C 60 -β-cyclodextrin conjugates for enhanced nucleus delivery of doxorubicin.

We demonstrate the use of water-soluble C 60 -β-cyclodextrin conjugates to encapsulate and deliver doxorubicin to the cell nucleus. The behaviour of the fullerene aggregates inside cells is dictated by the functionalization of the C 60 cage. While both the C 60 conjugates are taken up by lysosomes upon cellular entry, only the one with a hydroxylated cage rapidly escaped the lysosome. The drug delivery system (DDS) with a hydroxylated C 60 cage showed significantly enhanced doxorubicin delivery to the cell nucleus, whereas the DDS with a hydrophobic C 60 cage was trapped in the lysosome for a longer time and showed significantly reduced doxorubicin delivery to the nucleus. This study opens new paths towards advanced fullerene-based DDSs for small molecule drugs.