title: Mesenchymal stem cell responses to bone-mimetic electrospun matrices composed of polycaprolactone, collagen I and nanoparticulate hydroxyapatite.
abstract: The performance of biomaterials designed for bone repair depends, in part, on the ability of the material to support the adhesion and survival of mesenchymal stem cells (MSCs). In this study, a nanofibrous bone-mimicking scaffold was electrospun from a mixture of polycaprolactone (PCL), collagen I, and hydroxyapatite (HA) nanoparticles with a dry weight ratio of 50/30/20 respectively (PCL/col/HA). The cytocompatibility of this tri-component scaffold was compared with three other scaffold formulations: 100% PCL (PCL), 100% collagen I (col), and a bi-component scaffold containing 80% PCL/20% HA (PCL/HA). Scanning electron microscopy, fluorescent live cell imaging, and MTS assays showed that MSCs adhered to the PCL, PCL/HA and PCL/col/HA scaffolds, however more rapid cell spreading and significantly greater cell proliferation was observed for MSCs on the tri-component bone-mimetic scaffolds. In contrast, the col scaffolds did not support cell spreading or survival, possibly due to the low tensile modulus of this material. PCL/col/HA scaffolds adsorbed a substantially greater quantity of the adhesive proteins, fibronectin and vitronectin, than PCL or PCL/HA following in vitro exposure to serum, or placement into rat tibiae, which may have contributed to the favorable cell responses to the tri-component substrates. In addition, cells seeded onto PCL/col/HA scaffolds showed markedly increased levels of phosphorylated FAK, a marker of integrin activation and a signaling molecule known to be important for directing cell survival and osteoblastic differentiation. Collectively these results suggest that electrospun bone-mimetic matrices serve as promising degradable substrates for bone regenerative applications.
authors.affiliation: Department of Physiology and Biophysics, University of Alabama at Birmingham, Birmingham, Alabama, United States of America.
authors.forename: Matthew C
authors.initials: MC
authors.lastname: Phipps
authors.forename: William C
authors.initials: WC
authors.lastname: Clem
authors.forename: Shane A
authors.initials: SA
authors.lastname: Catledge
authors.forename: Yuanyuan
authors.initials: Y
authors.lastname: Xu
authors.forename: Kristin M
authors.initials: KM
authors.lastname: Hennessy
authors.forename: Vinoy
authors.initials: V
authors.lastname: Thomas
authors.forename: Michael J
authors.initials: MJ
authors.lastname: Jablonsky
authors.forename: Shafiul
authors.initials: S
authors.lastname: Chowdhury
authors.forename: Andrei V
authors.initials: AV
authors.lastname: Stanishevsky
authors.forename: Yogesh K
authors.initials: YK
authors.lastname: Vohra
authors.forename: Susan L
authors.initials: SL
authors.lastname: Bellis
mesh_terms: D000327:Adsorption; D000818:Animals; D040761:Biomimetic Materials / Q000737:chemistry / Q000494:pharmacology*; D001842:Bone and Bones / Q000166:cytology*; D002448:Cell Adhesion / Q000187:drug effects; D015815:Cell Adhesion Molecules / Q000737:chemistry; D049109:Cell Proliferation / Q000187:drug effects; D024042:Collagen Type I / Q000737:chemistry*; D017886:Durapatite / Q000737:chemistry*; D004789:Enzyme Activation / Q000187:drug effects; D051416:Focal Adhesion Protein-Tyrosine Kinases / Q000378:metabolism; D006801:Humans; D008297:Male; D059630:Mesenchymal Stem Cells / Q000166:cytology / Q000187:drug effects* / Q000378:metabolism; D053758:Nanoparticles / Q000737:chemistry*; D010766:Phosphorylation / Q000187:drug effects; D011091:Polyesters / Q000737:chemistry*; D051381:Rats; D013718:Tensile Strength; D054457:Tissue Scaffolds / Q000737:chemistry
chemical_list: D015815:Cell Adhesion Molecules; D024042:Collagen Type I; D011091:Polyesters; C016240:polycaprolactone; D017886:Durapatite; D051416:Focal Adhesion Protein-Tyrosine Kinases