Immunogenicity, Pharmaceutics, and Properties of Recombinant <i>Aspergillus flavus</i> Uricase Modified by Citric Acid/Ethylenediamine Carbon Dots

Clinically, patients with gout are often treated with uricase (Uox)-based drugs. While these medications are effective, many patients suffer from immune rejection associated with their use. To reduce Uox's immunogenicity, it was modified with carbon dots synthesized from citric acid and ethylenediamine (CA/EDA-CDs), forming CA/EDA-Uox. The particle size, zeta potential, and main functional groups of CA/EDA-CDs and CA/EDA-Uox were characterized by transmission electron microscopy (TEM), FT-IR, and dynamic light scattering (DLS). CCK8 and flow cytometry were used to detect the survival rate of L02 cells treated with CA/EDA-CDs and CA/EDA-Uox, respectively. After treatment with 1% CA/EDA-Uox for 2 weeks, IgG and IgM titers in rats were detected by ELISA. The particle size of CA/EDA-CDs is mainly 5 nm, and zeta potential is distributed in -10.3 mV and 5.8 mV. The cell survival rate and the number of fluorescently labeled cells were the highest in 1% CA/EDA-CDs and 1% CA/EDA-Uox treatment groups, respectively. No antibody was detected in 1% CA/EDA-Uox treated rats. The contents of IL-2, 6, 10, and TNF-β in the blood of quails were significantly lower than those in Uox group (p < 0.01). The cytotoxicity of 1% CA/EDA-CDs and 1% CA/EDA-Uox were the lowest; there were less antibodies produced by 1% CA/EDA-Uox in rats. CA/EDA-Uox exhibits satisfactory safety, low immunogenicity, and favorable pharmacological properties. It holds promise for progression to the clinical trials and eventual clinical application.