**6. Carbon-based nanomaterials**

Carbon-based nanomaterials (CNBs) possess a singular structural dimension, which gives them special physicochemical properties interesting for several applications including as drug carriers [56]. CNBs can be classified as graphene, carbon nanotubes, mesoporous carbon, nanodiamonds, and fullerenes. All these structures differ in their excellent optical activities and multifunctional surface area, but all of them have demonstrated a high capacity for drug loading, biocompatibility, and low immunogenicity [57].

One of the principal areas of application of CNBs as drug carriers is in the treatment of several kinds of cancer, due to their excellent supramolecular π-π stacking, high absorption ability, and photothermal conversion capacity, among others [58]. Unfortunately, the use of CNBs in cancer therapy comes with undesirable secondary effects related to the cytotoxicity of healthy tissues [59].

Respecting their role as drug carriers, single-walled carbon nanotubes (SWCNTs) have been loaded with paclitaxel, doxorubicin, and isoniazid increasing the capacity of drug delivery, incrementing drug action, improved bioactivity in the destruction of bacterial cells [60–62]. Another example of CNBs such as fullerenes can be loaded with hydroxyurea, ibuprofen, chloroquine, doxorubicin, and N-desmethyl tamoxifen, giving them a better delivery efficiency of these pharmaceutical drugs [63–65].
