The influence of transition metal ions on collagen mineralization

The ions in body fluid play an important role in bone formation besides being a synthesizing material. Transition metal ions Co2+, Ni2+, Zn2+, Fe3+, Mn2+, Cu2+, Cd2+ and Hg2+ doped hydroxyapatite (HAP)/collagen composites were synthesized successfully in the presence of collagen traces at mild acidic pH for the first time. However, the amount of doped Hg2+ and Cd2+ was relatively low. Meanwhile, through soaking the collagen sponge as a template in simulated body fluid (SBF) which contains different transition metal ions (Mn2+, Cu2+, Ni2+, Co2+, Cd2+, Hg2+), bone-like HAP/collagen composites were synthesized. Hg2+ had a certain inhibitory effect on the formation of HAP crystals on the surface of the collagen sponge while Co2+ can promote the formation of HAP on the collagen sponge. For both HAP/collagen composites and HAP/collagen sponge, it was found that transition metal ions Mn2+ had a significant effect on the morphology of HAP particles and could induce to form floc-like HAP particle aggregates. (C) 2013 Elsevier B.V. All rights reserved.