Temperature Responsive Polymer Conjugate Prepared by Grafting from Proteins toward the Adsorption and Removal of Uremic Toxin

In this study, temperature-responsive polymer-protein conjugate was synthesized using a grafting from concept by introducing a chain transfer agent (CTA) into bovine serum albumin (BSA). The BSA-CTA was used as a starting point for poly(N-isopropylacrylamide) (PNIPAAm) through reversible addition-fragmentation chain transfer polymerization. The research investigations suggest that the thermally responsive behavior of PNIPAAm was controlled by the monomer ratio to CTA, as well as the amount of CTA introduced to BSA. The study further synthesized the human serum albumin (HSA)-PNIPAAm conjugate, taking the advantage that HSA can specifically adsorb indoxyl sulfate (IS) as a uremic toxin. The HSA-PNIPAAm conjugate could capture IS and decreased the concentration by about 40% by thermal precipitation. It was also revealed that the protein activity was not impaired by the conjugation with PNIPAAm. The proposed strategy is promising in not only removal of uremic toxins but also enrichment of biomarkers for early diagnostic applications.

Automated summary

In this study, a temperature-responsive polymer-protein conjugate was synthesized by introducing a chain transfer agent (CTA) into bovine serum albumin (BSA). The research findings showed that the thermally responsive behavior of the polymer was controlled by the monomer ratio to CTA and the amount of CTA introduced to BSA. Furthermore, a human serum albumin (HSA)-poly(N-isopropylacrylamide) (PNIPAAm) conjugate was synthesized, which could specifically absorb the uremic toxin indoxyl sulfate (IS) and decrease its concentration by thermal precipitation.