A Closed-Loop Cascade Strategy for On-Demand Regulation of Uric Acid

Despite that the current anti-hyperuricemia drugs can effectively reduce uric acid (UA) levels, imprecise medication dosage or uncontrolled lowering of UA levels may result in undesired effects. To address this issue, a closed-loop cascade strategy based on a biocompatible network composite, NW-FPNP/uricase (UOX), is proposed for on-demand regulation of UA levels. NW-FPNP/UOX is constructed by encapsulation of UOX) as UA-responsive element and FPNP, a nanoparticle of phenylboronic acid modified xanthine oxidase (XOD) inhibitor febuxostat, as H₂O₂-sensitive element with AMP/Gd³⁺ network. It interrelates the UA metabolization and generation processes into a closed loop of cascade reactions involving UOX-catalyzed UA metabolization and H₂O₂ generation, H₂O₂-triggered febuxostat regeneration and XOD inhibition, and XOD-catalyzed UA generation. Through UA level-dependent auto-adjustment of XOD activity, specially 6% at 600 × 10^-6 m UA compared to 82% at 100 × 10^-6 m, UA levels can be regulated to an appropriate range through dynamically balancing UA metabolization and generation. This biocompatible on-demand UA regulation system prevents the overdose of UA-lowering medications and avoids hypouricemia in hyperuricemia treatment, demonstrating great potential in intelligent UA level management. This work also introduces a new concept of a closed-loop cascade strategy for on-demand regulation of biochemical indicators within specific thresholds.