Toxicity Alleviation of Carbon Dots from Roast Beef after the Formation of Protein Coronas with Human Serum Albumin

The unique properties of nanoparticles produced during food thermal processing have attracted considerable attention. In this study, the formation of protein coronas of fluorescent carbon dots (CDs) in roast beef with human serum albumin (HSA) and the corona effect on toxicity were reported. The CDs were roughly spherical with a size in the range of 1–5 nm, which were mainly composed of carbon (68.68%), nitrogen (10.6%), and oxygen (15.98%). The CDs could readily pass through the intestine wall due to their small size and good water solubility. There was an obvious interaction between HSA and CDs, suggesting that the CDs could form protein coronas. Thermodynamic analysis results of ΔH < 0 (−13.17 ± 3.74 kJ/mol) and ΔS > 0 ( 28.04 J/mol/K) indicated that the binding of HSA–CDs was due to electrostatic interactions or hydrophobic forces. The HSA–CD coronas were distributed in the lysosomes of the cells, alleviated swelling caused by the CDs, and inhibited the decrease of mitochondrial membrane potential caused by CDs. Furthermore, the protein coronas reduced cellular reactive oxygen species production and alleviated the consumption of glutathione by the CDs, thus protecting the cells from damage. This finding provided valuable information about protein coronas in ameliorating cytotoxicity.