A Review of Theranostics Applications and Toxicities of Carbon Nanomaterials

BACKGROUND

In the last few years, the use of modified Carbon Nanomaterials (CNMs) for theranostics (therapeutic and diagnosis) applications is a new and rapidly growing area in pharmacy and medical fields. Owing to this, their specific physicochemical behaviors like high stability, drug loading, surface area to volume ratio, with low toxicity and immunogenicity are mainly responsible to be considered those as smart nanomaterials.

OBJECTIVES

This review describes the different dimensions of carbon-based nanocarriers including 0-D fullerene, 1-D Carbon Nanotubes (CNTs), and 2-D graphene and Graphene Oxide (GO) and their surface modification with different biocompatible and biodegradable molecules via covalent or non-covalent functionalization. The major focus of this article is on the different theranostics applications of CNMs like targeted drugs and genes delivery, photodynamic therapy, photothermal therapy, bioimaging, and biosensing. The therapeutic efficacy of drugs could be enhanced by delivering them directly on a specific site using different targeted ligands such as vitamins, peptide, carbohydrates, proteins, etc. A section of the article also discusses the toxicity of the CNMs to the living systems.

CONCLUSIONS

In brief, this review article discusses the numerous theranostics applications and toxicities of CNMs.

Toxicity of dextran stabilized fullerene C60 against C6 Glial cells

Elevated application potential of fullerene C₆₀ paved the way to think on its adverse effect when it reaches to biological system and environment. Though fullerenes are insoluble in water, various strategies are employed to make it soluble. Method of solubilization with organic solvents, yield cytotoxic responses both in vitro and in vivo. In this study, dextran was used to stabilize C₆₀ particle. Fourier transformed-infrared spectroscopy (FT-IR) and transition electron microscopy (TEM) were used for characterization and it confirms effective surface stabilization and morphological characteristics. This was followed by various cytotoxicity studies to evaluate its bio-nano interactions. The results of the study suggest that the dextran stabilized C₆₀ nanoparticles (Dex-C₆₀) forms uniform suspension in water and was stable up to 72 h. The C6 glial cell-Dex-C₆₀ interactions indicated that the Dex-C₆₀ nanoparticles penetrate deeper into the cells and cause dose dependent toxic response. The result of the study recommended that Dex-C₆₀ nanoparticles should undergo intensive risk assessment before biomedical applications and should take proper safety measure to avoid its entry to the environment.

Cytoskeletal synchronization of CHO cells with polymer functionalized fullerene C60

Recent developments in the field of fullerene C₆₀ and its derivatives suggest its suitability in a wide range of applications ranging from photovoltaic instruments, development of solar based cells, cosmetics to enzyme inhibition treatment, and so on. These innovative applications raised possibilities of intentional or oblivious human-particle contact leading to possible deleterious effects on human health. The current study deals with the interaction of dextran functionalized fullerene C₆₀ (Dex-C₆₀) on Chinese Hamster Ovary cells. The results showed that the cell viability was not affected by Dex-C₆₀ treatment even at higher concentrations. Treatment of Dex-C₆₀ did not affect mitochondrial membrane potential and the integrity of lysosomal and cytoskeletal membrane. DNA ladder assay and nuclear staining showed that the DNA remains intact, and no fragmentation or nuclear condensation was visible. From flow cytometry analysis, the viable population of treated cells was seemed to be remaining similar to that of untreated cells. Hence, from the current result, it is concluded that Dex-C₆₀ can be a potential candidate for various biomedical applications.