Lung Models to Evaluate Silver Nanoparticles’ Toxicity and Their Impact on Human Health

Abstract

Nanomaterials (NMs) solve specific problems with remarkable results in several industrial and scientific areas. Among NMs, silver nanoparticles (AgNPs) have been extensively employed as drug carriers, medical diagnostics, energy harvesting devices, sensors, lubricants, and bioremediation. Notably, they have shown excellent antimicrobial, anticancer, and antiviral properties in the biomedical field. The literature analysis shows a selective cytotoxic effect on cancer cells compared to healthy cells, making its potential application in cancer treatment evident, increasing the need to study the potential risk of their use to environmental and human health. A large battery of toxicity models, both in vitro and in vivo, have been established to predict the harmful effects of incorporating AgNPs in these numerous areas or those produced due to involuntary exposure. However, these models often report contradictory results due to their lack of standardization, generating controversy and slowing the advances in nanotoxicology research, fundamentally by generalizing the biological response produced by the AgNP formulations. This review summarizes the last ten years’ reports concerning AgNPs’ toxicity in cellular respiratory system models (e.g., mono-culture models, co-cultures, 3D cultures, ex vivo and in vivo). In turn, more complex cellular models represent in a better way the physical and chemical barriers of the body; however, results should be used carefully so as not to be misleading. The main objective of this work is to highlight current models with the highest physiological relevance, identifying the opportunity areas of lung nanotoxicology and contributing to the establishment and strengthening of specific regulations regarding health and the environment.

Advanced Respiratory Models for Hazard Assessment of Nanomaterials—Performance of Mono-, Co- and Tricultures

“…In the coculture model, around 3 µM and 15 µM Ag for the lower and higher concentration, respectively, was measured in the basolateral medium after exposure, and it is unknown if this was in form of Ag NMs or dissolved species. Reduced viability and increased DNA damage have previously been reported after exposure to Ag NMs in standard submerged cell cultures [ 83 , 84 , 85 , 86 ] at concentrations in the same range as the dissolved Ag we detected. The permeation of Ag was lower than that of fluorescein in the cocultures of A549 and EA.hy926 cells, which was expected as fluorescein is a water-soluble molecule.…”

Ag2O Nanoparticles as a Candidate for Antimicrobial Compounds of the New Generation

“…The ways to increase the cytotoxicity of Ag NPs against cancer and decrease against normal cells have been researched [152]. An interesting approach is using different coating agents; for example, Ag NP cytotoxicity increases in range "PVP > citrate > plant extracts > without coating", but in the case of PVP and citrate, increased predominantly anticancer activity [153].…”

Activities against Lung Cancer of Biosynthesized Silver Nanoparticles: A Review

“…However, adverse events such as anorexia, diarrhea, fatigue, and hypertension have been also documented [212]. As an alternative, multiple models have been developed to validate the anticancer activities of AgNPs; for example, lung monocultures, lung co-cultures, lung 3D cultures, and ex vivo and in vivo models [213].…”