Dual stimulus-responsive renewable nanoadsorbent for selective adsorption of low-density lipoprotein in serum

Abstract Selective removal of ultra-high low-density lipoprotein (LDL) from the blood of hyperlipemia patients using hemoperfusion is considered an efficient method to prevent the deterioration of atherosclerotic cardiovascular disease. Based on the exceptional structure–function properties of multistimulus-responsive materials, we developed a magnetic photorenewable nanoadsorbent (Fe3O4@SiO2@Azo-COOH) with outstanding selectivity and regenerative characteristics, featuring functionalized azobenzene as the ligand. The dual-stimulus response endowed Fe3O4@SiO2@Azo-COOH with rapid separation and photoregenerative properties. The adsorbent demonstrated excellent removal efficiency of LDL with an adsorption capacity of 15.06 mg/g, and highly repetitive adsorption performance (≥5 cycles) under irradiation. Fe3O4@SiO2@Azo-COOH also exhibited remarkable adsorption properties and selectivity in human serum, with adsorption capacities of 10.93, 21.26 and 9.80 mg/g for LDL, total cholesterol and triglycerides and only 0.77 mg/g for high-density lipoprotein (HDL), resulting in a 93% selective adsorption difference (LDL/HDL). Complete green regeneration of the nanoadsorbent was achieved through a simple regeneration process, maintaining a recovery rate of 99.4% after five regeneration experiments. By combining dynamic perfusion experiment with micromagnetic microfluidics, the LDL content decreased by 16.6%. Due to its superior adsorption capacity and regenerative properties, the dual stimulus-responsive nanosorbent is considered a potential hemoperfusion adsorbent. Graphical Abstract