Systematic Comparison of Zwitterionic and Non-Zwitterionic Antifouling PolymerBrushes on a Bead-Based Platform

摘要

Nonspecific adsorption of biomolecules to solid surfaces, a process called biofouling, is a major concern in many biomedical applications. Great effort has been made in the development of antifouling polymer coatings that are capable of repelling the nonspecific adsorption of proteins, cells, and micro-organisms. In this respect, we herein contribute to understanding the factors that determine which polymer brush results in the best antifouling coating. To this end, we compared five different monomers: two sulfobetaines, a carboxybetaine, a phosphocholine, and a hydroxyl acrylamide. The antifouling coatings were analyzed using our previously described bead-based method with flow cytometry as the read-out system. This method allows for the quick and automated analysis of thousands of beads per second, enabling fast analysis and good statistics. We report the first direct comparison made between a sulfobetaine with opposite charges separated by two and three methylene groups and a carboxybetaine bearing two separating methylene groups. It was concluded that both the distance between opposite charges andthe nature of the anionic groups have a distinct effect on the antifoulingperformance. Phosphocholines and simple hydroxyl acrylamides are notoften compared with the betaines. However, here we found that theyperform equally well or even better, yielding the following overallantifouling ranking: HPMAA ≥ PCMA-2 ≈ CBMAA-2 > SBMAA-2> SBMAA-3 ≫ nonmodified beads (HPMAA being the best).