Safety Study of Autologous Bone Marrow Stromal Cells With Modification by Hepatocyte Growth Factor to Treat Silicosis

Inclusion Criteria: \- age between 18-50, chronic and accelerated silicosis, characterized with a fibrotic increase in the last two years, FEV1 \<60% and \> 40%, FVC \> 60% and SaO2 \>90% Exclusion Criteria: \- smoking, active tuberculosis or other infections, cancer, auto-immune disorders, hematological, hepatic or cardiac diseases, and pregnancy