Development of Protein Capped Nano Gold for NIR Photothermal and Molecular Imaging Applications for Diagnosis of Cancer Cells: In Vitro Studies

The current work demonstrated an in vitro model of diastase capped gold nanoparticles (Au NPs) and nanoplates (Au NPts) as unique contrast agents for molecular imaging and photothermal cancer therapy, respectively. The Au NPs/Au NPts were fabricated and conjugated with monoclonal antibodies of anti-epidermal growth factor receptor (anti-EGFR). Anti-EGFR-AuNPs bioconjugate was studied for molecular imaging allowing to interact with the nasopharyngeal carcinoma (CNE2 cells). Confocal immunofluorescence microscopic results revealed the increased scattering and reflectance properties of CNE2 cells after attachment and localization of Anti-EGFR-AuNPs bioconjugate on the cell surface, consequently providing the good optical contrast for the cancer cell imaging. On the other hand, Anti-EGFR-Au NPts were studied for photothermal applications using two malignant oral epithelial cell lines (HSC 3 and HOC 313 clone 8) and a nonmalignant epithelial cell line (HaCat), which revealed that the malignant cells require almost half of the laser energy to be photothermally eliminated after exposure to continuous red laser at 800 nm when compared with the nonmalignant cells. Further, the present approach may have potential for development of NPs for selective photothermal therapy and a successful diagnostics of cancer cell for bioimaging applications.