Bio-inspired composite by hydroxyapatite mineralization on (bis)phosphonate-modified cellulose-alginate scaffold for bone tissue engineering

A novel three-dimensional composite scaffold was fabricated via a carefully designed strategy including preparation of a composite with components of cellulose as backbone and alginate as pore size expander, (bis)phosphonate-modification via oxidation with sodium periodate followed by Schiff-base reaction with sodium alendronate, and final biomimetic mineralization. The scaffolds possess appropriate porous structure and porosity. The chemical structure and morphology of the obtained composite scaffolds suggested that the deposited hydroxyapatite on the surface of the phosphorylated scaffolds was close to that of natural bone, including the content, crystallite size, crystallinity and Ca/P ratio. Moreover, it was also revealed that the scaffolds exhibited no cyto-toxicity and the cultured cells were well attached on the surface. Our investigation demonstrates that the presented (bis)phosphonate-modified cellulose/alginate/hydroxyapatite composite material is an appropriate candidate for the fabrication of scaffolds and has great potential to be applied to bone tissue engineering.