Langmuir 2008, 24, 9211-9214
9211
Film Thickness Dependence of Protein Adsorption from Blood Serum and Plasma onto Poly(sulfobetaine)-Grafted Surfaces Wei Yang,†,‡ Shengfu Chen,† Gang Cheng,† Hana Vaisocherova´,† Hong Xue,† Wei Li,‡ Jinli Zhang,‡ and Shaoyi Jiang*,† Department of Chemical Engineering, UniVersity of Washington, Box 351750, Seattle, Washington 98195, School of Chemical Engineering and Technology, Tianjin UniVersity, Tianjin 300072, P.R.China ReceiVed May 14, 2008. ReVised Manuscript ReceiVed June 27, 2008 In this work, we investigate protein adsorption from single protein solutions and complex media such as 100% blood serum and plasma onto poly(sulfobetaine methacrylate) (polySBMA)-grafted surfaces via atom transfer radical polymerization (ATRP) at varying film thicknesses. It is interesting to observe that protein adsorption exhibits a minimum at a medium film thickness. Results show that the surface with 62 nm polySBMA brushes presents the best nonfouling character in 100% blood serum and plasma although all of these surfaces are highly resistant to nonspecific protein adsorption from single fibrinogen and lysozyme solutions. Surface resistance to 100% blood serum or plasma is necessary for many applications from blood-contacting devices to drug delivery. This work provides a new in vitro evaluation standard for the application of biomaterials in vivo.
Introduction There is a significant need for the development of novel nonfouling materials for applications such as biosensors, biomaterials, drug delivery vehicles, and marine coatings.1,2 One of the most widely studied nonfouling materials is poly(ethylene glycol) (PEG) or oligo(ethylene glycol) (OEG).3–7 However, PEG and OEG can decompose, especially in the presence of oxygen and transition-metal ions found in most common biochemical solutions.8–10 Another class of nonfouling materials is the phosphorylcholine (PC)11–13 family of materials, but these monomers are generally difficult to synthesize. Recently, zwitterionic materials such as sulfobetaine methacrylate (SBMA) and carboxybetaine methacrylate (CBMA)14,15 and mixed-charge materials16 have been shown to have ultra-low protein adsorption17 (fibrinogen adsorption
