title: Regulation of the osteogenesis of pre-osteoblasts by spatial arrangement of electrospun nanofibers in two- and three-dimensional environments.
abstract: Orientation of extracellular matrix (ECM) fibrils contributes to the anisotropy of bones, but little is known about how fibril orientation induces osteoblastic responses. Here, biomimetic polycaprolactone/type I collagen (PCL/COL-1) nanofibers with aligned and random fiber arrangements were used as models to study their effects on pre-osteoblasts. Elongated cell morphology, accelerated cell migration, elevated alkaline phosphatase activity and calcium content, up-regulated expression of osteogenic markers and differential expression of integrins were observed for cells cultured on two-dimensional (2D) aligned nanofibers. To emulate in vivo tissue structure, three-dimensional (3D) cell/nanofiber constructs with cells embedded among nanofiber layers were built via layer-by-layer assembly. These showed that aligned nanofibers in the 3D constructs continuously induced cell polarization and promoted osteogenesis. These findings revealed that nanofiber alignment favored osteogenic differentiation of pre-osteoblasts, and demonstrated the potential of 3D cell/nanofiber construct as a model to study specific cell-material interactions in a physiologically relevant environment.
  
  
  BACKGROUND
  In this novel study, biomimetic polycaprolactone/type I collagen nanofibers with aligned and random fiber arrangements were used to demonstrate their effects on pre-osteoblasts with an overall goal of improved orientation of extracellular matrix fibrils to optimize osteoblastic responses and improve osteogenesis for future therapeutic exploitation.
authors.affiliation: Chemistry, Chemical Biology and Biomedical Engineering, Stevens Institute of Technology, Hoboken, New Jersey, USA.
authors.forename: Xuening
authors.initials: X
authors.lastname: Chen
authors.forename: Xiaoling
authors.initials: X
authors.lastname: Fu
authors.forename: Jian-gang
authors.initials: JG
authors.lastname: Shi
authors.forename: Hongjun
authors.initials: H
authors.lastname: Wang
mesh_terms: D016475:3T3 Cells; D000818:Animals; D002454:Cell Differentiation; D049109:Cell Proliferation; D024042:Collagen Type I / Q000737:chemistry*; D005786:Gene Expression Regulation; D016023:Integrins / Q000235:genetics; D051379:Mice; D057139:Nanofibers / Q000737:chemistry / Q000648:ultrastructure*; D010006:Osteoblasts / Q000166:cytology* / Q000378:metabolism; D010012:Osteogenesis; D011091:Polyesters / Q000737:chemistry*; D023822:Tissue Engineering / Q000379:methods; D054457:Tissue Scaffolds / Q000737:chemistry*
chemical_list: D024042:Collagen Type I; D016023:Integrins; D011091:Polyesters; C016240:polycaprolactone
keywords: 3D culture; Electrospun nanofibers; Fiber orientation; Osteogenesis; Pre-osteoblasts