3D bioprinting of methacrylated hyaluronic acid (MeHA) hydrogel with intrinsic osteogenicity

PLoS One. 2017 Jun 6;12(6):e0177628. doi: 10.1371/journal.pone.0177628. eCollection 2017.

Abstract

In bone regenerative medicine there is a need for suitable bone substitutes. Hydrogels have excellent biocompatible and biodegradable characteristics, but their visco-elastic properties limit their applicability, especially with respect to 3D bioprinting. In this study, we modified the naturally occurring extracellular matrix glycosaminoglycan hyaluronic acid (HA), in order to yield photo-crosslinkable hydrogels with increased mechanical stiffness and long-term stability, and with minimal decrease in cytocompatibility. Application of these tailor-made methacrylated hyaluronic acid (MeHA) gels for bone tissue engineering and 3D bioprinting was the subject of investigation. Visco-elastic properties of MeHA gels, measured by rheology and dynamic mechanical analysis, showed that irradiation of the hydrogels with UV light led to increased storage moduli and elastic moduli, indicating increasing gel rigidity. Subsequently, human bone marrow derived mesenchymal stromal cells (MSCs) were incorporated into MeHA hydrogels, and cell viability remained 64.4% after 21 days of culture. Osteogenic differentiation of MSCs occurred spontaneously in hydrogels with high concentrations of MeHA polymer, in absence of additional osteogenic stimuli. Addition of bone morphogenetic protein-2 (BMP-2) to the culture medium further increased osteogenic differentiation, as evidenced by increased matrix mineralisation. MeHA hydrogels demonstrated to be suitable for 3D bioprinting, and were printed into porous and anatomically shaped scaffolds. Taken together, photosensitive MeHA-based hydrogels fulfilled our criteria for cellular bioprinted bone constructs within a narrow window of concentration.

MeSH terms

  • Bioprinting*
  • Bone Regeneration
  • Cell Differentiation / drug effects
  • Cell Survival / drug effects
  • Cells, Cultured / drug effects
  • Glycosaminoglycans / chemical synthesis
  • Glycosaminoglycans / chemistry
  • Glycosaminoglycans / pharmacology
  • Humans
  • Hyaluronic Acid / chemical synthesis
  • Hyaluronic Acid / chemistry
  • Hyaluronic Acid / pharmacology
  • Hydrogel, Polyethylene Glycol Dimethacrylate / chemical synthesis
  • Hydrogel, Polyethylene Glycol Dimethacrylate / chemistry
  • Hydrogel, Polyethylene Glycol Dimethacrylate / pharmacology*
  • Mesenchymal Stem Cells / drug effects*
  • Osteogenesis / drug effects*
  • Polymethacrylic Acids / chemical synthesis
  • Polymethacrylic Acids / chemistry
  • Polymethacrylic Acids / pharmacology
  • Rheology
  • Tissue Engineering
  • Tissue Scaffolds

Substances

  • Glycosaminoglycans
  • Polymethacrylic Acids
  • Hydrogel, Polyethylene Glycol Dimethacrylate
  • Hyaluronic Acid

Grants and funding

MP: This research forms part of the Project P2.04 BONE-IP of the research program of the BioMedical Materials institute, co-funded by the Dutch Ministry of Economic Affairs. Funding sources had no role in study design, data collection and analysis or data interpretation. JA was supported by the Dutch Arthritis Foundation.