Hemocompatibility investigation and improvement of near- infrared persistent luminescent nanoparticle ZnGa2O4:Cr3+ by surface PEGylation

Although near-infrared persistent luminescent nanoparticles are widely used in optical imaging of tumors and grafted cells, there is no report on the behavior of chromium-doped zinc gallate (ZnGa2O4:Cr3+, ZGC) nanoparticles in contact with blood. In this work, monodisperse ZGC NPs with a size of about 10 nm usually used in bioimaging were synthesized by a hydrothermal method. We have evaluated the effect of ZGC NPs on blood in terms of hemolysis, and erythrocyte morphology, erythrocyte aggregation, coagulation, thrombosis and complement system activation. We improved ZGC NP blood compatibility by functionalizing them with hydrophilic polyethylene glycol (PEG) polymers. Experimental results demonstrate that the pristine ZGC NPs at a concentration of 0.5 mg mL(-1) induce hemolysis, erythrocyte morphology changes and delayed clotting, whereas no significant difference is observed with PEGylated ZGC (ZGC-PEG). However, neither ZGC nor ZGC-PEG caused thrombosis and inflammatory complement activation, which provides a basic foundation for in vivo imaging.