Amorphous inorganic polyphosphate-calcium-phosphate particles inducing bone formation

摘要

A method for the preparation of biologically active amorphous polyphosphate-substituted calcium phosphate particles (aCaP-polyP) comprises: (a) adding an aqueous solution of a polyphosphate salt to an aqueous solution of a phosphate source; (b) addition of the resulting solution to a dissolved calcium sa (c) adjusting the pH to an alkaline value, preferably 10; and (d) collecting, washing and drying of the resulting precipitate formed after several hours, preferably at room temperature after 24hrs. The amount of polyphosphate salt may be higher than 5wt.%, more preferably 10wt.%, with respect to the calcium phosphate preparation. The calcium salt may be calcium chloride, and the phosphate source may be ammonium phosphate dibasic. The amount of reagents may be calculated in order to obtain the Ca/P molar ratio for the calcium phosphate of 10:6. Preferably, the chain length of the polyphosphate is in the range of 3 to 1000, preferably 40. The amorphous hybrid polyP-CaP particles formed cause up-regulation of the expression of marker genes encoding for proteins related to bone formation (collagen type I and alkaline phosphatase), and may be of use in artificial bone implants.