The influence of Sr content in calcium phosphate coatings

• Calcium phosphate coating doping with low Sr contents was prepared via a biomineralization process.
• The solubility of the coatings increased with increased Sr concentration.
• Present findings show the potential that Sr has on promoting osteogenic differentiation even in a low amount.

In this study calcium phosphate coatings with different amounts of strontium (Sr) were prepared using a biomineralization method. The incorporation of Sr changed the composition and morphology of coatings from plate-like to sphere-like morphology. Dissolution testing indicated that the solubility of the coatings increased with increased Sr concentration. Evaluation of extracts (with Sr concentrations ranging from 0 to 2.37 μg/mL) from the HA, 0.06Sr, 0.6Sr, and 1.2Sr coatings during in vitro cell cultures showed that Sr incorporation into coatings significantly enhanced the ALP activity in comparison to cells treated with control and HA eluted media. These findings show that calcium phosphate coatings could promote osteogenic differentiation even in a low amount of strontium.