Toxicity analysis of various Pluronic F-68-coated carbon nanotubes on mesenchymal stem cells

• Pluronic F-68 enhanced dispersibility and biosafety of MWCNTs.
• PF68/MWCNTs didn't affect cell-surface markers and biodistribution of MSCs.
• PF68 can reduce the acute toxicity of MWCNTs but not alter their biological fate.

Carbon nanotubes (CNTs) have poor colloid stability in biological media and exert cytotoxic effects on mesenchymal stem cells (MSCs). Modification with polymeric surfactant is a widely used strategy to enhance water dispersibility of CNTs. This study investigated the toxic effects of various Pluronic F-68 (PF68)-coated multi-walled CNTs (MWCNTs) on rat bone marrow-derived MSCs.PF68-coated MWCNTs showed favorable biocompatibility to MSCs that the cell viability, apoptosis, and reactive oxygen species (ROS) were not altered after 24 h of co-incubation. Nevertheless, significant apoptosis induction and massive ROS release were found following extended exposure (48 and 72 h), and the toxic impact was dependent on the initial surface properties of the encapsulated MWCNTs. All the types of PF68-coated MWCNTs did not affect the cell-surface markers and in vivo biodistribution of MSCs. Our results suggest that proper polymer coating can reduce the acute toxicity of MWCNTs to MSCs but without altering their biological fate.