Functionalization of single-walled carbon nanohorns for simultaneous fluorescence imaging and cisplatin delivery in vitro

Single-walled carbon nanohorns (SWNHs) have been shown to be effective photothermal enhancers and drug delivery agents for potential cancer therapy, particularly for the eradication of bladder cancer lesions. In this study, the potential for SWNHs to serve as nanotheranostic vehicles is demonstrated through simultaneous delivery of the chemotherapeutic cisplatin from SWNH cone interiors and imaging of the nanoparticle transport to tumor cells using conjugated quantum dots (QDs). Following the formation of cisplatin-modified SWNH-QD (SWNH-QD + cis) hybrids, their characterization by scanning and transmission electron microscopy (STEM, TEM), energy dispersive spectroscopy (EDS), and dynamic light scattering (DLS) were performed to characterize the composite nanoparticles. Drug release profiles and 50% inhibitory concentration (IC50) determination showed that QDs do not hinder the therapeutic ability of SWNHs. In addition, the hybrids were trackable over the course of a 3 day period, which indicates that internalized SWNHs can continue to deliver therapy after removal of the nano-agents from the cell culture. This unique SWNH hybrid can successfully be used as an imaging agent to study nanoparticle transport and consequently the delivery of a therapeutic to the targeted cancer cells.