The cytotoxicity of metal-encapsulating carbon nanocapsules

The toxicity of carbon nanoparticles has been studied using both in vivo and in vito techniques as well as the cytotoxicity of metal-encapsulating carbon nanocapsules (MECNC) were investigated. MECNCs are several tens of nanometers in diameter and consist of a metallic carbide encapsulated within a graphene sheet, which imbues upon the nanocapsules a reasonably high chemical stability. The toxicity of MECNCs was estimated using rat fibroblasts and macrophages under various concentrations. The yield of MECNC was roughly estimated to be about 30% from the TEM observations. It was also observed that the concentration dependence of cell viability and LDH release were in good coordination with each other. MECNCs stably encapsulate lanthanum carbides, which are unstable and easily oxidized in air. This demonstrates the low defect levels and therefore, the highly the air-tight character of the graphene sheet capsules of MECNCs.