Molecularly imprinted composite cryogel for extracorporeal removal of uric acid

In this study, uric acid (UA)-imprinted poly (hydroxyethyl methacrylate-N-methacryloyl-amido-L-cysteine methyl ester)-Fe³⁺ [poly(HEMA-MAC)-Fe³⁺] nanoparticle-embedded poly(acrylamide-methyl methacrylate) cryogel [p(AAm-MMA)-MIP] was synthesized for selective UA adsorption. The nanoparticles were prepared via molecular imprinting. The prepared p(AAm-MMA)-MIP cryogel was characterized by Fourier-transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), and swelling test. The swelling degree of the p(AAm-MMA)-MIP cryogel was determined as to 7.56 g H₂O/g cryogel. The prepared cryogel was used for UA adsorption from aqueous solution.The effects of pH (4.0-8.0), initial UA concentration (5-40 mg/L), temperature (4 °C, 25 °C and 35 °C) and contact time on the UA adsorption capacity were detailedly investigated. UA adsorption data were applied to Langmuir and Freundlich isotherm models. The adsorption data were well fitted with pseudo-second order kinetic model. The thermodynamic parameters (ΔG ͦ, ΔH ͦ, ΔS^o) demonstrated that the adsorption process was endothermic and spotaneous at 4 °C, 25 °C and 35 °C. The cryogel was also used for UA adsorption from human serum. The effects of the composite cryogel treatment on blood cells and hemostatic parameters were evaluated by using hemogram analyses, coagulation studies, thromboelastography and platelet aggregation studies. The results showed that the cryogel treatment has an allowable effect on blood cell counts and hemostatic parameters demonstrating the applicability of prepared composite cryogel for UA removal from human serum.