Organically modified hydroxyapatite (ormoHAP) nanospheres stimulate the differentiation of osteoblast and osteoclast precursors: a co-culture study

Biomed Mater. 2019 Apr 15;14(3):035015. doi: 10.1088/1748-605X/ab0fad.

Abstract

Isolated nanospheres consisting of organically modified hydroxyapatite (ormoHAP), prepared by an electric field-assisted ion double migration process, were embedded in foamed gelatin to form a composite scaffold. Degradation rates have been demonstrated to correlate with the crosslinking degree (40%, 80%) as well as with the mineral content of the scaffolds (0%, 20%, 40%). A human co-culture model of osteoblasts and osteoclasts, derived from bone marrow stromal cells and monocytes, respectively, without external addition of the factors RANKL and M-CSF, was run for up to 42 d in order to characterize the action of the ormoHAP-gelatin scaffolds on the co-culture. Examination was performed by quantitative biochemical methods (DNA, LDH, ALP, TRAP5b), gene expression analysis (ALP, BSP II, RANKL, IL-6, VTNR, CTSK, TRAP, OSCAR, CALCR) and confocal laser scanning microscopy (cell nuclei, actin, CD68, TRAP). Results confirm that ormoHAP embedded in the gelatin matrix enhanced TRAP 5b activity. As a feedback, ALP activity and gene expression of BSP II of osteoblasts increased. Finally, a sequence of cell cross-talk actions is suggested, which can explain the behavior of the formed vital co-culture and moreover the influence of the presence and concentration of ormoHAP.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Alkaline Phosphatase / metabolism
  • Bone Marrow Cells / cytology
  • Cell Differentiation
  • Coculture Techniques
  • DNA / chemistry
  • Durapatite / chemistry*
  • Gelatin / chemistry
  • Gene Expression Profiling
  • Humans
  • Image Processing, Computer-Assisted
  • Ions
  • Mesenchymal Stem Cells / cytology
  • Monocytes / cytology
  • Nanospheres / chemistry*
  • Osteoblasts / cytology*
  • Osteoclasts / cytology*
  • Osteocytes / cytology
  • Tissue Scaffolds

Substances

  • Ions
  • Gelatin
  • DNA
  • Durapatite
  • Alkaline Phosphatase