Linoleic acid-modified liposomes for the removal of protein-bound toxins: An in vitro study

Introduction: Protein-bound uremic toxins (PBUTs) and liver failure-related cholestatic solutes are associated with adverse outcomes in patients with chronic kidney disease (CKD) and liver failure, respectively, and are not easily removed by traditional dialysis therapies. We constructed linoleic acid-modified liposomes (LA-liposomes) as indirect adsorbent in the dialysate, and evaluated their effects on the clearance of the representative PBUTs and cholestatic solutes. Methods: The LA-liposomes were prepared by the thin-film hydration method. The binding rates of liposomes and protein-bound solutes were detected by the ultrafiltration column. The in vitro dialysis experiments were performed using both non-current and current devices to assay the clearing efficiency of the dialysate supported by LA-liposomes. Results: The LA-liposomes exhibited good binding properties to the PBUTs, bilirubin and bile acids. The LA-liposome dialysate showed higher solute reduction rates of the representative PBUTs and cholestatic solutes than the traditional dialysate or dialysate supported by the unmodified plain liposomes. Also, albumin binding of the PBUTs was significantly inhibited by the addition of linoleic acid (LA), and the removal efficiency of PBUTs was greatly enhanced by the combination of indirect adsorbent LA-liposomes and LA as the competitive displacer. Conclusion: LA-liposomes were efficient in the clearance of the representative PBUTs and liver failure-related solutes. Moreover, the combination of indirect adsorbent LA-liposomes and competitive displacer suggested a potential application for the extremely highly-bound solutes.