Silvia Giordani: Carbon nano-onions for biomedical applications

Carbon nano-onions (CNOs) will be discussed as a potentiel vesicle for nanocarrier-type drug delivery systems. CNOs, or multi-layer fullerenes, consist of multiple concentric loyers of sp2 hybridized carbon and are emerging as platforms for biomedical applications because of their ability to be internalized by cells and low toxicity.

In my research group we have developed methodology for the synthesis of pure, monodispersed CNOs and various Chemical functionalization strategies for the introduction of different functionalities (receptor targeting unit and imaging unit) onto the surface of the CNOs. Supramolecular functionalization with biocompatible polymers is an effective strategy to engineer drug carriers for targeted delivery applications. We reported the use of a hyaluronic acidphospholipid (HA-DMPE) conjugale to target CD44 overexpressing cancer cells, while enhancing solubility of the nanoconstruct. Non-covalently functionalized CNOs with HADMPE show excellent in vitro cell viability in human breast carcinoma cells overexpressing CD44 and are uptaken to a greater extent compared to human ovarian carcinoma cells with an undetectable amount of CD44. In addition, they possess high in vivo biocompatibility in zebrafish during the different stages of development suggesting a high degree of biosafety of this class of nanomaterials.

Our results encouraged us to further develop them as targeted diagnostics or therapeutics nanocarriers. We successfully loaded the CNO-based nanocarrier with chemotherapeutic prodrugs derived from gemcitabine, and showed remarkable efficacy in killing CD44+ pancreatic adenocarcinoma cells, which are known to be gemcitabine résistant.

These findings demonstrate a robust pathway for advancing drug delivery techniques through the use of CNOs as nanocarriers, which signifies translational potentiel of carbon nanoparticles for targeted cancer therapy treatments.