The invention relates to an in-vitro and in-vivo method for multiplying and differentiating cells, during which the growth process of the cells is initiated or terminated and structurally directed by the use of growth factors thrombopoietin (TPO) and/or erythropoietin (EPO), and/or growth hormone (GH), particularly human growth hormone (HGH), and/or somatostatin and/or leukemia inhibitor factor (LHF) and/or ciliary neurotropic factor (CNTF). The invention relates to a biological matrix or supporting structure containing the aforementioned growth factors, and to a method and device for the production thereof and for carrying out the inventive method.
