Comparison of in vivo uptake of radioactive gold nanoparticles formulated using phytochemicals

Objectives Aim to evaluate ¹⁹⁸Au nanoparticles (AuNP) biodistribution and uptake in a human prostate model for treatment. Many phytochemicals are known to have anti-tumor properties but have short half-lives in vivo. We hypothesized that using these phytochemicals to formulate and coat AuNP would inhibit enzyme cleavage and enhance their anti-tumor properties. Initial evaluations were performed in SCID mice bearing PC3 tumors.

Methods : ¹⁹⁸AuNP were formulated with the following gum Arabic, epigalocatechin gallate (EGCg) pomegranate extract and mangiferin extract. The resultant nanoparticles were evaluated in normal mice and in human prostate bearing SCID mice. The tumor bearing mice were injected intratumorally with 3-5 uCi of ¹⁹⁸AuNP and euthanized at the following time points 30 min, 1,2,4 and 24 hr. Various organs were removed and counted along with standards to calculate the percent injected dose per organ and per gram.

Results All nanoparticles showed high retention in the tumor with the ¹⁹⁸AuNP formulated from mangiferin showing the highest retention 80.98 ± 13.39 %ID at 30 min and remaining steady out to 24 hr 79.82 ±10.55 % ID. The tumor uptake and retention was in the following order mangiferin> pomegranate (61.5 ± 26.4 %ID > EGCg 36.2 ± 12.5 %ID > gum Arabic 17.75.± 23.36 %ID.

Conclusions : ¹⁹⁸AuNP were stably formed using gum Arabic, EGCg, pomegranate extract and mangiferin. The ¹⁹⁸AuNp were shown to be retained in high yields in prostate tumors demonstrating their potential for ablation of prostate cancer.

Research Support This research supported by NSEI, MURR, Green Technology institute /MU. Al-Yasiri supported by the University of Baghdad and NSEI.