title: RGD-functionalized bioengineered spider dragline silk biomaterial.
abstract: Spider silk fibers have remarkable mechanical properties that suggest the component proteins could be useful biopolymers for fabricating biomaterial scaffolds for tissue formation. Two bioengineered protein variants from the consensus sequence of the major component of dragline silk from Nephila clavipes were cloned and expressed to include RGD cell-binding domains. The engineered silks were characterized by CD and FTIR and showed structural transitions from random coil to insoluble beta-sheet upon treatment with methanol. The recombinant proteins were processed into films and fibers and successfully used as biomaterial matrixes to culture human bone marrow stromal cells induced to differentiate into bone-like tissue upon addition of osteogenic stimulants. The recombinant spider silk and the recombinant spider silk with RGD encoded into the protein both supported enhanced the differentiation of human bone marrow derived mesenchymal stem cells (hMSCs) to osteogenic outcomes when compared to tissue culture plastic. The recombinant spider silk protein without the RGD displayed enhanced bone related outcomes, measured by calcium deposition, when compared to the same protein with RGD. Based on comparisons to our prior studies with silkworm silks and RGD modifications, the current results illustrate the potential to bioengineer spider silk proteins into new biomaterial matrixes, while also highlighting the importance of subtle differences in silk sources and modes of presentation of RGD to cells in terms of tissue-specific outcomes.
authors.affiliation: Department of Biomedical Engineering, Department of Chemistry, Bioengineering and Biotechnology Center, Tufts University, 4 Colby Street, Medford, Massachusetts 02155, USA.
authors.forename: Elisabetta
authors.initials: E
authors.lastname: Bini
authors.forename: Cheryl Wong Po
authors.initials: CW
authors.lastname: Foo
authors.forename: Jia
authors.initials: J
authors.lastname: Huang
authors.forename: Vassilis
authors.initials: V
authors.lastname: Karageorgiou
authors.forename: Brandon
authors.initials: B
authors.lastname: Kitchel
authors.forename: David L
authors.initials: DL
authors.lastname: Kaplan
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D002478:Cells, Cultured; D002942:Circular Dichroism; D003001:Cloning, Molecular; D017931:DNA Primers; D019476:Insect Proteins / Q000737:chemistry* / Q000235:genetics; D008969:Molecular Sequence Data; D009842:Oligopeptides / Q000737:chemistry*; D015202:Protein Engineering; D011994:Recombinant Proteins / Q000737:chemistry / Q000235:genetics; D047011:Silk / Q000737:chemistry*; D017550:Spectroscopy, Fourier Transform Infrared; D013112:Spiders
chemical_list: D017931:DNA Primers; D019476:Insect Proteins; D009842:Oligopeptides; D011994:Recombinant Proteins; D047011:Silk; C047981:arginyl-glycyl-aspartic acid