Constructing Collagen Microsphere Adsorbent/Modified Polysulfone Blood Purification Membrane Mimicking Extracellular Matrix to Achieve High-Performance Adsorption of Bilirubin

Despite the efficacy of hemoperfusion in bilirubin elimination, conventional adsorbents face inherent limitations in simultaneously optimizing the adsorption capacity and biocompatibility. Similarly, while hemodialysis demonstrates effective clearance of small-molecule toxins, including unconjugated bilirubin, its therapeutic efficiency for BSA-conjugated bilirubin remains suboptimal due to molecular binding characteristics. In this study, collagen was utilized as the core material, enabling effective binding between its amino and carboxyl groups and bilirubin through electrostatic interactions and hydrogen bonding. Collagen porous microspheres were designed and developed as adsorbents for hemoperfusion, while collagen-modified polysulfone (PSF-Col) membranes were employed for hemodialysis. These materials address the limitations of poor hemocompatibility and low selectivity associated with conventional adsorbents. The adsorption capacities of unconjugated bilirubin were 67.89 mg/g for collagen porous microspheres and 57.18 mg/g for collagen-modified membranes, while the corresponding values for conjugated bilirubin were 55.59 and 44.73 mg/g, respectively. The combined adsorption capacity reached 155.11 mg/g (unconjugated) and 116.48 mg/g (conjugated bilirubin), exceeding the sum of individual material performances. The series of systems of hemoperfusion and blood dialysis provides a safer and more efficient treatment for patients with hyperbilirubinemia and hepatorenal syndrome.