Highly negatively charged carbonized polymer dots/cellulose microspheres for efficient blood LDL removal

Hemoperfusion is an effective technique for removing low-density lipoprotein (LDL) from the bloodstream, with the performance of the adsorbent critical to its efficacy. This study innovatively introduces carbonized polymer dots (CPDs), which exhibit excellent biocompatibility and structural versatility, as a new functional ligand in hemoperfusion. A novel hemoperfusion adsorbent was prepared using cellulose microspheres as the support material. Here, we synthesized highly negatively charged CPDs using a hydrothermal method facilitated by nitric acid in the presence of citric acid and p-aminosalicylic acid. This process resulted in a stable zeta potential of -61.0 mV at physiological pH. Incorporating CPDs onto cellulose microspheres enhanced their negative charge from -1.22 mV to -31.0 mV, significantly improving LDL adsorption capacity to 80.3 ± 1.2 mg/g, with a removal rate of 80.3 ± 1.2%, which is 5.7 times greater than high-density lipoprotein (HDL). Furthermore, the introduction of CPDs improved the hemocompatibility of cellulose microspheres, resulting in a low hemolysis rate of 0.81% and minimal cytotoxic effects. FTIR and XPS characterization confirmed that the CPDs contain carboxyl and nitro groups, enhancing their negative charge properties. This research presents a new class of functional ligands for hemoperfusion adsorbents, indicating potential advancements in blood purification technologies.