title: Osteoclastogenic differentiation of human precursor cells over micro- and nanostructured hydroxyapatite topography.
abstract: BACKGROUND
  Surface topography is a key parameter in bone cells-biomaterials interactions. This study analyzed the behavior of human osteoclast precursor cells cultured over three hydroxyapatite (HA) surfaces ranging from a micro- to nanoscale topography.
  
  
  METHODS
  HA surfaces were prepared with microsized HA particles, at 1300°C (HA1), and with nanosized HA particles at 1000°C (HA2) and 830°C (HA3). Human osteoclast precursors were cultured in the absence or presence of M-SCF and RANKL.
  
  
  RESULTS
  HA surfaces had similar chemical composition, however, HA1 and HA3 presented typical micro- and nanostructured topographies, respectively, and HA2 profile was between those of HA1 and HA3. The decrease on the average grain diameter to the nanoscale range (HA3) was accompanied by an increase in surface area, porosity and hydrophilicity and a decrease in roughness. Compared to HA1 surface, HA3 allowed a lower osteoclastic adhesion, differentiation and function. Differences in the cell response appeared to be associated with the modulation of relevant intracellular signaling pathways.
  
  
  CONCLUSIONS
  The decrease in HA grain size to a biomimetic nanoscale range, appears less attractive to osteoclastic differentiation and function, compared to the HA microsized topography.
  
  
  CONCLUSIONS
  This observation emphasizes the role of surface topography in designing advanced biomaterials for tailored bone cells response in regenerative strategies.
authors.affiliation: Laboratory for Bone Metabolism and Regeneration, Faculty of Dental Medicine, University of Porto, Portugal; ESTSP - Escola Superior de Tecnologia da Saúde do Porto, Instituto Politécnico do Porto, Portugal. Electronic address: jrodrigues@fmd.up.pt.
authors.forename: J
authors.initials: J
authors.lastname: Costa-Rodrigues
authors.affiliation: Laboratory for Bone Metabolism and Regeneration, Faculty of Dental Medicine, University of Porto, Portugal; Departamento de Engenharia Metalúrgica e de Materiais, Faculdade de Engenharia, Universidade do Porto, Portugal.
authors.forename: S
authors.initials: S
authors.lastname: Carmo
authors.affiliation: Rheumatology Research Unit, Instituto de Medicina Molecular, Lisbon Academical Medical Centre, Lisbon, Portugal.
authors.forename: I P
authors.initials: IP
authors.lastname: Perpétuo
authors.affiliation: Departamento de Engenharia Metalúrgica e de Materiais, Faculdade de Engenharia, Universidade do Porto, Portugal; INEB - Instituto de Engenharia Biomédica, Universidade do Porto, Portugal.
authors.forename: F J
authors.initials: FJ
authors.lastname: Monteiro
authors.affiliation: Laboratory for Bone Metabolism and Regeneration, Faculty of Dental Medicine, University of Porto, Portugal.
authors.forename: M H
authors.initials: MH
authors.lastname: Fernandes
mesh_terms: D000328:Adult; D001672:Biocompatible Materials / Q000737:chemistry / Q000494:pharmacology*; D002454:Cell Differentiation / Q000187:drug effects*; D017886:Durapatite / Q000737:chemistry / Q000494:pharmacology*; D005260:Female; D006801:Humans; D008297:Male; D010010:Osteoclasts / Q000166:cytology / Q000378:metabolism*; D015398:Signal Transduction / Q000187:drug effects*; D013234:Stem Cells / Q000166:cytology / Q000378:metabolism*; D013499:Surface Properties
chemical_list: D001672:Biocompatible Materials; D017886:Durapatite
keywords: Hydroxyapatite; Microtopography; Nanotopography; Osteoclastogenesis