Early detection enables improved prognosis for
prostate cancer (PCa). A promising target for imaging and
therapy of PCa is the prostate-specific membrane
antigen (PSMA), which exhibits both expression within the epithelium of PCa cells, and becomes internalized upon
ligand binding. Here we report the synthesis of a PSMA-targeted bionized nanoferrite (BNF) nanoparticle and its
biological evaluation in an experimental model of PCa. The BNF nanoparticle formulation exhibits properties conducive to targeted imaging such as stealth, prolonged circulation time and enhanced clearance from non-target sites. Optical imaging of the targeted BNF in vivo indicates preferential accumulation in PSMA+
tumors 4 h post-injection, suggesting target specificity. On the other hand, non-targeted nanoparticles exhibit lower uptake with similar accumulation in both PSMA+ and PSMA-
tumors indicating
tumor access without preferential accumulation. Imaging with single photon emission computed tomography (SPECT) and biodistribution studies of a modified construct indicate highest
tumor accumulation at 48 h post-injection [4.3 ± 0.4 percentage injected dose per gram of tissue (%ID g(-1))], with
tumor/blood and
tumor/muscle ratios of 7.5 ± 2.4 and 11.6 ± 1.2 %ID g(-1), respectively. Ex vivo fluorescence microscopy,
Prussian blue staining, immunohistochemistry and biodistribution studies confirm enhanced nanoparticle uptake in PSMA+
tumors compared to those not expressing PSMA. The BNF nano-formulation described is promising for PSMA-targeted imaging applications in vivo.