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

The aim 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 were 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 abundant of crosslinking bridges in the interior of 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%, got 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 promoting early cell adhesion and all the groups showed good cell proliferation and ALP activity. All these results demonstrated that self-crosslinked scaffolds represented promising candidates for bone regeneration.