Palladium Nanoparticles: Toxicological Effects and Potential Implications for Occupational Risk Assessment

Abstract

The increasing technological applications of palladium nanoparticles (Pd-NPs) and their consequent enhancing release into the community and occupational environments, have raised public health concerns regarding possible adverse effects for exposed subjects, and particularly for workers chronically and highly exposed to these materials, whose toxico-kinetic and dynamic behavior remains to be fully understood. Therefore, this review aimed to critically analyze literature data to achieve a more comprehensive knowledge on the toxicological profile of Pd-NPs. Results from available studies demonstrated the potential for these chemicals to affect the ecosystem function, to exert cytotoxic and pro-inflammatory effects in vitro as well as to induce early alterations in different target organs in in vivo models. However, our revision pointed out the need for future studies aimed to clarify the role of the NP physico-chemical properties in determining their toxicological behavior, as well as the importance to carry out investigations focused on environmental and biological monitoring to verify and validate experimental biomarkers of exposure and early effect in real exposure contexts. Overall, this may be helpful to support the definition of suitable strategies for the assessment, communication and management of Pd-NP occupational risks to protect the health and safety of workers.

Comparison of the Wild-Type Obligate Methylotrophic Bacterium Methylophilus quaylei and its Isogenic Streptomycin-Resistant Mutant via Metal Nanoparticle Generation

“…Taking into account the pleiotropic nature of the streptomycinresistant mutation in M. quaylei SM R bacteria, it can be assumed that the actively synthesized exopolysaccharides of M. quaylei MT T very quickly come into contact with palladium ions Pd and therefore selectively block the formation of Pd°NPs. This statement is supported by data on the high reactivity of Pd 2+ cations towards biopolymers [45][46][47]. Thus, from the two isogenic cultures of methylotrophic bacteria, the ability to generate Pd°NPs manifests only in the streptomycinresistant M. quaylei SM R .…”

An Up-To-Date Review on Biomedical Applications of Palladium Nanoparticles

“…Concerning in vivo results, the target effect of PdNPs is on the immune, renal, and endocrine systems [101]. Iavicoli et al studied the potential immunotoxic impact of immunostimulatory and immunosuppressive effects of PdNPs on Wistar rats [102].…”

“…Recently, some possible toxic effects of PdNPs on living systems and their surrounding environment have been reported [101]. However, an understanding of the toxicity of PdNPs is still incomplete and needs more intensive investigations.…”

Intracellular Antioxidant Activity of Biocompatible Citrate-Capped Palladium Nanozymes

“…In this regard, the presence of synthesis by-products, endotoxins, contaminations, and surface functionalities has a strong influence and could be the reason of the observed toxicity in many reports [28]. Therefore, the determination of the toxicological profile of the nanomaterial is still missing, even though it is crucial for the applications of Pd in the field of nanomedicine [29]. A clearer picture of the toxicological profile of PdNPs would promote the exploitation of their catalytic activities in the medical field for developing novel nanocatalysts or drug delivery nanosystems with therapeutic properties.…”