Chromatographic separation of ovalbumin by novel chitosan and poly(butyl methacrylate) nanogels-based anion-exchange cryogels

A novel composite anion-exchange chitosan (CS) cryogel was synthesized via cryo-polymerization of CS and poly(butyl methacrylate) (pBMA) nanogels followed by graft polymerization with (vinylbenzyl)trimethylammonium chloride (VBTAC), which was then employed for the efficient separation of ovalbumin from egg white. Characteristics of the CS-pBMA-VBTAC cryogel were investigated experimentally, and the effects of sample volume, buffer pH and elution salt concentration on the ovalbumin separation were systematically evaluated. The results demonstrated that the present cryogel possessed an interconnected supermacroporous structure, high permeability, and excellent column efficiency. Notably, its adsorption capacity for bovine serum albumin reached 19.49 mg mL -1 , which is 4.4 and 5.6 times higher than that of VBTCA-grafted cryogels based on 2-hydroxyethyl methacrylate and acrylamide, respectively. Furthermore, the CS-pBMA-VBTAC cryogel maintained consistent adsorption performance over 20 runs of the replicate chromatographic separation of bovine serum albumin. Under optimal conditions of a loading volume equivalent to 6-fold column volumes, buffer pH 5.8 and elution with 0.8 M NaCl, the ovalbumin purity and recovery of 99.1 % and 96.1 %, were achieved, respectively, indicating that the CS-pBMA-VBTAC cryogel could be an excellent adsorbent material with promising potential for the high-efficiency separation of proteins like ovalbumin.