A method for the preparation of morphogenetically active amorphous strontium-polyphosphate nanoparticles or microparticles ("Sr-a-polyP-MP") comprises: (a) dissolving sodium polyphosphate in an aqueous medium, such as distilled water, and adjustment to about pH10 with a basic aqueous solution, such as sodium hydroxide； (b) dissolving of a strontium salt in a suitable aqueous medium, such as aqueous ethanol； (c) slow (e.g. dropwise) addition of the polyphosphate solution to the strontium salt solution, keeping the pH at about 10 with a basic aqueous solution, such as sodium hydroxide, (d) forming particles, preferably by stirring of the suspension overnight at room temperature； and (e) collecting the particles, preferably by filtration, and washing with an aqueous medium, e.g. aqueous ethanol, and drying. The strontium polyphosphate particles may be encapsulated into acid-resistant capsules for oral administration. The microparticles or nanoparticles may be embedded into microspheres of poly(D,L)-lactide-co-glycolide (PLGA). The strontium nanoparticles or microparticles may be used in a method of preventing or treating bone-related diseases such as osteoporosis, and also in bone repair.
