Assessment of Genotoxicity of Silica Nanoparticles using in vitro and in vivo Studies: A Comprehensive ReviewAssessment of Genotoxicity of Silica Nanoparticles using in vitro and in vivo Studies: A Comprehensive Review

Silica nanoparticles (SiNPs) are integral to advancements in nanotechnology, finding extensive use in biomedical applications, consumer products, and industrial processes due to their tunable size, surface chemistry, and stability. However, their increasing prevalence has prompted significant concern regarding their potential adverse effects on human health, particularly their capacity to cause damage to genetic material, known as genotoxicity. This comprehensive review synthesizes and critically analyzes the current body of evidence on the genotoxic effects of SiNPs, drawing from both in vitro studies on various human and animal cell lines and in vivo studies conducted in animal models. The collective data indicate that SiNPs can indeed exhibit genotoxic properties, manifesting as DNA strand breaks, chromosomal abnormalities, and the formation of micronuclei. A predominant mechanism underlying this damage is the induction of oxidative stress, where SiNPs disrupt the cellular redox balance, leading to an overproduction of reactive oxygen species (ROS) that attack DNA. The review further explores how critical physicochemical parameters—such as particle size, surface charge, porosity, and functionalization—profoundly influence their genotoxic potential. These factors dictate cellular uptake, biodistribution, and subsequent biological interactions, making them crucial for safety-by-design approaches. While evidence points to genuine genotoxic hazards, inconsistencies in the literature highlight the need for standardized testing protocols and more nuanced studies that account for the complex interplay between nanoparticle properties and biological systems to enable accurate human health risk assessment.