A magnetic polymer adsorbent based on porous polystyrene microspheres for efficient extraction of conotoxins in...

Conotoxins, isolated from the venom produced by marine snails of the Conus genus, are a range of bioactive, disulfide-rich peptides. However, their narrow therapeutic window and significant interindividual variability make the efficient and accurate detection of their concentration in biological fluids a "lifeline" for ensuring safe and effective clinical use. In this work, we employed α-conotoxin ImI (α-ImI) and ziconotide as model peptides. Inspired by the mechanisms through which these two peptides exert bioactivity, we fabricated and characterized porous polystyrene-based magnetic microspheres grafted with a terpolymer, poly (divinylbenzene-co-N-vinylpyrrolidone-co-vinylphosphonic acid), DVB-co-NVP-co-VPA, for the efficient capture of α-ImI and ziconotide from biofluid samples. The results implied that the modified DVB-co-NVP-co-VPA enhanced the selectivity and adsorption capability for α-ImI and ziconotide. The established method was characterized by good linearity (R² above 0.9993), acceptable sensitivity (LODs below 0.03 μg mL^-1), high accuracy (recoveries ranging from 85.3% to 92.9%) and excellent repeatability (RSDs varied from 1.3% to 2.8%). Furthermore, the adsorbent maintained good reusability over six adsorption-desorption cycles, indicating its potential as an efficient candidate for pharmacokinetic studies of conotoxins.