Synthesis and characterization of hydroxyapatite–bacterial cellulose nanocomposites

Biocomposites consisting of hydroxyapatite (HAp) and natural polymers such as collagen, chitosan, chitin, and gelatin have been extensively investigated. However, studies on the combination of HAp with bacterial cellulose (BC) have not been conducted yet. In this work, our latest results concerning the biomimetic synthesis and characterization of HAp-BC nanocomposites with a 3-dimensional (3-D) network are reported. The present research focuses on characterizing the structure of this novel class of nanocomposites. Scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS), X-ray diffraction (XRD), and Fourier-transformed infrared spectroscopy (FTIR) were employed to characterize the HAp-BC nanocomposites. It is found that HAp crystals are formed when the phosphorylated and CaCl2-treated BC fibers are soaked in a 1.5 simulated body fluid (SBF). XRD reveals that the crystallite sizes of the HAp crystals are nano-sized and their crystallinities are low. The FTIR results show that the HAp crystals are partially substituted with carbonate, resembling natural bones. The nanocomposites containing HAp with structural features close to those of biological apatites are attractive for applications as artificial bones and scaffolds for tissue engineering.