Fabrication and characterization of bioactive glass/alginate composite scaffolds by a self-crosslinking processing for bone regeneration

Abstract

The objective of this study was to synthesize and characterize self-crosslinked bioactive glass/alginate composite scaffolds, as a kind of potential biomaterial for bone regeneration. The scaffolds, fabricated through a self-crosslinking process of alginate by bioactive glass microspheres provided Ca²⁺ completely without any organic solvent, crosslinking agent, or binder. The microstructure, mechanical properties, apatite-forming ability, ionic release, adhesion, proliferation, and ALP activity of human bone marrow-derived mesenchymal stem cells (hBMSCs) of the scaffolds were evaluated. The results showed that uniform films could be obtained on the surface as well as in abundant crosslinking bridges in the interior of the scaffolds. The rapidly released Ca²⁺ from bioactive glass could be temporarily stored in alginate, which achieved the controlling release. The scaffolds, with porosities of 75–57%, had a compressive strength in the range of human trabecular bone. At the same time, they presented an excellent apatite formation ability in vitro. In vitro cellular study confirmed that the alginate films temporarily separated cells from bioactive glass which promoted early cell adhesion and all the groups showed good cell proliferation and ALP activity. All these results demonstrate that self-crosslinked scaffolds represent promising candidates for bone regeneration.