Efficient tailoring of platinum nanoparticles supported on multiwalled carbon nanotubes for cancer therapy.

Therapeutically targeting cancer stem cells (CSCs), which play a role in tumor initiation and relapse, remains challenging. Novel-formulated platinum nanoparticles (Pt-NPs) supported on polybenzimidazole (PBI)-functionalized polymers and multiwalled carbon nanotubes (MWCNT) were prepared and their effect on CSCs was evaluated. Pt-NPs showed homogenous distribution on the surface of MWCNT/PBI composites, with very narrow particle size. MWCNT/PBI/Pt-NPs resulted in a dramatic decrease in the proliferation rate of CSCs but not bone marrow mesenchymal stem cells (BM-MSCs). Quantitative gene expression analysis revealed that MWCNT/PBI/Pt had a significant inhibitory effect on the epithelial-mesenchymal transition and cell cycle markers of CSCs. MWCNT/PBI/Pt exhibited a specific cytotoxic effect on breast CSCs but not on adult stem cells.