Novel gadopentetic acid-doped silica nanoparticles conjugated with YPSMA-1 targeting prostate cancer for MR imaging: an in vitro study

The early diagnosis of prostate cancer (PCa) is particularly important for reducing its high mortality rate. With the development of molecular magnetic resonance imaging (MRI), early diagnosis via non-invasive imaging has become possible. In this study, gadopentetic acid (GA)-doped silica (Gd@SiO2) was first synthesized by a reverse microemulsion method, and amino and carboxyl groups were then successively introduced onto the surface of this Gd@SiO2. After these steps, a monoclonal antibody (YPSMA-1) to prostate-specific membrane antigen (PSMA) was conjugated with carboxyl-modified Gd@SiO2 (Gd@SiO2-COON) nanoparticles (NPs) by the carbodiimide method. Gd@SiO2-Ab NPs were thus obtained as specific MR contrast agents for PCa-targeted imaging. Transmission electron microscopy showed that the Gd@SiO2-Ab NPs exhibited a dispersed spherical morphology with a relatively uniform size distribution. The Gd@SiO2-Ab NPs showed high stability and high the longitudinal relaxation rate (r(1)). Cell targeting experiments in vitro demonstrated the high potential of the synthesized NPs to target PSMA receptor-positive PCa cells. In vitro cytotoxicity assays showed that the Gd@SiO2-Ab NPs exhibited good biological safety. These results suggest that the synthesized Gd@SiO2-Ab NPs have great potential as specific MR contrast agents for PSMA receptor-positive PCa cells. (C) 2018 Elsevier Inc. All rights reserved.