Strong Surface Hydration and Salt Resistant Mechanism of a New Nonfouling Zwitterionic Polymer Based on Protein Stabilizer TMAO

Abstract

Zwitterionic polymers exhibit excellent nonfouling performance due to their strong surface hydrations. However, salt molecules may severely reduce the surface hydrations of typical zwitterionic polymers, making the application of these polymers in real biological and marine environments challenging. Recently, a new zwitterionic polymer brush based on the protein stabilizer trimethylamine N-oxide (TMAO) was developed as an outstanding nonfouling material. Using surface-sensitive sum frequency generation (SFG) vibrational spectroscopy, we investigated the surface hydration of TMAO polymer brushes (pTMAO) and the effects of salts and proteins on such surface hydration. It was discovered that exposure to highly concentrated salt solutions such as seawater only moderately reduced surface hydration. This superior resistance to salt effects compared to other zwitterionic polymers is due to the shorter distance between the positively and negatively charged groups, thus a smaller dipole in pTMAO and strong hydration around TMAO zwitterion. This results in strong bonding interactions between the O– in pTMAO and water, and weaker interaction between O– and metal cations due to the strong repulsion from the N+ and hydration water. Computer simulations at quantum and atomistic scales were performed to support SFG analyses. In addition to the salt effect, it was discovered that exposure to proteins in seawater exerted minimal influence on the pTMAO surface hydration, indicating complete exclusion of protein attachment. The excellent nonfouling performance of pTMAO originates from its extremely strong surface hydration that exhibits effective resistance to disruptions induced by salts and proteins.

Molecular Dynamics Study on Properties of Hydration Layers above Polymer Antifouling Membranes

“…To examine the structure of water molecules near the interface of antifouling membranes, we calculated the cosine of the angle between dipole of water and z-axis at different distances from the surface, as shown in Figure 6 . Obviously, for a random distribution, the cos θ should be close to 0 [ 38 ]. In the T4-DM membrane system, only water molecules close to membrane have a certain orientation, while water molecules farther away are randomly distributed.…”

“…The order of surface hydration ability or antifouling ability, T4-SB > T4-SP > T4-DM, was obtained. Next, we analyze the mechanisms for the difference in hydration ability from the monomer’s view, which serves as a model for the antifouling polymer membrane [ 38 ].…”

Enabling Tunable Water‐Responsive Surface Adaptation of PDMS via Metal–Ligand Coordinated Dynamic Networks

“…This study used a commercial SFG spectrometer from EKSPLA and all the SFG spectra were collected using ssp (s-polarized sum frequency signal, s-polarized input green beam, and p-polarized IR beam) polarization combinations. [78][79][80] In this work, to collect SFG spectra, right-angle CaF 2 prisms (Altos Photonics, Bozeman, MT) were used as substrates. PI and DIP materials used for SFG study were prepared by dissolving 1 g of the appropriate PDMS and the calculated amount of salt based on stoichiometry in separate 5 mL aliquots tetrahydrofuron (THF).…”

Bottlebrush inspired injectable hydrogel for rapid prevention of postoperative and recurrent adhesion

“…Recently, antifouling bottle-brush polymers have been extensively developed for the antifouling coating of in vivo implanted devices [ [14] , [15] , [16] ]. Among these, ultra-hydrophilic bottlebrush polymers have demonstrated excellent antifouling capability for non-specific proteins, bacteria, or fibroblasts [ 17 , 18 ].…”