title: Silk microfiber-reinforced silk hydrogel composites for functional cartilage tissue repair.
abstract: Cartilage tissue lacks an intrinsic capacity for self-regeneration due to slow matrix turnover, a limited supply of mature chondrocytes and insufficient vasculature. Although cartilage tissue engineering has achieved some success using agarose as a scaffolding material, major challenges of agarose-based cartilage repair, including non-degradability, poor tissue-scaffold integration and limited processing capability, have prompted the search for an alternative biomaterial. In this study, silk fiber-hydrogel composites (SF-silk hydrogels) made from silk microfibers and silk hydrogels were investigated for their potential use as a support material for engineered cartilage. We demonstrated the use of 100% silk-based fiber-hydrogel composite scaffolds for the development of cartilage constructs with properties comparable to those made with agarose. Cartilage constructs with an equilibrium modulus in the native tissue range were fabricated by mimicking the collagen fiber and proteoglycan composite architecture of native cartilage using biocompatible, biodegradable silk fibroin from Bombyx mori. Excellent chondrocyte response was observed on SF-silk hydrogels, and fiber reinforcement resulted in the development of more mechanically robust constructs after 42 days in culture compared to silk hydrogels alone. Thus, we demonstrate the versatility of silk fibroin as a composite scaffolding material for use in cartilage tissue repair to create functional cartilage constructs that overcome the limitations of agarose biomaterials, and provide a much-needed alternative to the agarose standard.
authors.affiliation: Department of Biomedical Engineering, Columbia University, New York, NY, USA.
authors.forename: Supansa
authors.initials: S
authors.lastname: Yodmuang
authors.affiliation: Department of Biomedical Engineering, Tufts University, Medford, MA, USA.
authors.forename: Stephanie L
authors.initials: SL
authors.lastname: McNamara
authors.affiliation: Department of Biomedical Engineering, Columbia University, New York, NY, USA.
authors.forename: Adam B
authors.initials: AB
authors.lastname: Nover
authors.affiliation: Department of Biotechnology, Indian Institute of Technology, Guwahati 781039, India.
authors.forename: Biman B
authors.initials: BB
authors.lastname: Mandal
authors.affiliation: Department of Biomedical Engineering, Columbia University, New York, NY, USA.
authors.forename: Monica
authors.initials: M
authors.lastname: Agarwal
authors.affiliation: Department of Biomedical Engineering, Tufts University, Medford, MA, USA.
authors.forename: Terri-Ann N
authors.initials: TA
authors.lastname: Kelly
authors.affiliation: Institute of Biomedical Engineering, School of Engineering and School of Medicine, National Taiwan University, Taipei, Taiwan.
authors.forename: Pen-hsiu Grace
authors.initials: PH
authors.lastname: Chao
authors.affiliation: Department of Biomedical Engineering, Columbia University, New York, NY, USA.
authors.forename: Clark
authors.initials: C
authors.lastname: Hung
authors.affiliation: Department of Biomedical Engineering, Tufts University, Medford, MA, USA.
authors.forename: David L
authors.initials: DL
authors.lastname: Kaplan
authors.affiliation: Department of Biomedical Engineering, Columbia University, New York, NY, USA. Electronic address: gv2131@columbia.edu.
authors.forename: Gordana
authors.initials: G
authors.lastname: Vunjak-Novakovic
mesh_terms: D000818:Animals; D040761:Biomimetic Materials / Q000737:chemistry*; D012831:Bombyx; D002356:Cartilage / Q000737:chemistry* / Q000293:injuries / Q000378:metabolism; D002417:Cattle; D002478:Cells, Cultured; D019902:Chondrocytes / Q000166:cytology / Q000378:metabolism*; D005349:Fibroins / Q000737:chemistry*; D020100:Hydrogels / Q000737:chemistry*; D012685:Sepharose / Q000737:chemistry; D054457:Tissue Scaffolds / Q000737:chemistry*
chemical_list: D020100:Hydrogels; C482288:fibroin, silkworm; D005349:Fibroins; D012685:Sepharose
keywords: Cartilage; Chondrocyte; Hydrogel; Silk; Tissue engineering