Amphiphilic diblock copolymers as functional surfaces for protein chromatography

TL;DR

This study explores the use of amphiphilic diblock copolymer surfaces as a simplified, single-step method to create porous, functional stationary phases for protein chromatography, aiming to improve packing uniformity and functionality.

Contribution

It demonstrates that a single-step functionalization of amphiphilic copolymer surfaces can produce effective, microporous stationary phases for protein chromatography, simplifying fabrication processes.

Findings

Hydrophilic surface confirmed by contact angle, FTIR, XPS.

Presence of microporous regions (~1-1.5 μm) suitable for cation exchange.

Potential application as stationary phase in protein chromatography.

Abstract

Stationary phase plays a crucial role in the operation of a protein chromatography column. Conventional resins composed of acrylic polymers and their derivatives contribute to heterogeneity of the packing of stationary phase inside these columns. Alternative polymer combinations through customized surface functionalization schemes which consist of multiple steps using static coating techniques are well known. In comparison, it is hypothesized that a single-step scheme is sufficient to obtain porous adsorbents as stationary phase for tuning surface morphology and protein immobilization. To overcome the challenge of heterogeneous packing and ease of fabrication at a laboratory scale, a change in the form factor of separation materials has been proposed in the form of functional copolymer surfaces. In the present work, an amphiphilic, block copolymer, poly(methyl methacrylate-co-methacrylic acid) has been chosen and fully characterized for its potential usage in protein chromatography. Hydrophilicity of the acrylic copolymer and abundance of carboxyl groups inherently on the copolymer surface have been successfully demonstrated through contact angle measurements, Fourier transform infrared (FTIR) and X-ray photoelectron spectroscopy (XPS) studies. Morphological studies indicate presence of a microporous region (nearly 1 to 1.5 $\mu$m pore size) that could be beneficial as a cation exchange media as part of the stationary phase in protein chromatography.