Photochemical purging of autologous bone marrow grafts: assessment of damage to stem cells and the microenvironment in long-term marrow cultures

Abstract

Toxicity of merocyanine 540 (MC540) was assessed in long-term (Dexter-type) bone marrow cultures and in a short-term in vitro clonal assay of fibroblast colony-forming cells (CFU-F). Exposure of freshly explanted mouse bone marrow cells to MC540 (15 μ g/ml) and white light (fluence: 126 kJ/m²) reduced CFU-F by approximately 2 logs but did not abrogate the cells’ capacity to establish and maintain long-term bone marrow cultures. Fat cells were rare or absent in adherent layers established with photosensitized bone marrow cells but the cultures’ capacity to generate non-adherent cells, granulocyte/macrophage progenitors (CFU-GM), and early erythroid progenitors (BFU-E) was only moderately (28–36%) reduced.