title: Biomaterials derived from silk-tropoelastin protein systems.
abstract: A structural protein blend system based on silkworm silk fibroin and recombinant human tropoelastin is described. Silk fibroin, a semicrystalline fibrous protein with beta-sheet crystals provides mechanical strength and controllable biodegradation, while tropoelastin, a noncrystallizable elastic protein provides elasticity. Differential scanning calorimetry (DSC) and temperature modulated DSC (TMDSC) indicated that silk becomes miscible with tropoelastin at different blend ratios, without macrophase separation. Fourier transform infrared spectroscopy (FTIR) revealed secondary structural changes of the blend system (beta-sheet content) before and after methanol treatment. Atomic Force Microscopy (AFM) nano-indentation demonstrated that blending silk and tropoelastin at different ratios resulted in modification of mechanical features, with resilience from approximately 68%- approximately 97%, and elastic modulus between 2 and 9 Mpa, depending on the ratio of the two polymers. Some of these values are close to those of native aortic elastin or elastin-like polypeptides. Significantly, during blending and drying silk-tropoelastin form micro- and nano-scale porous morphologies which promote human mesenchymal stem cell attachment and proliferation. These blends offer a new protein biomaterial system for cell support and tailored biomaterial properties to match mechanical needs.
authors.affiliation: Department of Biomedical Engineering, Tufts University, Medford, MA 02155, USA.
authors.forename: Xiao
authors.initials: X
authors.lastname: Hu
authors.forename: Xiuli
authors.initials: X
authors.lastname: Wang
authors.forename: Jelena
authors.initials: J
authors.lastname: Rnjak
authors.forename: Anthony S
authors.initials: AS
authors.lastname: Weiss
authors.forename: David L
authors.initials: DL
authors.lastname: Kaplan
mesh_terms: D000328:Adult; D000818:Animals; D001672:Biocompatible Materials / Q000737:chemistry*; D012831:Bombyx / Q000737:chemistry*; D002152:Calorimetry, Differential Scanning; D002470:Cell Survival; D002478:Cells, Cultured; D004548:Elasticity; D004549:Elastin; D005349:Fibroins / Q000737:chemistry*; D006801:Humans; D008297:Male; D059630:Mesenchymal Stem Cells / Q000166:cytology; D018625:Microscopy, Atomic Force; D011994:Recombinant Proteins / Q000737:chemistry; D017550:Spectroscopy, Fourier Transform Infrared; D014333:Tropoelastin / Q000737:chemistry*
chemical_list: D001672:Biocompatible Materials; D011994:Recombinant Proteins; D014333:Tropoelastin; C482288:fibroin, silkworm; D004549:Elastin; D005349:Fibroins