Abstract

An important challenge in many applications ranging from biomedical devices to ship hulls is the prevention of nonspecific biomolecular and microorganism attachment on surfaces. For example, nonspecific protein adsorption degrades the performance of surface-based diagnostic devices and causes an adverse effect on the healing process for implanted biomaterials. Our goals are to provide a fundamental understanding of molecular-level nonfouling mechanisms using an integrated experimental and simulation approach and to develop biocompatible and environmentally benign ultra low fouling materials based on design principles. Over the last few years, we have demonstrated that zwitterionic and mixed charge materials and surfaces are highly resistant to nonspecific protein adsorption from undiluted blood plasma/serum and to bacterial adhesion/biofilm formation. In addition to their excellent nonfouling properties, zwitterionic carboxybetaine-based materials have abundant functional groups for ligand immobilization while cationic zwitterionic precursors have self-sterilizing capabilities. Both simulation and experimental results show that the strong hydration of zwitterionic materials is responsible for their excellent nonfouling properties. At present, zwitterionic materials have been applied to a number of applications, including implantable medical devices, protein arrays, targeted drug/gene delivery carriers, antimicrobial coatings, and marine coatings.