title: A mild process to design silk scaffolds with reduced β-sheet structure and various topographies at the nanometer scale.
abstract: Three-dimensional (3-D) porous silk scaffolds with good biocompatibility and minimal immunogenicity show promise in a range of tissue regeneration applications. However, the challenge remains to effectively fabricate their microstructures and mechanical properties to satisfy the specific requirements of different tissues. In this study, silk scaffolds were fabricated to form an extracellular matrix (ECM) mimetic nanofibrous architecture using a mild process. A slowly increasing concentration process was applied to regulate silk self-assembly into nanofibers in aqueous solution. Then glycerol was blended with the nanofiber solution and induced silk crystallization in the lyophilization process, endowing freeze-dried scaffolds with water stability. The glycerol was leached from the scaffolds, leaving a similar porous structure at the micrometer scale but different topographies at the nanoscale. Compared to previous salt-leached and methanol-annealed scaffolds, the present scaffolds showed lower β-sheet content, softer mechanical property and improved cell growth and differentiation behaviors, suggesting their promising future as platforms for controlling stem cell fate and soft tissue regeneration.
authors.affiliation: National Engineering Laboratory for Modern Silk & Collaborative Innovation Center of Suzhou Nano Science and Technology, Soochow University, Suzhou 215123, People's Republic of China.
authors.forename: Yazhen
authors.initials: Y
authors.lastname: Pei
authors.affiliation: National Engineering Laboratory for Modern Silk & Collaborative Innovation Center of Suzhou Nano Science and Technology, Soochow University, Suzhou 215123, People's Republic of China.
authors.forename: Xi
authors.initials: X
authors.lastname: Liu
authors.affiliation: National Engineering Laboratory for Modern Silk & Collaborative Innovation Center of Suzhou Nano Science and Technology, Soochow University, Suzhou 215123, People's Republic of China.
authors.forename: Shanshan
authors.initials: S
authors.lastname: Liu
authors.affiliation: National Engineering Laboratory for Modern Silk & Collaborative Innovation Center of Suzhou Nano Science and Technology, Soochow University, Suzhou 215123, People's Republic of China. Electronic address: Lvqiang78@suda.edu.cn.
authors.forename: Qiang
authors.initials: Q
authors.lastname: Lu
authors.affiliation: Regenerative Medicine Center, First Affiliated Hospital of Dalian Medical University, No. 222 Zhongshan Road, Dalian 116011, People's Republic of China.
authors.forename: Jing
authors.initials: J
authors.lastname: Liu
authors.affiliation: National Engineering Laboratory for Modern Silk & Collaborative Innovation Center of Suzhou Nano Science and Technology, Soochow University, Suzhou 215123, People's Republic of China; Department of Biomedical Engineering, Tufts University, Medford, MA 02155, USA.
authors.forename: David L
authors.initials: DL
authors.lastname: Kaplan
authors.affiliation: Research Center of Materials Science, Beijing Institute of Technology, Beijing 100081, People's Republic of China.
authors.forename: Hesun
authors.initials: H
authors.lastname: Zhu
mesh_terms: D000818:Animals; D002454:Cell Differentiation; D049109:Cell Proliferation; D002478:Cells, Cultured; D008422:Materials Testing; D059630:Mesenchymal Stem Cells / Q000166:cytology / Q000378:metabolism*; D016062:Porosity; D017433:Protein Structure, Secondary; D051381:Rats; D017207:Rats, Sprague-Dawley; D047011:Silk / Q000737:chemistry*; D054457:Tissue Scaffolds / Q000737:chemistry*
chemical_list: D047011:Silk
keywords: ECM-mimic; Reduced β-sheet structure; Silk; Soft tissue