The preparation and characteristics of a carbonated hydroxyapatite/collagen composite at room temperature

Nanocarbonated hydroxyapatite/collagen (nCHAC) composite was prepared at room temperature via biomimetic self-assembly method. X-ray diffraction (XRD), thermogravimetric analysis (TGA), and transmission electron microscopy (TEM) were performed. This composite shows the same inorganic phase of natural bone with nanosized level and low degree of crystallinity, and contains 2.8-14.7 wt % of carbonated content. TEM results confirm that the microstructure of this composite is the mineralized collagen fiber bundle like the hierarchical structure of natural bone. The diameter of a single mineralized collagen fiber is about 4 nm. Slightly different assembly units of the composite with different carbonates and collagen were demonstrated. The carbonated percentage affects the mineral crystal size and collagen fibril assembly. Because of the biomimetic component and microstructure, the use of nCHAC composite is promising for hard tissue therapy.