title: Effect of film thickness on the antifouling performance of poly(hydroxy-functional methacrylates) grafted surfaces.
abstract: The development of nonfouling biomaterials to prevent nonspecific protein adsorption and cell/bacterial adhesion is critical for many biomedical applications, such as antithrombogenic implants and biosensors. In this work, we polymerize two types of hydroxy-functional methacrylates monomers of 2-hydroxyethyl methacrylate (HEMA) and hydroxypropyl methacrylate (HPMA) into polymer brushes on the gold substrate via surface-initiated atom transfer radical polymerization (SI-ATRP). We systematically examine the effect of the film thickness of polyHEMA and polyHPMA brushes on their antifouling performance in a wide range of biological media including single-protein solution, both diluted and undiluted human blood serum and plasma, and bacteria culture. Surface plasmon resonance (SPR) results show a strong correlation between antifouling property and film thickness. Too thin or too thick polymer brushes lead to large protein adsorption. Surfaces with the appropriate film thickness of ∼25-45 nm for polyHPMA and ∼20-45 nm for polyHEMA can achieve almost zero protein adsorption (<0.3 ng/cm(2)) from single-protein solution and diluted human blood plasma and serum. For undiluted human blood serum and plasma, polyHEMA brushes at a film thickness of ∼20-30 nm adsorb only ∼3.0 and ∼3.5 ng/cm(2) proteins, respectively, while polyHPMA brushes at a film thickness of ∼30 nm adsorb more proteins of ∼13.5 and ∼50.0 ng/cm(2), respectively. Moreover, both polyHEMA and polyHPMA brushes with optimal film thickness exhibit very low bacteria adhesion. The excellent antifouling ability and long-term stability of polyHEMA and polyHPMA brushes make them, especially for polyHEMA, effective and stable antifouling materials for usage in blood-contacting devices.
authors.affiliation: Department of Chemical and Biomolecular Engineering, The University of Akron, Akron, Ohio 44325, USA.
authors.forename: Chao
authors.initials: C
authors.lastname: Zhao
authors.forename: Lingyan
authors.initials: L
authors.lastname: Li
authors.forename: Qiuming
authors.initials: Q
authors.lastname: Wang
authors.forename: Qiuming
authors.initials: Q
authors.lastname: Yu
authors.forename: Jie
authors.initials: J
authors.lastname: Zheng
mesh_terms: D000327:Adsorption; D001798:Blood Proteins / Q000378:metabolism*; D002448:Cell Adhesion / Q000187:drug effects*; D020099:Coated Materials, Biocompatible / Q000737:chemistry* / Q000494:pharmacology; D006801:Humans; D008689:Methacrylates; D011108:Polymers
chemical_list: D001798:Blood Proteins; D020099:Coated Materials, Biocompatible; D008689:Methacrylates; D011108:Polymers; C005044:hydroxyethyl methacrylate; C032802:hydroxypropyl methacrylate