Needle-like ion-doped hydroxyapatite crystals influence osteogenic properties of PCL composite scaffolds

V. Guarino, F. Veronesi, M. Marrese, G. Giavaresi, A. Ronca, M. Sandri, A. Tampieri, M. Fini, Luigi Ambrosio

Research output: Contribution to journalArticle

10 Scopus citations

Abstract

Surface topography and chemistry both play a crucial role on influencing cell response in 3D porous scaffolds in terms of osteogenesis. Inorganic materials with peculiar morphology and chemical functionalities may be proficiently used to improve scaffold properties - in the bulk and along pore surface - promoting in vitro and in vivo osseous tissue in-growth. The present study is aimed at investigating how bone regenerative properties of composite scaffolds made of poly(ε-caprolactone) (PCL) can be augmented by the peculiar properties of Mg2+ ion doped hydroxyapatite (dHA) crystals, mainly emphasizing the role of crystal shape on cell activities mediated by microstructural properties. At the first stage, the study of mechanical response by crossing experimental compression tests and theoretical simulation via empirical models, allow recognizing a significant contribution of dHA shape factor on scaffold elastic moduli variation as a function of the relative volume fraction. Secondly, the peculiar needle-like shape of dHA crystals also influences microscopic (i.e. crystallinity, adhesion forces) and macroscopic (i.e. roughness) properties with relevant effects on biological response of the composite scaffold: differential scanning calorimetry (DSC) analyses clearly indicate a reduction of crystallization heat - from 66.75 to 43.05 J g-1 - while atomic force microscopy (AFM) ones show a significant increase of roughness - from (78.15 ± 32.71) to (136.13 ± 63.21) nm - and of pull-off forces - from 33.7% to 48.7%. Accordingly, experimental studies with MG-63 osteoblast-like cells show a more efficient in vitro secretion of alkaline phosphatase (ALP) and collagen I and a more copious in vivo formation of new bone trabeculae, thus suggesting a relevant role of dHA to support the main mechanisms involved in bone regeneration.

Original languageEnglish (US)
Article number015018
JournalBiomedical Materials (Bristol)
Volume11
Issue number1
DOIs
StatePublished - Feb 29 2016

Keywords

  • composite scaffolds
  • in vivo studies
  • ion doping
  • mechanical properties
  • needle-like hydroxyapatite

ASJC Scopus subject areas

  • Bioengineering
  • Biomaterials
  • Biomedical Engineering

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