Nanoparticles-induced brain injury: prevalence, mechanisms, and implications

Abstract

Nanotechnology has opened new frontiers in neuroscience and medicine, with nanoparticles (NPs) playing a pivotal role in enhancing drug delivery systems and diagnostic precision. Due to their high surface-to-volume ratio and adaptable surface chemistry, NPs can traverse the blood–brain barrier (BBB), offering novel therapeutic strategies for central nervous system (CNS) disorders. However, these same properties raise safety concerns, particularly regarding their accumulation in neural tissues and the potential to disrupt neural homeostasis. This review critically examines the neurotoxicity associated with exposure to metal-based and carbon-based nanoparticles. It explores the underlying mechanisms—including oxidative stress, mitochondrial dysfunction, inflammation, and activation of apoptosis pathways that contribute to neural injury. Furthermore, disruptions in cholinergic and purinergic signaling are highlighted as key contributors to cognitive decline and neurodegeneration induced by NPs. A comprehensive overview of nanoparticles classification, BBB permeability, and CNS interactions is provided, alongside discussion of emerging in vitro and in vivo models that facilitate translational research. The review emphasizes the urgent need to balance the therapeutic potential of NPs with a thorough understanding of their safety profiles. Advancing regulatory frameworks and designing biocompatible nanoparticles formulations will be essential steps toward minimizing neurotoxic risks while harnessing nanotechnology for neuromedical innovation.