No abstract

No abstract

Carbon nanomaterials have attracted increasing attention in biomedicine recently to be used as drug nanocarriers suitable for medical treatments, due to their large surface area, high cellular internalization and preferential tumor accumulation, that enable these nanomaterials to transport chemotherapeutic agents preferentially to tumor sites, thereby reducing drug toxic side effects. However, there are widespread concerns on the inherent cytotoxicity of carbon nanomaterials, which remains controversial to this day, with studies demonstrating conflicting results. We investigated here in vitro toxicity of various carbon nanomaterials in human epithelial colorectal adenocarcinoma (Caco-2) cells and human breast adenocarcinoma (MCF-7) cells. Carbon nanohorns (CNH), carbon nanotubes (CNT), carbon nanoplatelets (CNP), graphene oxide (GO), reduced graphene oxide (GO) and nanodiamonds (ND) were systematically compared, using Pluronic F-127 dispersant. Cell viability after carbon nanomaterial treatment followed the order CNP < CNH < RGO < CNT < GO < ND, being the effect more pronounced on the more rapidly dividing Caco-2 cells. CNP produced remarkably high reactive oxygen species (ROS) levels. Furthermore, the potential of these materials as nanocarriers in the field of drug delivery of doxorubicin and camptothecin anticancer drugs was also compared. In all cases the carbon nanomaterial/drug complexes resulted in improved anticancer activity compared to that of the free drug, being the efficiency largely dependent of the carbon nanomaterial hydrophobicity and surface chemistry. These fundamental studies are of paramount importance as screening and risk-to-benefit assessment towards the development of smart carbon nanomaterial-based nanocarriers.

Alkanes in the presence of berberine sulfate provide an enhancement of fluorescent signal, which depends on alkane concentration and structure, when the system is irradiated with monochromatic UV light. Computational analysis suggests that an ion-induced dipole between alkanes and berberine sulfate is responsible for this phenomenon. This interaction can properly model the experimentally obtained fluorescent response. The proposed explanation allows other interacting systems to be designed, which have been experimentally confirmed.