A Temperature-Responsive Boronate Core Cross-Linked Star (CCS) Polymer for Fast and Highly Efficient Enrichment of Glycoproteins.

Fast and highly efficient enrichment and separation of glycoproteins is essential in many biological applications, but the lack of materials with high capture capacity, fast, and efficient enrichment/separation makes it a challenge. Here, a temperature-responsive core cross-linked star (CCS) polymer with boronate affinity is reported for fast and efficient enriching and separating of glycoproteins from biological samples. The temperature-responsive CCS polymers containing boronic acid in its polymeric arms and poly(N-isopropyl acrylamide) in its cross-linked core are prepared using reversible addition-fragmentation chain transfer polymerization via an "arm-first" methodology. The soluble boronate polymeric arms of the CCS polymers provide a homogeneous reaction system and facilitate interactions between boronic acid and glycoproteins, which leads to a fast binding/desorption speed and high capture capacity. Maximum binding capacity of the prepared CCS polymer for horseradish peroxidase is determined to be 210 mg g-1 , which can be achieved within 20 min. More interestingly, the temperature-responsive CCS polymers exhibit rapid reversible thermal-induced volume phase transition by increasing the temperature from 15 to 30 °C, resulting in a facile and convenient sample collection and recovery for the target glycoproteins. Finally, the temperature-responsive CCS polymer is successfully applied to enrichment of low abundant glycoproteins.