title: Thin film assembly of spider silk-like block copolymers.
abstract: We report the self-assembly of monolayers of spider silk-like block copolymers. Langmuir isotherms were obtained for a series of bioengineered variants of the spider silks, and stable monolayers were generated. Langmuir-Blodgett films were prepared by transferring the monolayers onto silica substrates and were subsequently analyzed by atomic force microscopy (AFM). Static contact angle measurements were performed to characterize interactions across the interface (thin film, water, air), and molecular modeling was used to predict 3D conformation of spider silk-like block copolymers. The influence of molecular architecture and volume fraction of the proteins on the self-assembly process was assessed. At high surface pressure, spider silk-like block copolymers with minimal hydrophobic block (f(A) = 12%) formed oblate structures, whereas block copolymer with a 6-fold larger hydrophobic domain (f(A) = 46%) formed prolate structures. The varied morphologies obtained with increased hydrophobicity offer new options for biomaterials for coatings and related options. The design and use of bioengineered protein block copolymers assembled at air-water interfaces provides a promising approach to compare 2D microstructures and molecular architectures of these amphiphiles, leading to more rationale designs for a range of nanoengineered biomaterial needs as well as providing a basis of comparison to more traditional synthetic block copolymer systems.
authors.affiliation: Department of Biomedical Engineering, Tufts University, 4 Colby Street, Medford, Massachusetts 02155, United States.
authors.forename: Sreevidhya T
authors.initials: ST
authors.lastname: Krishnaji
authors.forename: Wenwen
authors.initials: W
authors.lastname: Huang
authors.forename: Olena
authors.initials: O
authors.lastname: Rabotyagova
authors.forename: Eugenia
authors.initials: E
authors.lastname: Kharlampieva
authors.forename: Ikjun
authors.initials: I
authors.lastname: Choi
authors.forename: Vladimir V
authors.initials: VV
authors.lastname: Tsukruk
authors.forename: Rajesh
authors.initials: R
authors.lastname: Naik
authors.forename: Peggy
authors.initials: P
authors.lastname: Cebe
authors.forename: David L
authors.initials: DL
authors.lastname: Kaplan
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D008969:Molecular Sequence Data; D011108:Polymers / Q000737:chemistry* / Q000378:metabolism; D047011:Silk / Q000737:chemistry*; D013112:Spiders / Q000737:chemistry*; D013499:Surface Properties
chemical_list: D011108:Polymers; D047011:Silk