The toxicity and binding of the three new carborane based compounds: 2 (1,2-dicarba-closo-dodecaborane (12)-1(-yl-methoxy)-2-(3-amino-propyl))-1,3-propanediol, called
DAC-1; 7-(3-amino-propyl)-7,8-dicarba-nido-undecarborate (-1) called
ANC-1; and rac-1-(9-o-carboranyl)-nonyl-2-methyl-glycero-3-
phosphocholine, called
B-Et-11-OMe, were analyzed with cultured human
glioma cells, U-343MGa, and mouse
melanoma cells, B16, as
biological models. The previously developed compound di-
sodium undecahydro-mercapto-closo-dodecarborate (BSH), which is tested for
therapy of
malignant gliomas, was analyzed for comparison. In the toxicity tests the cells were exposed to the substances at cell culture medium concentrations in the range 0-50 ppm
boron for 1 or 20 h and thereafter analyzed regarding growth. Growth-disturbing effects were seen for the two compounds
DAC-1 and
B-Et-11-OMe at the concentrations corresponding to 15 and 50 ppm
boron, respectively. The compounds
ANC-1 and BSH showed no growth-disturbing effects at the tested concentrations. In the binding tests, the cells were incubated for 20 h at about the highest compound concentrations that did not cause growth disturbances. The
boron content in the cells was then determined by inductively coupled plasma-atomic emission spectrometry (ICP-AES) and in some cases ICP-mass spectrometry (ICP-MS). The most extensive binding was seen for
DAC-1 and
B-Et-11-OMe, which accumulated
boron to about 100 and 60 times, respectively, compared with the concentration in the culture medium. The compound
ANC-1 also accumulated
boron in the cells but the
boron could be easily washed out indicating no or only a weak binding. BSH did not accumulate. Further analysis should be made regarding
biological properties such as intracellular compartmentalization, metabolic interference and
tumor specificity of the compounds
DAC-1 and
B-Et-11-OMe.