S. Ghosh, T.J. Webster
Kasetsart University,
Thailand
Keywords: platinum, palladium, bimetallic nanoparticles, anticancer, apoptosis, antioxidant
Summary:
As per the estimates of American Cancer Society, 1,918,030 new cancer cases are projected to occur in USA alone in 2022. Hence, the overall increase in cancer cases throughout the globe is alarming that warrants effective therapeutic strategy. Although, platinum based drugs like cisplatin, carboplatin, oxaliplatin, are used for treatment of cancer, they have potential side effects. Hence, the study aimed to develop a greet route for synthesizing platinum and palladium nanohybrids with promising anticancer activity.The Dioscorea bulbifera tuber extract (DBTE) was used for synthesis of platinum nanoparticles (PtNPs), palladium nanoparticles (PdNPs) and platinum-palladium nanoparticles (Pt-PdNPs). The nanoparticles were characterized employing various analytical techniques and evaluated for anticancer activity against HeLa cells. Phytochemical analysis of DBTE revealed high phenolic (0.53 ± 0.04 mg/mL), starch (1.08 ± 0.02 mg/mL), total reducing sugar (3.41 ± 0.15 mg/mL), diosgenin (0.026 ± 0.006 mg/mL), ascorbic acid (0.17 ± 0.005 mg/mL) and citric acid (0.28 ± 0.01 mg/mL) content. High-resolution transmission electron microscopy revealed monodis-persed PtNPs of size 2–5 nm, while PdNPs and Pt–PdNPs between 10 and 25 nm. Energy dispersive spectroscopy analysis confirmed 30.88%±1.73% elemental Pt and 68.96%±1.48% elemental Pd in the bimetallic nanoparticles. Fourier transform infrared spectra indicated strong peaks at 3,373 cm-1, attributed to hydroxyl group of polyphenolic compounds in DBTE that might play a key role in bioreduction in addition to the sharp peaks at 2,937, 1,647, 1,518, and 1,024 cm-1, associated with C–H stretching, N–H bending in primary amines, N–O stretching in nitro group, and C–C stretch, respectively. Anticancer activity against HeLa cells showed that Pt–PdNPs exhibited more pronounced cell death of 74.25% compared to individual PtNPs (12.6%) or PdNPs (33.15%). Further, Pt–PdNPs showed an enhanced scavenging activity against 2,2-diphenyl-1-picrylhydrazyl, superoxide, nitric oxide, and hydroxyl radicals. In view of the background, it can be concluded that DBTE mediated synthesis of PtNPs, PdNPs, and Pt-PdNPs is a rapid, efficient, environmentally benign route for developing novel anticancer nanomedicine.