Metallic Nanoparticles and Cosmetics: The Role of Mitochondria and Premature Aging.

The cosmetic industry has developed and commercialized numerous products using new technologies, making them increasingly appealing to the public. The use of metallic nanoparticles (MtNPs) as key ingredients in cosmetics has become more widespread due to their demonstrated benefits. However, the use of these products remains controversial, as some studies have shown that MtNPs can penetrate the deeper layers of the skin and disrupt homeostatic balance. It has also been demonstrated that the interaction between MtNPs and keratinocytes increases the generation of reactive oxygen species (ROS), which can lead to oxidative stress, a condition associated with premature aging. Mitochondria, as the main organelles responsible for energy production, also provide and maintain the regulatory mechanisms necessary for keratinocytes to sustain a strong protective barrier against environmental threats including MtNPs. To date, the relationship between redox imbalance, premature aging, and the central role of mitochondria remains under investigation due to the fact that mitochondrial metabolism, linked to increased oxidative stress, is associated with the development of various defense mechanisms, including antioxidant enzymes. In this review, we focus on the role of oxidative stress generated in mitochondria and the function of antioxidant enzymes in detoxifying metal ions from MtNPs contained in cosmetics. We examine their effects on keratinocytes and the potential for premature aging.