Functionalized Carbon Nanostructures Versus Drug Resistance: Promising Scenarios in Cancer Treatment

Abstract

Carbon nanostructures (CN) are emerging valuable materials for the assembly of highly engineered multifunctional nanovehicles for cancer therapy, in particular for counteracting the insurgence of multi-drug resistance (MDR). In this regard, carbon nanotubes (CNT), graphene oxide (GO), and fullerenes (F) have been proposed as promising materials due to their superior physical, chemical, and biological features. The possibility to easily modify their surface, conferring tailored properties, allows different CN derivatives to be synthesized. Although many studies have explored this topic, a comprehensive review evaluating the beneficial use of functionalized CNT vs G or F is still missing. Within this paper, the most relevant examples of CN-based nanosystems proposed for MDR reversal are reviewed, taking into consideration the functionalization routes, as well as the biological mechanisms involved and the possible toxicity concerns. The main aim is to understand which functional CN represents the most promising strategy to be further investigated for overcoming MDR in cancer.

Keywords: cancer therapy; carbon nanohybrids; carbon nanostructures; multi-drug resistance.

Figure 1

General representation of the main MDR reversal mechanisms by nanoparticle systems (NP). Reproduced with permission from [4]. Copyright Elsevier (2017)

Figure 2

Schematic representation of the main carbon nanostructures covalent functionalization routes. CNT: carbon nanotubes; G: graphene; F: fullerenes. For each reaction, number codes and derivatizing agents are reported in Table 1.

Figure 3

General representation of the main mechanisms involved in the CNT cellular uptake. Reproduced with permission from [137] Elsevier (2016).

Figure 4

General representation of photothermal therapy by G derivatives. Adapted with permission from [198] copyright Elsevier (2018).