The study population will consist of a total of 60 diabetic patients with chronic critical ischemia of one leg (CLI) and no possibility of revascularization. In the experimental group will include a total of 45 patients divided into three dose levels, 15 patients in each level (increasing doses of mononuclear cells of bone marrow evenly) and 15 patients in control group (no cell therapy). Patients will be randomly assigned to either the control group or to any of the three experimental groups in which the dose of mononuclear cells of bone marrowo will be: