Biological responses of MC3T3-E1 on calcium carbonate coatings fabricated by hydrothermal reaction on titanium

Titainum (Ti) implants have been successfully used in orthopaedic and dental surgery. However, the poor early bone tissue integration is still a common failure. This could be modulated by improving material bonding or adhesion directly to bone though a surface roughening and/or a bioresorbable and osteoconductive coating. In this study, we report on the biological behavious of the Ti substrate with modified surface roughness and/or bioactive coating. The roughened Ti surface was prepared by acid etching reaction, and the calcium carbonate (CaCO3) coating on the substrates was synthesized by hydrothermal treatment of Ti in calcium citrate complexes. The study demonstrated that surface roughing of Ti alone did not improve the biological reponse of the MC3T3-E1 cells, however, CaCO3 coating on smooth Ti surface increased cell responses, and the affects were further enhanced in combination with Ti surface roughening. Larger cell area, greater cell proliferation and increased bone-like nodule formation were obtained on the CaCO3 coating of the roughened Ti surface. This was also supported by a higher ALP value obtained for the the coatings of roughened Ti surface. The cell behaviours found in the current study support further development of calcium carbonate coatings towards clinical application.