Toxicological Assessment of Nanomaterials in Biological Systems

Nanomaterials, defined by at least one dimension below 100 nm, exhibit unique physicochemical properties that underpin advances in medicine, electronics, energy and environmental remediation. Their high surface‐area‐to‐volume ratio, tunable surface chemistry and quantum effects, however, raise concerns over unintended biological interactions. Toxicological assessment in biological systems employs a tiered approach: detailed physicochemical characterisation of size, shape, charge and aggregation state; in vitro screening of key endpoints such as membrane integrity, mitochondrial function, oxidative stress and genotoxicity; and in vivo evaluation of organ‐specific responses including pulmonary inflammation, hepatic clearance and neurotoxicity. Mechanistic insights have been gained through reactive oxygen species (ROS) assays, inflammasome activation studies and apoptotic pathway analyses. Adverse outcome pathway frameworks increasingly guide the identification of molecular initiating events and subsequent key events that culminate in tissue injury. Challenges persist in establishing standardised dose metrics, extrapolating high‐dose results to realistic exposures and accounting for nano–bio corona formation. Emerging high‐throughput platforms, advanced imaging techniques and organ‐on‐chip models are improving predictive capacity. Such integrated strategies are critical to the safe design of next‐generation nanomaterials and to the development of regulatory guidelines that address occupational, clinical and environmental health risks on a global scale.

Research from Nature Portfolio

Investigations into the byproducts of polymer–nanoclay composites have demonstrated that combustion residues may pose pulmonary hazards at elevated exposures. In a foundational study, polylactic acid reinforced with organomodified montmorillonite was incinerated to simulate waste‐to‐energy processes, and the resulting particles were applied to human lung epithelial cells. Only at high doses did these byproducts reduce viability, alter cytoskeletal architecture and induce morphological changes, suggesting a threshold below which inhalation risk is low. The degree of nanoclay dispersion within the polymer matrix was found to influence degradation behaviour and cellular reactivity. These findings underscore the importance of end‐of‐life pathways in life‐cycle assessments and the need for safety protocols addressing combustion‐derived nanoparticles.

Toxicological Assessment of Nanomaterials in Biological Systems publication trend

The graph below shows the total number of articles in toxicological assessment of nanomaterials in biological systems across all publications each year (not limited to Nature Index journals).

Technical terms

Cytotoxicity: The capacity of a substance to cause cellular damage or death.

Genotoxicity: The ability of an agent to damage genetic information, leading to mutations or chromosomal alterations.

Reactive oxygen species (ROS): Chemically reactive molecules containing oxygen that can induce oxidative damage to lipids, proteins and DNA.

Inflammasome: A multiprotein complex that activates inflammatory caspases and promotes release of cytokines such as IL-1β.

Adverse outcome pathway (AOP): A conceptual framework linking a molecular initiating event through a series of key biological events to an adverse health outcome.

References

1. In vitro inflammation and toxicity assessment of pre- and post-incinerated organomodified nanoclays to macrophages using high-throughput screening approaches. Particle and Fibre Toxicology (2024).
2. Incineration of Nanoclay Composites Leads to Byproducts with Reduced Cellular Reactivity. Scientific Reports (2018).
3. Mechanistic study of silica nanoparticles on the size-dependent retinal toxicity in vitro and in vivo. Journal of Nanobiotechnology (2022).
4. Pro-inflammatory response and genotoxicity caused by clay and graphene nanomaterials in A549 and THP-1 cells. Mutation Research/Genetic Toxicology and Environmental Mutagenesis (2021).