The interactions between bovine serum albumin and carboxybetaine-functionalized polysiloxanes in solution

Abstract

The interactions between carboxybetaine-functionalized polydimethylsiloxanes (PDMS-g-CB) and bovine serum albumin (BSA) in water solution were investigated from varied aspects based on different techniques, including fluorescence spectroscopy, UV-Vis spectroscopy, circular dichroism spectroscopy, isothermal titration calorimetry, and atomic force microscopy. Due to the weak interaction between PDMS-g-CB and BSA, another polymer with similar structure as PDMS-g-CB, i.e., quaternary ammonium salt-functionalized polydimethylsiloxanes (PDMS-g-QAS), was synthesized and chosen as the positive control, and the results indicated that the free PDMS-g-CB in solution could exhibit good resistance against proteins, which was mainly due to the zwitterions-side groups’ binding ability between PDMS chain and protein. Both the characterization methods and the results could help us to understand the interaction between free water-soluble polymers and protein, and extend the application of PDMS-g-CB and design new antifouling materials.