Immobilization of calcium and phosphate ions improves the osteoconductivity of titanium implants

Mater Sci Eng C Mater Biol Appl. 2016 Nov 1;68:291-298. doi: 10.1016/j.msec.2016.05.090. Epub 2016 May 24.


In this work, to elevate weak osteoconductivity of titanium (Ti) implant, we prepared a Ti implant having both calcium and phosphate ions on its surface. To modify calcium and phosphate ions onto Ti, phosphate ions were first immobilized by treating the Ti with a NaH2PO4 solution, followed by CaCl2 treatment to immobilize calcium ions, which created the calcium and phosphate ions-modified Ti (Ca-P-Ti). X-ray photoelectron spectroscopy and thin-layer X-ray diffraction measurement confirmed that both phosphate and calcium ions were co-immobilized onto the Ti surface on the molecular level. Three-hour after seeding MC3T3-E1 murine pre-osteoblast cells on substrates, cell number on Ca-P-Ti was much larger than that of Ti and phosphate-modified Ti (P-Ti), but was similar to that of calcium-modified Ti (Ca-Ti). Also, MC3T3-E1 cells on Ca-P-Ti expressed larger amount of vinculin, a focal adhesion protein, than those on other substrates, probably resulting in larger cell size as well as greater cell proliferation on Ca-P-Ti than those on other substrates. Alkaline phosphatase activity of cells on Ca-P-Ti was greater than those on Ti and P-Ti, but was almost comparable to that of Ca-Ti. Moreover, the largest amount of bone-like nodule formation was observed on Ca-P-Ti. These results provide evidence that calcium and phosphate ions-co-immobilization onto Ti increased the osteoconductivity of Ti by stimulating the responses of pre-osteoblast cells. This simple modification would be promising technique for bone tissue implant including dental and orthopedic implants.

Keywords: Calcium ions; Osteoconductive surface; Phosphate ions; Titanium implant.

MeSH terms

  • Animals
  • Calcium* / chemistry
  • Calcium* / pharmacokinetics
  • Calcium* / pharmacology
  • Coated Materials, Biocompatible* / chemistry
  • Coated Materials, Biocompatible* / pharmacokinetics
  • Coated Materials, Biocompatible* / pharmacology
  • Mice
  • Osteoblasts / metabolism*
  • Osteogenesis / drug effects*
  • Phosphates* / chemistry
  • Phosphates* / pharmacokinetics
  • Phosphates* / pharmacology
  • Titanium* / chemistry
  • Titanium* / pharmacokinetics
  • Titanium* / pharmacology


  • Coated Materials, Biocompatible
  • Phosphates
  • Titanium
  • Calcium