Improvement of tumor spheroid oxygenation by tetrachlorodecaoxide

The benefit of Tetrachlorodecaoxide (TCDO) in improving tumor tissue oxygenation has been tested using multicellular tumor spheroids. Measurements of oxygen tension (PO2) values with O2-sensitive microelectrodes revealed a distinct enhancement of the spheroid oxygenation after both, bolus injection or continuous infusion of TCDO into the medium surrounding the spheroids. The effect of TCDO on local oxygenation appeared to be less pronounced in spheroid regions with low initial PO2 values compared to well-oxygenated areas of these cellular aggregates. By continuously infusing TCDO into the measuring system, a sustained increase of local PO2 was obtained which was proportional to the local steady state concentration of TCDO in the medium surrounding the tumor spheroids. During experiments with TCDO in vivo, this substance should, therefore, be tested for its potential of improving the oxygenation status of solid tumors, and hence, of sensitizing tumors to classical treatments, such as radiotherapy.