Papers by Keyword: Estradiol

Abstract: Extensive research is currently focused on finding alternative treatment for bone regeneration, due to the complexity and risks associated with existing procedures. One such alternative under investigation is the utilization of biodegradable nanofiber membranes, fabricated using an electrospinning method. In this study, polycaprolactone (PCL) was used as the main matrix to form electrospun membranes at different electrospinning parameters with the incorporation of estradiol to address bone regeneration capability. The effects of estradiol incorporation within the PCL membranes while determining the appropriate electrospinning parameters through morphological, chemical functionalities and wettability analyses were investigated. The inclusion of estradiol into the PCL matrix has reduced the nanofiber diameter and improved the wettability properties of the membranes. The alterations of electrospinning voltage and flow rate also impacted on the reduction of fiber diameter and wettability, which highlights the membrane’s potential for further cell attachment and bone regeneration.

Abstract: A new fluorescence immunoassay with high sensitivity, time-saving, good precision and reliablility was proposed for the determination of estradiol (E₂) in human urine. The complex of FITC-labeled anti-E₂ antibody was produced and regarded as a probe in this system. Ninety-six microplate was coated with ovalbumin conjugated E₂ antigen as solid phase for the immunoassay. The method parameters affecting the determination, such as the concentration of immunoreagents, pH, and other relevant variable conditions upon the immunoassay were studied and optimized systematically. Under the optimal experimental conditions, it was found that the proposed method exhibited high performance with the detection limit of 9.2 pg/mL, and the linear range of determination of 0.01-1000 ng/mL. The recoveries were 93.58-105.82% with the relative standard deviations (RSD) 5.52-7.09%. The proposed method has been used for the determination of E₂ in human urine with satisfactory results, and may be expected to find wide application in other environmental samples.

Abstract: An electrochemical sensor for estradiol was prepared by a molecularly imprinted polymer (MIP) film and its recognition properties for estradiol were investigated. The polypyrrole (PPy) film was prepared by electropolymerizing pyrrole on gold nanoparticles (Au NPs) and graphene (Gs) modified glassy carbon (GC) electrode. The electrochemical response of 17β-Estradiol (17β-E2) at the imprinted PPy-Gs-Au/GC electrode was investigated by cyclic voltammetry. The results indicated that the imprinted PPy-Gs-Au/GC electrode can effectively improve the electrochemical signal of 17β-E2 and eliminate interferences of other interfering substances. The results showed that a wide detection linear range (3.0 × 10^-9 1.0 × 10^-6 mol L^-1) for the determination of 17β-E2 with the low detection limit of 1.0 × 10^-9 mol L^-1 (S/N = 3) was obtained. The proposed sensor exhibited fast balance response time of 10 min, which is propitious to rapid detect 17β-E2 in real samples. The merits of the imprinted electrode suggested an attractive and broadly applicable way for developing the chemical sensor used for the estrogen detection.

Abstract: The adult male Rana nigromaculata were exposed to different doses of cadmium for 30d, serum concentrations of the steroid hormones, testosterone and estradiol were examined. Chronic exposure to cadmium caused significant changes both at the testosterone and estradiol levels. Exposure to cadmium resulted in lesser serum testosterone concentrations and more estradiol in 0.05 and 0.1 ppm. Although not statistically significant, frogs exposed to 0.2 ppm had smaller drop in testosterone and significant more estradiol. The results suggest that cadmium exhibited the non-monotonic dose-response relationship with the serum hormone concentrations, testosterone and estradiol.

Abstract: This paper reports an indirect competitive enzyme-linked immunosorbent assay (icELISA) using polyclonal antibody (pAb) for estradiol (E2) residues. After derivation, E2 haptens were conjugated to bovine serum albumin (BSA) and ovalbumin (OVA) through 1-Ethyl-3-(3-dimethylaminopropy) carbodiimide (EDC) method, and New Zealand white rabbits were immunized to produce anti-E2 pAb. The conjugation ratio of E2-BSA was proved to be 18.6:1 by an UV absorbance method. Based on the square matrix titration, an icELISA standard curve was developed. The dynamic range was from 0.16 to 128 ng/mL, with LOD and IC50 value of 0.08 ng/mL and 3.76 ng/mL, respectively. Except for a little cross-reactivity (16.2%) to estrone, this assay showed negligible cross-reactivity to other analogues tested. The results suggest that the produced anti-E2 pAb could be used to develop an icELISA method for the determination of E2 residues in animal-originally products.

Abstract: This paper presents an indirect competitive enzyme-linked immunosorbent assay (icELISA) using anti-mouse polyclonal antibody for rapid, sensitive analysis of 17-beta-estradiol (E2) residue. After derivation with succinic anhydride, E2 was coupled to bovine serum albumin (BSA) and ovalbumin (OVA) through carbodiimide active ester (EDC) method, and the conjugation ratio of E2-BSA was 18.6:1. Using mouse anti-E2 polyclonal antibody, an icELISA standard curve was established. The optimal concentrations of the coated E2-OVA and anti-E2 pAb were 2 μg/mL, and 1:32 000 dilutions, respectively, by the checkerboard titration. This method was sensitive and had a linear range from 0.16 to 128 ng/mL, with IC50 and LOD values of 3.76 ng/mL and 0.08 ng/mL. Therefore, the established icELISA provides a useful screening method for quantitative or qualitative detection of E2 residue in tissues or liquids.

Abstract: This study investigated the effects of exogenous estradiol on sex reversal in the Asian swamp eel (Monopterus albus) by evaluating the estradiol (E2) and testosterone (T) concentrations, gonadosomatic index (GSI), hepaticosomatic index (HSI) and the sex ratio. Fish (9.60 ± 0.92 g average initial weight; n = 3 per group) were fed with six different diets containing 0 (control), 20, 40, 60, 80 or 100 mg kg-1 dietary estradiol contents to apparent satiation for 15 months. Serum E2 and T concentrations were determined by radioimmunoassay. Levels of E2, GSI and HSI significantly increased while T concentrations and survival rates decreased as the exogenous estradiol levels were raised. Sex ratios did not differ significantly among all exogenous estradiol treatments, and there were no significant differences between the control group and the 20 mg kg-1 treatment group. Therefore, exogenous estradiol can maintain the female activity and delay sex reversal in M. albus. This study provides important information for successful reproductive management and may be exploited for the aquaculture of this species.