Chondroitin-analogue decorated magnetic nanoparticles via a click reaction for selective adsorption of low-density lipoprotein

Abstract

The accumulation of low-density lipoprotein (LDL) in vascellum has been generally deemed to be a chief risk factor for the emergence of atherosclerotic cardiovascular disease (ACD), and until now, efficient and selective LDL removal has been a challenge in the clinical context. As one sort of sulfonated biomacromolecule, chondroitin presents a promising capability of cleaning LDL in the blood. However, its physiological functions normally have been restricted by its intrinsic nature, such as the inhomogeneity and uncontrollable sulfonate degree in structural characteristics. In this work, azide terminated chondroitin-analogue polymers with tunable sulfonate degrees and alkynyl modified magnetic nanoparticles (MNPs) were synthesized, respectively. Magnetic nano-adsorbents were sequentially fabricated through the azide–alkyne click reaction. Decoration of magnetic nanoparticles with functional polymers was confirmed by Fourier Transform Infrared spectroscopy (FT-IR), zeta potential measurement and transition electron microscopy (TEM). The LDL adsorption behaviours of modified magnetic nano-adsorbents presented significant variation due to the different saccharide and sulfonate ratios in the polymer chains, indicating the key roles of each pendant in the interaction with LDL molecules. Therefore, MNPs decorated with almost equal moles of saccharide and sulfonate units in polymer chains exhibited a higher affinity to LDL than the others. Due to its excellent magnetic response, the prepared nano-adsorbent realized the recyclability after a facile separation and elution process. Recycling and BSA adsorption experiments demonstrated the stable adsorption efficiency and selectivity for LDL, suggesting that the magnetic nano-adsorbent can act as an admirable material for LDL removal in potential clinical applications.