Redox Activity and Nano–Bio Interactions Determine the Skin Injury Potential of Co₃O₄-Based Metal Oxide Nanoparticles toward Zebrafish

Abstract

Redox-active metal oxide nanoparticles show varying oxidizing capacities and injury potentials toward biological systems. Here, two metal oxide libraries including transition-metal-doped Co 3 O 4 and PdO-Co 3 O 4 with strong chemical contacts were design-synthesized and used to investigate their biological injury potential and mechanisms using zebrafish as a model organism. Among different dopants, Cu significantly increased the oxidizing capacity of Co 3 O 4. An increased amount of PdO resulted in higher density of heterojunctions, which also led to higher oxidizing capacity. The oxidizing capacity of these nanoparticles was positively correlated with higher mortality of dechorionated embryos and severe larval skin injury upon exposure. Using transgenic zebrafish Tg(LysC:eGFP), we show in real time that the redox-active nanoparticles induced skin injury and activated the infiltration of immune cells. Such inflammatory response was confirmed by the increased mRNA expression level of Nrf 2a, HO-1, IL-1β, and IL-6 genes. Although the exposure to the nanoparticles alone was not lethal, the skin injury did lower the tolerance level against other environmental contaminants. More importantly, after withdrawing from the nanoparticle exposure, larvae with skin injury could recover within 24 h in uncontaminated medium, indicating such injury was transient and recoverable.

Disproportional surface segregation in ligand-free gold–silver alloy solid solution nanoparticles, and its implication for catalysis and biomedicine

“…In a more recent study, doped oxide nanoparticles were examined for catalytic features in in vivo skin lesion assays in zebrafish. ROS generation causing the observed cell damage was correlated with I) charge transfer through different oxidation states in the doped nanoparticles, II) charge transfer from the space charge layer to the electron sink in tightly coupled elements, and III) Ion release 2 . Next to these unintended use scenarios, nanoparticle-induced ROS is further discussed as one of the most critical pathways in the anti-tumor efficiency of sensitizers in irradiation therapy 3 .…”

“…ROS generation causing the observed cell damage was correlated with (I) charge transfer through different oxidation states in the doped nanoparticles, (II) charge transfer from the space charge layer to the electron sink in tightly coupled elements, and (III) ion release. 2 Next to these unintended use scenarios, nanoparticle-induced ROS is further discussed as one of the most critical pathways in the anti-tumor efficiency of sensitizers in irradiation therapy. 3 Here, a recent study suggested a correlation between therapy-enhancing effects of Pt and Au nanoparticles in proton therapy and catalytic surface reactions.…”

Where Is Nano Today and Where Is It Headed? A Review of Nanomedicine and the Dilemma of Nanotoxicology

“…For instance, an assessment of PLA nanoparticles’ safety using D. melanogaster revealed that the mechanisms behind near-lethal nanoparticle doses are related to oxidative stress and cell cycle arrest at G1 − and other aquatic models, such as Artemia salina , and Daphnia magna , appeared to be very useful to assess polymeric nanomaterials’ safety. Together, these in vivo alternative models are excellent tools for initial toxicological screening or complementary steps.…”

Magnetically propelled chained nanocomposites for biologically relevant media exploration

“…S2 (bottom panel), increasing as the viscosity of the medium considered increases. While in ultrapure water, the chains attain an average length of $5 lm and in the glycerol/water mixture is $12 lm, in the much more viscous cell tissue extract the average length is about [40][41][42][43][44][45][46][47][48][49][50] lm. In this regard, a high viscous medium helps the dipolar interactions between the nanocomposites to become stronger because it implies more interactions and collisions that cause them to undergo a diffusive motion which is much greater than the stan- dard Brownian motion [35].…”