Exploring Chromium-Based MOF for Uremic Toxin Capture: A Promising Alternative Strategy for Affordable Dialysis Solutions.

The progressive accumulation of uremic toxins is a defining biochemical hallmark of renal dysfunction and continues to challenge the efficiency of existing dialysis technologies. Advancing sorbent-assisted purification systems, therefore, requires material capable of selectively capturing structurally diverse metabolites under physiologically relevant conditions. In this work, we evaluate a hydrolytically robust chromium-based MOF, Cr-IA, as a multifunctional adsorbent for four clinically significant uremic solutes: creatinine, uric acid, p-cresol, and hippuric acid. Leveraging its well-defined pore network, accessible coordination sites, and exceptional aqueous stability, Cr-IA demonstrates strong and toxin-specific adsorption behavior not only in water but also across physiologically relevant buffers (HEPES, PBS and Tyrode solutions) and real-sample matrices, including urine-mimicking solution and human blood serum. Both kinetic and thermodynamic evaluations further reveal that adsorption proceeds through diffusion-dominated, entropy-driven physisorption, consistent with pseudo-first-order, mixed-kinetic, and Elovich model behavior depending on the analyte. A comprehensive set of concentration, pH, and temperature-dependent adsorption experiments was performed to assess how environmental factors influence toxin uptake. UV-Vis. kinetic measurements show rapid adsorption for creatinine, hippuric acid, and p-cresol, while uric acid consistently displays the highest affinity, maintaining strong uptake even in protein-rich serum. Cr-IA also exhibits predictable, parameter-responsive adsorption behavior, reflecting efficient diffusion pathways and stable host-guest interactions across all tested media. Spectroscopic and surface analyses (FTIR, XPS, and zeta potential) further confirm that adsorption is governed by a synergistic combination of coordination interactions at Cr(III) centers, hydrogen bonding, and π-π interactions, with secondary electrostatic contributions. Importantly, the material retains its adsorption hierarchy and performance in biologically crowded matrices, demonstrating structural resilience and practical biomedical applicability. These findings establish Cr-IA as a promising candidate for low-cost sorbent-assisted dialysis, extracorporeal detoxification, and next-generation artificial kidney systems, providing a stable platform for effective uremic toxin management.