Bioactivity evaluation of novel nanocomposite scaffolds for bone tissue engineering: The impact of hydroxyapatite

The objective of this study was to prepare scaffolds based on cellulose-graft-polyacrylamide composed of different contents of nano-hydroxyapatite (n-HAp). To this end, polyacrylamide was grafted onto cellulose in the presence of n-HAp through free radical polymerization. Then, the scaffolds of the dispersed grafted polymer nanocomposite powder were fabricated by the freeze-drying method. The grafted polymer nanocomposite scaffolds were tested and characterized using tensile test instrument, Fourier transform infrared (FTIR) spectroscopy, scanning electron microscopy (SEM), and X-ray diffraction (XRD) analysis. Finally, bioactivity and apatite formation on the surface after immersion in a simulated body fluid (SBF) were determined by XRD and SEM analysis. According to the results, as the n-HAp content in the scaffold structure increased, the porosity, elastic modulus and compressive strength were increased. In addition, apatite was deposited very well on the interconnected irregular pores on the surface of the scaffolds after incubation in SBF, while the size of precipitated apatite was reduced by increasing the soaking time. The results indicated that the prepared grafted polymer nanocomposite scaffolds have a great potential as biocompatible materials for use in bone tissue engineering. (C) 2016 Elsevier Ltd and Techna Group S.r.l. All rights reserved.