Toxicological Aspects of Carbon Nanotubes, Fullerenes and Graphenes

Abstract

: Nanomedicines exhibit unbelievable capability in overcoming the hurdles faced in biological applications. Carbon nanotubes (CNTs), graphene-family nanomaterials and fullerenes are a class of engineered nanoparticles that have emerged as a new option for possible use in drug/gene delivery for life-threatening diseases. Their adaptability to pharmaceutical applications have opened new vistas for biomedical applications. Successful applications of this family of engineered nanoparticles in various fields may not support its use in medicine due to inconsistent data on toxicity as well as the lack of a centralized toxicity database. Inconsistent toxicological studies and lack of mechanistic understanding have been the reasons for less understanding of their toxicological aspects. These nanoparticles when underivatized or pristine are considered as safe however less reactive. The derivatized forms or functionalization changes their chemistry significantly to modify their biological effects including toxicity. They can cause acute and long term injuries in tissues by penetration through the blood-air barrier, blood-alveolus barrier, blood-brain barrier, and blood-placenta barrier etc. and by accumulating in the lung, liver, and spleen etc. The toxicological effects are manifested through inflammatory response, DNA damage, apoptosis, autophagy and necrosis. Other factors that largely influence the toxicity of carbon nanotubes, graphenes and fullerenes are the concentration, functionalization, dimensional and surface topographical factors. Thus better understanding of toxicity profile of CNTs, graphene-family nanomaterials and fullerenes in humans, animals and the environment is of significant importance, to improve their biological safety, to facilitate their wide biological application and for the successful commercial application. The exploration of appropriate cell lines to investigate specific receptors and intracellular targets as well as chronic toxicity beyond the proof-of-concept is required.

Recent advances in development of nanomedicines for multiple sclerosis diagnosis

“…However, since the application of nanomedicines to MS diagnosis is still in the infancy stage, more intensive preclinical and clinical trial studies are needed to improve the sensitivity and specificity of nanomedicine-based diagnosis methods so that these methods can be translated into clinical practice. Several studies have indicated that nanomedicines have intrinsic toxicity, including neurotoxicity, and cause adverse effects [169][170][171][172][173]. Their toxicity would greatly hamper their application in the diagnosis of MS.…”

Nanodiamond in cancer theranostics

“…Among them, carbon-based nanoparticles show great prospects as the next generation of effective multifunctional diagnostic and therapeutic agents because of their excellent physicochemical properties, thermal, low intrinsic toxicity, low cost of production on a large scale, versatile surface functionalization, and optical properties [21][22][23][24][25]. Such properties cast carbon-based nanomaterials as favorable candidates for nanomedicine, but different nanocarbon materials have the toxicity effects [26][27][28][29]. While nanodiamond (ND) is one of the least toxic of all carbon-based nanomaterials tested to date [30,31] and is a potential nanomedicine platform for circumventing drug efflux mechanisms in tumor cells and for enhancing intracellular drug retention [32,33].…”

Theoretical investigation of the mechanism of phospholipid extraction from the cell membrane using functionalized graphene quantum dots

“…Therefore, exploring the interaction between carbon nanomaterials and different organisms can better elucidate the potential toxicity of carbon nanomaterials. 16,17 As a new two-dimensional nanomaterial, graphene has attracted widespread attention since its discovery. 18 It has significant potential applications in medicine, especially in drug delivery, 19,20 disease diagnosis, 21 and medical imaging.…”

“…Therefore, exploring the interaction between carbon nanomaterials and different organisms can better elucidate the potential toxicity of carbon nanomaterials. 16,17…”