The effect of S53P4-based borosilicate glasses and glass dissolution products on the osteogenic commitment of human adipose stem cells

PLoS One. 2018 Aug 28;13(8):e0202740. doi: 10.1371/journal.pone.0202740. eCollection 2018.

Abstract

Despite the good performance of silicate bioactive glasses in bone regeneration, there is considerable potential to enhance their properties by chemical modifications. In this study, S53P4-based borosilicate glasses were synthesized and their dissolution profile was studied in simulated body fluid by assessing pH change, ion release and conversion to hydroxyapatite. The viability, proliferation, attachment, osteogenesis and endothelial marker expression of human adipose stem cells (hASCs) was evaluated upon direct culture on glass discs and in the extract medium. This is the first study evaluating cell behavior in response to borosilicate glasses based on S53P4 (commercially available as BonAlive®). Replacing silicate with borate in S53P4 increased the glass reactivity. Despite the good viability of hASCs under all conditions, direct culture of cells on borosilicate discs and in undiluted extract medium reduced cell proliferation. This was accompanied with changes in cell morphology. Regarding osteogenic commitment, alkaline phosphatase activity was significantly reduced by the borosilicate glass discs and extracts, whereas the expression of osteogenic markers RUNX2a, OSTERIX, DLX5 and OSTEOPONTIN was upregulated. There was also a borosilicate glass-induced increase in osteocalcin protein production. Moreover, osteogenic supplements containing borosilicate extracts significantly increased the mineral production in comparison to the osteogenic medium control. Interestingly, borosilicate glasses stimulated the expression of endothelial markers vWF and PECAM-1. To conclude, our results reveal that despite reducing hASC proliferation, S53P4-based borosilicate glasses and their dissolution products stimulate osteogenic commitment and upregulate endothelial markers, thus supporting their further evaluation for regenerative medicine.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adipose Tissue / cytology
  • Alkaline Phosphatase / metabolism
  • Boron / chemistry
  • Cell Culture Techniques / instrumentation*
  • Cell Culture Techniques / methods
  • Cell Differentiation / drug effects*
  • Cell Proliferation / drug effects
  • Cells, Cultured
  • Core Binding Factor Alpha 1 Subunit / genetics
  • Core Binding Factor Alpha 1 Subunit / metabolism
  • Glass / chemistry*
  • Humans
  • Osteogenesis / drug effects*
  • Osteopontin / genetics
  • Osteopontin / metabolism
  • Platelet Endothelial Cell Adhesion Molecule-1 / genetics
  • Platelet Endothelial Cell Adhesion Molecule-1 / metabolism
  • Silicates / chemistry
  • Silicates / pharmacology*
  • Stem Cells / cytology
  • Stem Cells / drug effects
  • Stem Cells / metabolism
  • Up-Regulation / drug effects

Substances

  • Core Binding Factor Alpha 1 Subunit
  • Platelet Endothelial Cell Adhesion Molecule-1
  • Silicates
  • Osteopontin
  • Alkaline Phosphatase
  • Boron

Grants and funding

This study was supported by TEKES, the Finnish Funding Agency for Innovation (https://www.businessfinland.fi/en/), Academy of Finland (grant number #275427; http://www.aka.fi/en), Jane and Aatos Erkko Foundation (https://jaes.fi/en/), the Competitive State Research Financing of the Expert Responsibility area of Tampere University Hospital (http://www.pshp.fi/en-US/Hospital_District), and the Doctoral Programme in Biomedicine and Biotechnology (http://www.uta.fi/med/en/MED_doctoral_programme.html). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.