Abstract: The combination of a phosphatase enzyme with a biocompatible carrier material produces materials which are useful in the repair of the skeleton and the promotion of new bone growth. The combination preferably involves covalent coupling between the enzyme and the carrier. The preferred carrier materials include fibrillar collagen and may be obtained by the demineralization of calcified tissues. The materials may include phosphoproteins or dentinal phosphophoryns which may be residual or may be added during the preparation of the materials. The incorporation of other organophosphates and inorganic phosphates may improve the rate of mineralization especially in older animals.