ABSTRACT
Objective To establish the time-resolved fluoroimmunoassay(TRFIA)of CA199 based on Mag-netic Microspheres(Nano-TRFIA).Methods Based on a sandwich-type immunoassay format,analytes in sam-ples were captured by magnetic particles coated with anti-CA199 antibody B1 and"sandwiched"by anti-CA199 antibody B7 labeled with europium chelates.A total of 90 serum samples were analysed by this new method. Results The sensitivity was 0.2 U/mL,the intra.and inter.assay CV of the Nano-TRFIA were 4.84% and 8.32% respectively,and the average recovery rate was 97.91%.The cross-reacting rates with alpha fetopro-tein and CA125 were negligible.The labeled B1 with Magnetic Microspheres was at least stable for three months at 4 ℃.Serum samples from patients and healthy blood donors were analyzed,the linear correlation of TRFIA and ECLIA measurements was positive(Y = 0.969 8X+ 4.015 3).As the gold standard of ECLIA, Nano-TRFIA had two false positive.Conclusion The newly developed Nano-TRFIA based on Magnetic Mi-crospheres technique was highly sensitive,stable and specific in the immuno-determination of serum CA199. The results showed that the methods of Nano-TRFIA based on Magnetic Microspheres could be used for the clinic.
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Objective To prepare an immobilized acetylcholinesterase (AChE) microreactor and establish a rapid screening method for Chinese materia medica (CMM) acetylcholinesterase inhibitors (AChEIs). Methods A novel immobilized AchE microreactor was prepared by crosslinking with glutaraldehyde, using aminated magnetic microspheres as carrier. The characterizations were conducted by physicochemical properties and chromatographic performance. The immobilized AChE reactor was used to screen AChEIs from the Huperzia Serratum extracts. Results In the enzyme reaction system, the optimum substrate concentration was 50 μmol/L, and the incubation time was 5 min, respectively. IR characterization, specificity verification, enzyme kinetics, and stability study results all demonstrated the effectiveness of the enzyme reactor. The CMM AChEI, huperzine A, was obtained from the screening of H. Serratum extracts. Conclusion A high throughput screening method for AChEIs is established in this paper, which will be further applied and popularized.
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Objective To develop europium (Ⅲ) [Eu (Ⅲ)] chelated microparticles for homogeneous immunoassay.Methods Anti-human PCT antibodies were labeled with Eu (Ⅲ) chelated nanoscale microparticles as the detection antibody,and another anti-human PCT antibody was labeled with biotin as the solid-phase antibody.Magnetic microspheres labeled with streptavidin were used to separate the complexes of Eu-IgM-PCT-IgM-Biotin.Results In the homogeneous immunoassay,the standard curve fit was not linear.The quadratic curve was Y =19170.12 + 75493.74X-26.00X2(r =0.9986).According to the standard curve,the limit of detection for PCT was 0.04 ng/ml.Conclusion The homogeneous immunoassay which uses Eu (Ⅲ) chelated microparticles is highly sensitive for detection of PCT recombinant antigens and may serve as a promising method to measure serum PCT levels in the future.
ABSTRACT
Azathioprine loaded gelatin microspheres were formulated to control/target drug release in an arthritic joint by magnetic force or intra-articular injection. Glutaraldehyde cross linked microspheres were characterized for drug loading, entrapment efficiency, gas chromatography, magnetite content, particle size, scanning electron microscopy (SEM), Fourier-Infrared spectroscopy (FT-IR), differential scanning calorimetry (DSC) and in vitro release studies. The gelatin microspheres loaded with azathioprine showed 17% of drug loading with 82% of entrapment efficiency. Gelatin magnetic microspheres showed 13% of loading with 87% of entrapment efficiency. Gas chromatography confirms absence of residual glutaraldehyde in the microspheres. The magnetite content of the azathioprine loaded gelatin magnetic microsphere was 25.7% w/w. The average particle sizes of gelatin nonmagnetic and magnetic microspheres were 41 and 54 μm, respectively. SEM confirms the spherical nature of the microspheres. FT-IR revealed the absence of drug polymer interaction, and DSC suggested amorphous nature of entrapped drug in the microspheres. The formulated microspheres could release the drug over a period of 48 h.