Effect of bioglass on growth and biomineralization of SaOS-2 cells in hydrogel after 3D cell bioprinting

PLoS One. 2014 Nov 10;9(11):e112497. doi: 10.1371/journal.pone.0112497. eCollection 2014.

Abstract

We investigated the effect of bioglass (bioactive glass) on growth and mineralization of bone-related SaOS-2 cells, encapsulated into a printable and biodegradable alginate/gelatine hydrogel. The hydrogel was supplemented either with polyphosphate (polyP), administered as polyP • Ca2+-complex, or silica, or as biosilica that had been enzymatically prepared from ortho-silicate by silicatein. These hydrogels, together with SaOS-2 cells, were bioprinted to computer-designed scaffolds. The results revealed that bioglass (nano)particles, with a size of 55 nm and a molar ratio of SiO2 : CaO : P2O5 of 55 : 40 : 5, did not affect the growth of the encapsulated cells. If silica, biosilica, or polyP • Ca2+-complex is co-added to the cell-containing alginate/gelatin hydrogel the growth behavior of the cells is not changed. Addition of 5 mg/ml of bioglass particles to this hydrogel significantly enhanced the potency of the entrapped SaOS-2 cells to mineralize. If compared with the extent of the cells to form mineral deposits in the absence of bioglass, the cells exposed to bioglass together with 100 µmoles/L polyP • Ca2+-complex increased their mineralization activity from 2.1- to 3.9-fold, or with 50 µmoles/L silica from 1.8- to 2.9-fold, or with 50 µmoles/L biosilica from 2.7- to 4.8-fold or with the two components together (100 µmoles/L polyP • Ca2+-complex and 50 µmoles/L biosilica) from 4.1- to 6.8-fold. Element analysis by EDX spectrometry of the mineral nodules formed by SaOS-2 revealed an accumulation of O, P, Ca and C, indicating that the mineral deposits contain, besides Ca-phosphate also Ca-carbonate. The results show that bioglass added to alginate/gelatin hydrogel increases the proliferation and mineralization of bioprinted SaOS-2 cells. We conclude that the development of cell-containing scaffolds consisting of a bioprintable, solid and cell-compatible inner matrix surrounded by a printable hard and flexible outer matrix containing bioglass, provide a suitable strategy for the fabrication of morphogenetically active and biodegradable implants.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Alginates / chemistry
  • Biocompatible Materials / chemistry*
  • Bioprinting / methods*
  • Bone Development
  • Calcification, Physiologic
  • Cell Line
  • Cell Proliferation
  • Ceramics / chemistry*
  • Gelatin / chemistry
  • Humans
  • Hydrogel, Polyethylene Glycol Dimethacrylate / chemistry*
  • Nanoparticles / chemistry
  • Particle Size
  • Tissue Engineering / methods
  • Tissue Scaffolds / chemistry*

Substances

  • Alginates
  • Biocompatible Materials
  • Bioglass
  • Hydrogel, Polyethylene Glycol Dimethacrylate
  • Gelatin

Grants and funding

WEGM is a holder of an ERC Advanced Investigator Grant (No. 268476 BIOSILICA). This work was supported by grants from the Deutsche Forschungsgemeinschaft (Schr 277/10-3), the European Commission (Industry-Academia Partnerships and Pathways “CoreShell”: No. 286059; “Bio-Scaffolds”: No. 604036; “MarBioTec*EU-CN*”: No. 268476; and “BlueGenics”: No. 311848) and the International Human Frontier Science Program. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript. NanotecMARIN GmbH provided support in the form of salary for author BDS, but did not have any additional role in the study design, data collection and analysis, decision to publish, or preparation of the manuscript. The specific role of this author is articulated in the ‘author contributions’ section.