Prostate stem cell antigen antibody-conjugated multiwalled carbon nanotubes for targeted ultrasound imaging and drug delivery.

Multiwalled carbon nanotubes (MWCNTs) are cut short and grafted with polyethylenimine (PEI) for further covalent conjugation to fluorescein isothiocyanate (FITC) and prostate stem cell antigen (PSCA) monoclonal antibody (mAb). The in vitro and in vivo toxicity data reveal that the as-prepared CNT-PEI(FITC)-mAb has good biocompatibility. Combined flow cytometry and confocal luminescence imaging experiments confirm that the CNT-PEI(FITC)-mAb can specifically target the cancer cells which overexpress PSCA. The results of in vitro and in vivo ultrasound (US) imaging indicate that CNT-PEI(FITC)-mAb has great potential to be used as a targeted US contrast agent. The in vivo anti-cancer efficacy testing using PC-3 tumor-bearing mice as animal models demonstrates that CNT-PEI(FITC)-mAb can targetedly deliver drug to the tumors and suppress tumor growth. Findings from this study suggest that the CNT-PEI(FITC)-mAb could be used as a multifunctional platform for simultaneous US imaging and drug delivery applications.