J. Phys. Chem. B 2008, 112, 15269–15274
15269
ARTICLES Ultralow Fouling Zwitterionic Polymers Grafted from Surfaces Covered with an Initiator via an Adhesive Mussel Mimetic Linkage Guozhu Li,†,‡ Hong Xue,† Gang Cheng,† Shengfu Chen,† Fengbao Zhang,‡ and Shaoyi Jiang*,† Department of Chemical Engineering, UniVersity of Washington, Seattle, Washington 98195, and School of Chemical Engineering and Technology, Tianjin UniVersity, Tianjin, 300072, People’s Republic of China ReceiVed: July 03, 2008; ReVised Manuscript ReceiVed: September 12, 2008
In this work, nonfouling zwitterionic polymers were grafted via surface-initiated atom transfer radical polymerization (ATRP) from surfaces covered with an adhesive catechol initiator. The catechol initiator was attached to both bare gold and amino-functionalized surfaces, and the nonfouling performances of the resulting polymer brushes were compared. Under optimal conditions, ultralow protein adsorption from both singleprotein solutions of fibrinogen and lysozyme and complex media of 10% blood serum and 100% blood plasma/ serum was achieved. Furthermore, the 3-day accumulation of Pseudomonas aeruginosa on the treated glass surfaces was studied in situ using a laminar flow chamber. The results showed that these zwitterionic coatings dramatically reduced the biofilm formation of P. aeruginosa as compared to the reference bare glass. Introduction Biofouling from proteins and bacteria at the solid-liquid interface needs to be suppressed for many biomedical and engineering applications. This includes the nonspecific adsorption of proteins on biosensor surfaces, stents, and cardiovascular implants, and the colonization of bacteria on catheters, contact lenses, and surgical tools. One of the most effective methods to prevent biofouling is to perform surface modification with nonfouling self-assembled monolayers (SAMs) or polymers. Our recent studies demonstrated for the first time that the surfaces grafted with zwitterionic poly(sulfobetaine methacrylate) (pSBMA) and poly(carboxybetaine methacrylate) (pCBMA) via surface-initiated atom transfer radical polymerization (ATRP) are highly resistant to nonspecific protein adsorption (i.e.,
