A cation‐exchange material for protein separations based on grafting of thiol‐terminated sulfopropyl methacrylate telomers onto hydrophilized monodisperse divinylbenzene particles

Abstract

A strong cation-exchange separation material has been prepared from monodisperse divinylbenzene particles modified by a "grafting to" approach, utilizing as anchoring points epoxy groups introduced onto the surface of the particles via oxidation of residual vinyl groups. The grafted chains consisted of thiol-terminated telomers of sulfopropyl methacrylate prepared by iniferter mediated polymerization, and grafting was performed by reaction of the corresponding thiolate anion with the surface epoxy groups. Attachment through epoxy moieties that were subsequently converted into 2,3-propanediol groups increased the hydrophilicity of the polymeric particles and incubation experiments showed no signs of the proteins denaturing on the column during an extended contact time of 1 h at room temperature. The performance of the grafted material was demonstrated by the chromatographic separation of cytochrome C, lysozyme, myoglobin, and ribonuclease A, in a cation-exchange mode.

Functionalization of epoxy‐based monoliths for ion exchange chromatography of proteins

“…Flexible spacer arms cover the surface with functional groups to avoid nonspecific interaction, reducing contortion of bound proteins, and could, to a certain extent, enhance the capacity [11,12]. Introduction of tentacle functionality onto the carrier surface can be realized by a "grafting to" approach with readymade functional telomers [5]. However for charged tentacles, the telomer technique is prone to produce low grafting density due to the electrostatic and steric hindrance from polymer brushes already attached.…”

“…retained and eluted in the void volumes with both EXP-SO 3 and EXP-IDA. The elution order of the retained protein probes agrees well with the literature [5,24,25]. Stronger retention for the proteins was observed with EXP-SO 3 than EXP-IDA, i.e., higher salt concentration was required to elute the proteins with the strong cation exchange sorbent than with the weak.…”

Quantification of Grafting Densities Achieved via Modular “Grafting‐to” Approaches onto Divinylbenzene Microspheres

“…A further highly useful comparison comes from microspheres (identical to those employed in the current study) that were also modified via a grafting-to approach, yet with a different polymer. Irgum and colleagues [41] provide loading capacities of microspheres grafted with sulfur containing telomers via a ring-opening reaction on the surface of the microspheres. The resulting core-shell microspheres were analyzed by these authors via elemental analysis using sulfur as a chemical sensor to determine the grafting densities.…”

Synthesis of Microspheres as Versatile Functional Scaffolds for Materials Science Applications

“…In addition, Irgum and co-workers established poly(sulfopropyl methacrylate)grafted microspheres as cation-exchange materials for protein separations. [5] Furthermore, the precipitation polymerization technique has been employed to synthesize molecularly imprinted microspheres, [6,7] which have been successfully tested as devices for the detection of degradation products of chemical warfare agents [8] and towards their chiral selectivity. [9] In the following, a summary of the state-of-the art synthesis and modification of highly cross-linked pDVB microspheres and their derivates is presented.…”