A Novel Silica Hybrid Nanoparticle with Zwitterion-Functionalized Polymer Chains for Highly Efficient N-Glycan Enrichment

N-Glycosylation is one of the most common and important protein posttranslational modifications. Structural aberrations of the N-glycans branching from glycoproteins are closely related to various disease occurrences and progressions. Therefore, global systematic identification of disease-related N-glycans not only largely facilitates the understanding of their cellular functions but also promotes the development of new diagnostic and therapeutic biomarkers. However, N-glycans are low in abundance and hydrophilic, thereby hindering high-throughput, and large-scale N-glycan analysis and N-glycoproteome research. Here, a zwitterion-functionalized polymer brush-grafted silica hybrid hydrophilic material (poly-SBMA-S) was fabricated by in situ growth of polymeric [2-(methacryloyloxy)ethyl]dimethyl(3-sulfopropyl)ammonium hydroxide (SBMA) chains on porous silica particles through a surface-initiated atom transfer radical polymerization technique, and it was used as a new stationary phase for highly selective N-glycan enrichment. Human plasma demonstrated 64 N-glycans due to the densely packed polyzwitterion chains and the significantly increased coverage of hydrophilic binding sites, demonstrating the high potential of the new hydrophilic matrix in the profiling and analysis of N-glycans and other hydrophilic targets.