Abstract: The purpose of the present invention is to provide: a method for preparing a cell product for use in the production of an implant, which can improve the surface properties of a material by a simple technique and can integrate a bone with a metallic implant material satisfactorily within a given period of time; a product produced by the method; and a sophisticated implant produced using the product. A cell product containing Col-I, OCN, OPN, BSP, fibronectin and VEGF or another growth factor which are produced by a bone marrow stromal cell or an immortalized milk teeth stem cell is prepared from the bone marrow stromal cell or the immortalized milk teeth stem cell, and a sophisticated implant having the growth factor immobilized on the surface thereof is provided using the resultant cell product and a mineralizing solution.

Abstract: The purpose of the present invention is to provide immortalized stem cells, which produce a growth factor capable of regenerating various kinds of tissues that have been damaged by a variety of causes, and a method for producing the aforesaid immortalized stem cells. Another purpose of the present invention is to provide a medicinal composition and a medicinal preparation for restoring damaged tissues, and a method for the percutaneous absorption of a culture supernatant. Provided are immortalized stem cells that are obtained by isolating stem cells selected from the group consisting of mammalian mesenchymal cells, an embryo at the early stage of the development and somatic cells, first culturing the cells to give first stage culture cells, transferring four kinds of genes into the first stage culture cells to give transgenic cells, and selecting the desired immortalized stem cells from among the transgenic cells using the expression of STRO-1 as an index.