A high-density 4-vinylpyridine membrane for rapid purification of antibodies†

In order to further investigate the mechanism of action of rituximab in humans and its biotransformation, it is essential to obtain high purity rituximab while maintaining its structural and functional integrity. In this study, we proposed and fabricated a small-molecule 4-vinylpyridine-modified high-density membrane material (P4VP@M) using the surface-initiated atom transfer radical polymerization (SI-ATRP) method. This approach can overcome the limitations of conventional enrichment materials, such as long incubation time and low adsorption capacity. P4VP@M incorporates high-density HEMA polymer brushes to prevent non-specific protein adsorption and 4-vinylpyridine polymer brushes for high-performance rituximab enrichment under mild conditions. In addition, P4VP@M has high permeability, hydrophilicity and mechanical strength. Compared to previous methods, this novel material showed excellent rituximab binding capacity (100.3 mg g⁻¹), shorter processing time (only 15 min), and lower cost (only $2). Notably, P4VP@M was able to purify rituximab rapidly and efficiently from the mixture samples and exhibited good selectivity, recovery (>92.6%) and purity (>94.8%). Thus, this proposed purification strategy using P4VP@M has great potential in enriching target proteins from complex samples, as well as contributing to the in-depth study of their biological functions.