In-vitro prostate cancer biomarker detection by directed conjugation of anti-PSCA antibody to super paramagnetic iron oxide nanoparticless.

The main property of a successful conjugation of antibodies to nanoparticles is keeping the potency of antibody for binding the antigen， and an oriented conjugation can do that. Under such ground， this study was carried out to explore the efficiency of two conjugation methods in binding iron nanoparticles to an antibody produced against PSCA (prostate stem cell antigen) using in vitro labeling of PC3 cells. In this experimental study， we conjugated dextran-superparamagnetic iron oxide nanoparticles (dexSPIONs) to anti-PSCA antibody by two different methods， including targeting carbohydrate moieties in FC domain and the free amine group of amino acid side chains. Ultimately， Iron staining was done by anti-PSCA antibody-dexSPIONs in PC3 cells to detect antibody binding to the cells. A strong blue dye was induced by iron staining in conjugated dexSPIONs on the membrane of PC3 cells by the former method than the second one. Moreover， cells treated with 20 nm diameters of dexSPIONs showed higher resolution of blue color than those treated with 100 nm nanoparticles. This oriented conjugation method promoted the efficiency of targeting tumor antigens， and the presence of iron particles might enhance MRI image intensity in vivo by targeting PSCA-overexpressing cells in future studies.