The Application Of Magnetic Particles In Drug Delivery And Immunoassay

Magnetic particles are composed of superparamagnetic nanoparticles and other materials such as organic or inorganic compound. They offer advantages in both magnetic separation and in the immobilization of bio-molecules, therefore, the magnetic particles have been widely used in target delivery, MRI, magnetic bio-separation and solid-phase assay etc, herein, the application of magnetic particles in drug delivery and the magnetic affinity immunoassay(MAIA) for anti-HCV antibody and IL-8 was studied separately.The rat liver cancer model was established and the magnetic chitosan nanoparticles was used as the carrier for loading doxonibicin (DOX), after injection magnetic particles coupled with doxonibicin and free doxonibicin (DOX) by 2 mg·kg^-1 iv. Dose., the concentration of doxonibicin in serum and the doxonibicin distribution in different tissue were determined. The result indicated that the magnetic particles could change the concentration of DOX in serum and tissues, prolonged the time of DOX in serum, enriched the medicinein in the target tissue, while reduce the medicinein in the healthy tissues.The GoldMag particles with assembled structure was used as the carrier in MAIA test, the recombined antigen of HCV was coated on the magnetic particles, and then to detect anti-HCV Ab in serum based on the indirect-ELISA, the sensitivity, reliability of this method was detected, and the method was also used to analyze the anti-HCV in serum samples of blood donors and some patients. The result showed that the method for detection anti-HCV antibody completely meets the demand of the clinical diagnosis.A rapid and sensitive immunoassay for quantitative determination of interleukin-8 (IL-8) was developed employing a couple of specific monoclonal antibodies, one of which was immobilized on GoldMag particle surface and the other labeled withhorseradish peroxidase (HRP). A calibration curve of IL-8 was established, the limit of detection, recovery, and the IL-8 concentration in normal and hepatic cellular cancer (HCC) patients were detected. This new method can enhance the sensitivity of detection and reduce the time of process compared with the conventional sandwich ELISAusing microplate as carrier.