Biomimetic Anisotropic Polyvinyl Alcohol/Sodium Alginate/MXene Aerogel for Efficient Uremic Toxin Adsorption in Hemoperfusion

The accumulation of uremic toxins, which ultimately leads to renal failure, results in systemic complications and necessitates efficient and biocompatible removal strategies. This paper presents the preparation of a biomimetic anisotropic aerogel composed of polyvinyl alcohol (PVA), sodium alginate (SA), and MXenes (Ti₃C₂T_X) via directional freezing. Inspired by plant vascular bundles, the resulting vertically aligned porous structure enhances the mechanical stability of and mass transfer in the material. The aerogel with its high MXene loading and high surface utilization offers remarkable adsorption capacities for urea (221.77 mg g^-1) and creatinine (138.07 mg g^-1). In vitro assays confirm the excellent hemo- and cytocompatibility of the aerogel. In a rabbit model of acute ischemic kidney injury, two-hour hemoperfusion with the aerogel significantly lowers the urea (38.67 to 16.17 mmol L^-1) and creatinine levels (744.62 to 307.46 µmol L^-1) without observable toxicity. The multidimensional biomimetic multipore anisotropic MXene aerogel presented here is a structurally optimized and biologically safe adsorbent for efficient uremic toxin clearance and a promising alternative to conventional hemodialysis.