PEGylated palladium doped ceria oxide nanoparticles (Pd-dop-CeO2-PEG NPs) for inhibition of bacterial pathogens and human lung cancer cell proliferation

Abstract

Antibacterial and anticancer activities of metallic nanoparticles are limited due to their instability and agglomeration. Therefore, we hypothesize that the coating of biocompatible polyethylene glycol (PEG) improves stability, prevents agglomeration, and enhance the prolongs blood circulation. Hence, this work reports the characterization, anticancer and antibacterial activities of Pd-dop-CeO2-PEG synthesized by Trichoderma extract (FE-En). The reduction of broad-spectrum intensity at 420 nm indicated the successful synthesis of Pd (2+) to Pd (0) NPs. The TEM results revealed that doping of CeO2 and PEG conjugation did not affect the morphology and dispersion of Pd NPs, Pd-dop-CeO2, and Pd-dop-CeO2-PEG. All three nanoparticles were polydispersed and spherical in shape. The sizes were 8.01 ± 2.46 nm for PdNPs, 9.02 ± 3.15 nm for Pd-dop-CeO2, and 12.95 ± 3.41 nm for Pd-dop-CeO2-PEG. The zeta potential was −29.9 ± 0.89 mV for Pd NPs, −38.9 ± 0.15 mV for Pd–CeO2 and - 42.2 ± 0.74 mV for Pd-dop-CeO2-PEG. FTIR results revealed the involvement of –OH and the amide group of FE-En in the synthesis of Pd (2+) ions to Pd (0) NPs. XRD analysis confirmed the crystalline structure of Pd NPs, Pd-dop- CeO2, and Pd-dop-CeO2-PEG. The Pd-dop-CeO2-PEG NPs were biocompatible with chick embryos and NIH3T3 cells. However, these NPs exhibited strong cytotoxicity to A549 cells with an IC50 of 81.25 ± 1.21 μg/mL for Pd-dop-CeO2-PEG, 118.75 ± 0.89 μg/mL for Pd-dop-CeO2, and 231.25 ± 2.08 μg/mL for PdNPs. Further, fluorescent staining results confirmed that the Pd-dop-CeO2-PEG induced cell death in A549 cells through cellular damage by oxidative stress. Also, Pd-dop-CeO2-PEG exhibited higher antibacterial activity against bacterial pathogens. Overall, these results confirmed the successful development of Pd-dop-CeO2-PEG as a promising anticancer and antibacterial agents.