Surface modification of gold nanoparticles by cetirizine through surface plasmon resonance and preliminary study of the in vitro cellular cytotoxicity

In this study, gold nanoparticles are synthesized through a conventional redox reaction in water and characterized by means of TEM, DLS, XRD and UVvisible. The average diameter of gold nanoparticles is attained as 18 nm. Then, cetirizine drug is loaded on the as-prepared gold nanoparticles in an aqueous colloidal solution. This investigation shows that the peak of plasmon resonance is sensitive to the concentration of drug, therefore a tentative description is disclosed for this purpose. In addition, a green light source is adopted with the wavelength of plasmon peak of gold nanoparticles to excite the surface plasmons and induce release of the drug molecules. Then, the release profile is studied by UVvisible spectroscopy. It is found that the peak of surface plasmons shows a distinct blue shift, dependent upon the time of light irradiation. Plotting numerical data to the experimental curves for the absorption peaks gives interesting information on the loading/release behavior of cetirizine on the gold nanoparticles. The experimental data were fitted well with an exponential fucnction and we found that similar to 63% of the drug was released into the solution after about 7 min radiation. These results clearly show that the emitting green light can release the drug molecules, as can be detected by UVvisible absorption experiment. Outputs of this study offer a new insight on the investigation of drug delivery by using excitation of surface plasmon resonance from gold nanoparticles. Finally, the performed cellular cytoxicity and inhibitory dose IC50 of Au@cetirizine nanoparticles on nasopharyngeal carcinoms cell line (C6661) showed that this nanoparticle has an acceptable cytotoxicity toward the examined cell line and a decrease in the MTT signal was attained compared to the untreated cells. (C) 2021 Elsevier B.V. All rights reserved.