Bioactive alginate/carrageenan/calcium silicate porous scaffolds for bone tissue engineering

Abstract

Porous bioactive alginate/carrageenan/calcium silicate scaffolds for bone tissue engineering were fabricated. The scaffolds were prepared by dispersing the synthesized calcium silicate in an aqueous solution of alginate and carrageenan at 90 °C. The scaffolds were shaped by freeze-drying and further crosslinked by 0.5, 1.0 and 1.5 M CaCl2 for 60 and 120 min. The scaffolds crosslinked by 1.5 M CaCl2 for 120 min achieved the highest in vitro dimension stability. The formation of hydroxyapatite crystals was observed on the scaffolds surface after soaking in simulated body fluid (SBF) at 37 °C for 7–28 days, indicating in vitro bioactivity of the scaffolds. The presence of calcium silicate could enhance not only the bioactivity, but also the mechanical properties of the scaffolds comparable to the cancellous bone. Moreover, the dimension and mechanical properties of the wet scaffolds could recover to the original after four cycles of mechanical testing at 50 % strain. The scaffolds were nontoxic to human living cells, in which the in vitro drug release behavior of the scaffold using diclofenac as a model drug was suitable for the treatment of acute inflammation after surgery. Therefore, these scaffolds were considered to be the candidate materials for bone replacement.