Tailor-Made Nanoporous Metal-Organic Frameworks Via Molecular Engineering for Bilirubin-Specific Capture from Liver...

Overcoming the albumin-bilirubin binding barrier to achieve specific recognition and high-efficiency capture of blood bilirubin remains a major clinical challenge in treating patients with hyperbilirubinemia due to liver failure, cholestasis, or other related conditions. Here, a molecular engineering-assisted functionalization strategy is proposed: programming the coordination environment of nanocrystalline frameworks with monodentate carboxylic acid ligands of varied carbon chain lengths to construct a family of zirconium-based UiO-66 nanoporous frameworks that act as bilirubin-specific molecular capture traps. The experimental results and molecular dynamics simulations confirm that the newly engineered UiO-66 nanoporous framework rapidly enriched albumin-bound bilirubin through short-range van der Waals/electrostatic effects; the internal Zr-μ₃-OH sites then formed directional Zr-pyrrole coordination with the bilirubin tetrapyrrole core, whereas albumin was physically excluded by the narrow apertures of the engineered nanoporous framework (average 7.6 Å), breaking the "albumin barrier" without competitive displacement. Dense intrapore hydrogen-bonding networks and π-π stacking further strengthen bilirubin-specific complexation. The computed adsorption energy (ΔE_ads = - 3.7 eV) indicates spontaneous, diffusion-limited capture. In simulated blood experiments, the newly developed UiO-66 nanoporous framework achieves an ultrahigh bilirubin removal rate of ~ 97.9% with negligible albumin loss. Finally, clinical tests on plasma samples from ten liver failure patients revealed a 251% higher bilirubin removal capacity per unit mass than that of the commercial ion exchange resin (IER) within 3 h, while albumin leakage remained ≤ 2.58% (vs. ≥ 8.53% for commercial IER). This study reveals, for the first time, the advantages and translational prospects of molecularly engineered nanocrystalline frameworks as a clinically viable platform for high-efficiency blood bilirubin removal.