A new approach for the treatment of gut disease: Uricase attached nanomachines

Objective: This study aimed to evaluate in vitro effectiveness of the immobilization of uricase enzyme onto magnetic nanowires and the usability of these nanomachines for the treatment of gout. Material and Methods: Au/Ni/Au nanowires were prepared by sequential electro-deposition of gold, nickel and gold in a 60 µm thick and 200 nm-diameter alumina membrane, and the surface morphology and components of the nanowires were determined by SEM and EDX analysis. Uricase immobilization onto synthesized magnetic nanowires was performed covalently and they were coated with PEG. The activity of free and immobilized uricase enzyme was examined and optimum conditions, kinetic parameters, thermal, storage and operational stability, activity in presence of protease and its effectiveness in artificial human serum were determined. Results: It was observed that the diameters of uricase-attached nanowires increased from 226 nm to 247 nm, after coating with PEG as seen from the SEM images of Au/Ni/Au nanowires. Km values of free and immobilized uricases were calculated as 0.297 and 0.089 mM, respectively, and it was determined that Vmax value decreased at the end of immobilization. While optimum pH values of free and immobilized uricase enzymes were found to be 8.5 and 7.5, respectively, optimum temperature increased from 35 °C to 45 °C at the end of immobilization. It was determined that immobilized uricase showed higher stability than that of free enzyme in all studied conditions. When the efficiency of immobilized uricase in the oxidation of uric acid in artificial human serum was examined, it was found that immobilized enzyme showed an activity approximately 6 times higher than the free enzyme. Conclusion: In this thesis, it has been observed that synthesized uricase-attached nanomachines are effective in uric acid oxidation and have a promising potential for the treatment of gout for this purpose.