Supercritical fluid-assisted controllable fabrication of open and highly interconnected porous scaffolds for bone tissue engineering

Sci China Life Sci. 2019 Dec;62(12):1670-1682. doi: 10.1007/s11427-018-9393-8. Epub 2019 Apr 16.

Abstract

Recently tremendous progress has been evidenced by the advancements in developing innovative three-dimensional (3D) scaffolds using various techniques for addressing the autogenous grafting of bone. In this work, we demonstrated the fabrication of porous polycaprolactone (PCL) scaffolds for osteogenic differentiation based on supercritical fluid-assisted hybrid processes of phase inversion and foaming. This eco-friendly process resulted in the highly porous biomimetic scaffolds with open and interconnected architectures. Initially, a 23 factorial experiment was designed for investigating the relative significance of various processing parameters and achieving better control over the porosity as well as the compressive mechanical properties of the scaffold. Then, single factor experiment was carried out to understand the effects of various processing parameters on the morphology of scaffolds. On the other hand, we encapsulated a growth factor, i.e., bone morphogenic protein-2 (BMP-2), as a model protein in these porous scaffolds for evaluating their osteogenic differentiation. In vitro investigations of growth factor loaded PCL scaffolds using bone marrow stromal cells (BMSCs) have shown that these growth factor-encumbered scaffolds were capable of differentiating the cells over the control experiments. Furthermore, the osteogenic differentiation was confirmed by measuring the cell proliferation, and alkaline phosphatase (ALP) activity, which were significantly higher demonstrating the active bone growth. Together, these results have suggested that the fabrication of growth factor-loaded porous scaffolds prepared by the eco-friendly hybrid processing efficiently promoted the osteogenic differentiation and may have a significant potential in bone tissue engineering.

Keywords: bone morphogenic protein-2; bone tissue engineering; osteogenic differentiation; polycaprolactone; supercritical foaming.

MeSH terms

  • Alkaline Phosphatase / metabolism
  • Animals
  • Bone Morphogenetic Protein 2 / metabolism
  • Bone and Bones / chemistry*
  • Bone and Bones / metabolism
  • Cell Adhesion
  • Cell Differentiation
  • Cell Proliferation
  • Compressive Strength
  • Humans
  • Mesenchymal Stem Cells / cytology
  • Mesenchymal Stem Cells / metabolism
  • Osteogenesis
  • Polyesters / chemistry*
  • Porosity
  • Printing, Three-Dimensional
  • Surface Properties
  • Tissue Engineering
  • Tissue Scaffolds / chemistry*

Substances

  • Bone Morphogenetic Protein 2
  • Polyesters
  • polycaprolactone
  • Alkaline Phosphatase