title: Braided and Stacked Electrospun Nanofibrous Scaffolds for Tendon and Ligament Tissue Engineering.
abstract: Tendon and ligament injuries are a persistent orthopedic challenge given their poor innate healing capacity. Nonwoven electrospun nanofibrous scaffolds composed of polyesters have been used to mimic the mechanics and topographical cues of native tendons and ligaments. However, nonwoven nanofibers have several limitations that prevent broader clinical application, including poor cell infiltration, as well as tensile and suture-retention strengths that are inferior to native tissues. In this study, multilayered scaffolds of aligned electrospun nanofibers of two designs-stacked or braided-were fabricated. Mechanical properties, including structural and mechanical properties and suture-retention strength, were determined using acellular scaffolds. Human bone marrow-derived mesenchymal stem cells (MSCs) were seeded on scaffolds for up to 28 days, and assays for tenogenic differentiation, histology, and biochemical composition were performed. Braided scaffolds exhibited improved tensile and suture-retention strengths, but reduced moduli. Both scaffold designs supported expression of tenogenic markers, although the effect was greater on braided scaffolds. Conversely, cell infiltration was superior in stacked constructs, resulting in enhanced cell number, total collagen content, and total sulfated glycosaminoglycan content. However, when normalized against cell number, both designs modulated extracellular matrix protein deposition to a similar degree. Taken together, this study demonstrates that multilayered scaffolds of aligned electrospun nanofibers supported tenogenic differentiation of seeded MSCs, but the macroarchitecture is an important consideration for applications of tendon and ligament tissue engineering.
authors.affiliation: 1 Department of Orthopaedic Surgery, Center for Cellular and Molecular Engineering , Pittsburgh, Pennsylvania.|2 McGowan Institute for Regenerative Medicine, University of Pittsburgh , Pittsburgh, Pennsylvania.
authors.forename: Benjamin B
authors.initials: BB
authors.lastname: Rothrauff
authors.affiliation: 1 Department of Orthopaedic Surgery, Center for Cellular and Molecular Engineering , Pittsburgh, Pennsylvania.|3 Department of Bioengineering, Swanson School of Engineering , Pittsburgh, Pennsylvania.
authors.forename: Brian B
authors.initials: BB
authors.lastname: Lauro
authors.affiliation: 1 Department of Orthopaedic Surgery, Center for Cellular and Molecular Engineering , Pittsburgh, Pennsylvania.|3 Department of Bioengineering, Swanson School of Engineering , Pittsburgh, Pennsylvania.
authors.forename: Guang
authors.initials: G
authors.lastname: Yang
authors.affiliation: 2 McGowan Institute for Regenerative Medicine, University of Pittsburgh , Pittsburgh, Pennsylvania.|3 Department of Bioengineering, Swanson School of Engineering , Pittsburgh, Pennsylvania.|4 Orthopaedic Robotics Laboratory , Department of Orthopaedic Surgery, Pittsburgh, Pennsylvania.
authors.forename: Richard E
authors.initials: RE
authors.lastname: Debski
authors.affiliation: 3 Department of Bioengineering, Swanson School of Engineering , Pittsburgh, Pennsylvania.|4 Orthopaedic Robotics Laboratory , Department of Orthopaedic Surgery, Pittsburgh, Pennsylvania.
authors.forename: Volker
authors.initials: V
authors.lastname: Musahl
authors.affiliation: 1 Department of Orthopaedic Surgery, Center for Cellular and Molecular Engineering , Pittsburgh, Pennsylvania.|2 McGowan Institute for Regenerative Medicine, University of Pittsburgh , Pittsburgh, Pennsylvania.|3 Department of Bioengineering, Swanson School of Engineering , Pittsburgh, Pennsylvania.
authors.forename: Rocky S
authors.initials: RS
authors.lastname: Tuan
mesh_terms: D006801:Humans; D008022:Ligaments; D059630:Mesenchymal Stem Cells / Q000166:cytology / Q000378:metabolism*; D057139:Nanofibers / Q000737:chemistry*; D013710:Tendons; D023822:Tissue Engineering; D054457:Tissue Scaffolds / Q000737:chemistry*
keywords: electrospinning; nanofibrous scaffold; tendon tissue engineering