Oxidative stress-induced neurotoxicity of quantum dots and influencing factors

Abstract

Quantum dots (QDs) have significant potential for treating and diagnosing CNS diseases. Meanwhile, the neurotoxicity of QDs has garnered attention. In this review, we focus on elucidating the mechanisms and consequences of CNS oxidative stress induced by QDs. First, we discussed the pathway of QDs transit into the brain. We then elucidate the relationship between QDs and oxidative stress from in vivo and in vitro studies. Furthermore, the main reasons and adverse outcomes of QDs leading to oxidative stress are discussed. In addition, the primary factors that may affect the neurotoxicity of QDs are analyzed. Finally, we propose potential strategies for mitigating QDs neurotoxicity and outline future perspectives for their development.

Graphical abstract

Executive summary

Pathways of quantum dots into the brain

• The blood–brain barrier is one of the main routes for quantum dots (QDs) to enter the CNS, and QDs with a particle size of only a few nanometers can easily cross the blood–brain barrier and enter brain tissue in a short time.

• QDs can also be transported to the brain via the olfactory nerve by inhalation.

QDs induce neurotoxicity through oxidative stress

• Cadmium-based QDs induce changes in oxidative stress levels and neurobehavior in experimental animals or model organisms. In in vitro studies, cadmium-based QDs produced abnormal increases in reactive oxygen species, microglial activation and neuronal damage.

• Noncadmium-based QDs also induce changes in the level of oxidative stress, but this change is twofold, with some QDs exhibiting toxicity and others exhibiting protective effects.

Mechanisms of oxidative damage to the CNS induced by QDs

• QDs entering the CNS cause an abnormal increase in ROS and exceed the body's ability to compensate, resulting in oxidative stress.

• QDs can lead to altered activity of antioxidant enzymes and increased consumption of antioxidants, ultimately causing oxidative damage.

• Accumulation of ROS and dysfunction of the antioxidant system ultimately cause damage to biomolecules, including lipid peroxidation, protein and DNA damage.

Factors influencing the neurotoxicity of QDs

• The chemical composition, particle size, surface functionalization, surface charge and protein corona of QDs affect the neurotoxicity of QDs to varying degrees. Modifying QDs to address these factors will help mitigate the neurotoxicity of QDs.

Keywords: :

• blood–brain barrier
• mechanism
• neurotoxicity
• oxidative stress
• quantum dots
• reactive oxygen species

Author contributions

Conception: Q Fang. Initial manuscript drafting: Q Fang. Review and final manuscript preparation: Q Fang and M Tang.

Financial disclosure

This work was supported by the National Natural Science Foundation of China (nos. 82173545, 21876026 and 31671034), the Natural Science Foundation of Jiangsu Province (no. BK20180371), the Postgraduate Research & Practice Innovation Program of Jiangsu Province (no. KYCX22_0300) and Fundamental Research Funds for the Central Universities (no. 2242023k30020). The authors have no other relevant affiliations or financial involvement with any organization or entity with a financial interest in or financial conflict with the subject matter or materials discussed in the manuscript apart from those disclosed.

Competing interests disclosure

The authors have no competing interests or relevant affiliations with any organization or entity with the subject matter or materials discussed in the manuscript. This includes employment, consultancies, honoraria, stock ownership or options, expert testimony, grants or patents received or pending, or royalties.

Writing disclosure

No writing assistance was utilized in the production of this manuscript.

Additional information

Funding

This work was supported by the National Natural Science Foundation of China (nos. 82173545, 21876026 and 31671034), the Natural Science Foundation of Jiangsu Province (no. BK20180371), the Postgraduate Research & Practice Innovation Program of Jiangsu Province (no. KYCX22_0300) and Fundamental Research Funds for the Central Universities (no. 2242023k30020). The authors have no other relevant affiliations or financial involvement with any organization or entity with a financial interest in or financial conflict with the subject matter or materials discussed in the manuscript apart from those disclosed.