“Click” Chemistry-Mediated Phenylene-Cored Carborane Dendrimers

Abstract

Phenylene-cored small dendrimers containing three to nine peripheral o-carborane clusters were synthesized via Cu(I)-catalyzed Huisgen-type azide alkyne cycloaddition reactions. The resulting dendrimers have been characterized by IR and NMR spectroscopy and MALDI-TOF mass spectral analysis. The biological evaluation of branched dendrimer 16 containing nine carborane cages has been carried out using human liver cancer cells (SK-Hep1). Dendrimer 16 was accumulated in the SK-Hep1 cancer cells in a concentration-dependent manner. The highest boron accumulation up to 2540 ng of boron/5 × 105 cells was observed at a 50 μM concentration of 16 over a period of 20 h. The high accumulation of 16 into the tumor cell lines indicates that such dendritic boron drug delivery platforms could be possible for application in boron neutron capture therapy in cancer treatment.