonosis caused by Brucella with clinical symptoms of wavy fever, fatigue, and even invasion of tissues and organs in the whole body, posing a serious threat to public health around the world. Herein, a novel vertical flow immunoassay based on Au@Pt nanoparticles (Au@PtNPs-VFIA) was established for detection of Brucella IgG antibody in clinical serum samples. The testing card of Au@PtNPs-VFIA was manufactured by printing the purified Brucella LPS and goat antimouse IgG on the nitrocellulose membrane as the test-spot or control-spot, respectively. Au@PtNPs labeled with protein G (Au@PtNPs-prG) were concurrently employed as detection probes presenting visible spots and catalysts mimicking catalytic enzymes to catalyze the DAB substrate (H2O2 plus O-phenylenediamine) for deepening color development. The testing procedure of Au@PtNPs-VFIA takes 2-3 min, and the limit of detection (LOD) for Brucella antibody is 0.1 IU/mL, which is faster and more sensitive than that of Au@PtNP-based lateral flow immunoassay (Au@PtNPs-LFIA: 15 min and 1.56 IU/mL, respectively). By comparing with vertical flow immunoassay based on classic Au nanoparticles (AuNPs-VFIA), the Au@PtNPs-VFIA is 32 times or 16 times more sensitive with or without further development of DAB substrate catalysis. Au@PtNPs-VFIA did not react with the serum samples of Gram-negative bacterium infections but only weakly cross-reacted with diagnostic serum of Y. enterocolitica O9 infection. In detection of clinical samples, Au@PtNPs-VFIA was validated for possessing 98.33% sensitivity, 100% specificity, and 99.17% accuracy, which were comparable with or even better than those obtained by the Rose-Bengal plate agglutination test, serological agglutination test, AuNPs-VFIA, and Au@PtNPs-LFIA. Therefore, this newly developed Au@PtNPs-VFIA has potential for rapid, ultrasensitive, and on-site diagnosis of human Brucellosis in clinics.

Gold Nanoparticles Synthesized with Common Mullein (Verbascum thapsus) and Castor Bean (Ricinus communis) Ethanolic Extracts Displayed Antiproliferative Effects and induced Caspase 3 Activity in Human HT29 and SW480 Cancer Cells

Gold nanoparticles (AuNPs) are promising nanomaterials exhibiting anti-cancer effects. Green AuNPs synthesis using plant extracts can be used to achieve stable and beneficial nanoparticles due to their content of bioactive compounds. This research aimed to synthesize and evaluate the antiproliferative and caspase-3 activity induction of green AuNPs synthesized with common mullein (V. thapsus) flowers (AuNPsME) and castor bean (R. communis) leaves (AuNPsCE) ethanolic extracts in human HT29 and SW480 colorectal cancer cells. Their effect was compared with chemically synthesized AuNPs (AuNPsCS). The extracts mainly contained p-coumaric acid (71.88–79.93 µg/g), ferulic acid (19.07–310.71 µg/g), and rutin (8.14–13.31 µg/g). The obtained nanoparticles presented typical FT-IR bands confirming the inclusion of polyphenols from V. thapsus and R. communis and spherical/quasi-spherical morphologies with diameters in the 20.06–37.14 nm range. The nanoparticles (20–200 µg/mL) showed antiproliferative effects in both cell lines, with AuNPsCE being the most potent (IC50 HT29: 110.10 and IC50SW480: 64.57 µg/mL). The AuNPsCS showed the lowest intracellular reactive oxygen species (ROS) generation in SW480 cells. All treatments induced caspase 3/7 activity to a similar or greater extent than 30 mM H2O2-treated cells. Results indicated the suitability of V. thapsus and R. communis extracts to synthesize AuNPs, displaying a stronger antiproliferative effect than AuNPsCS.