A concise review of carbon nanotube's toxicology

Carbon nanotubes can be either single-walled or multi-walled, each of which is known to have a different electron arrangement and as a result have different properties. However, the shared unique properties of both types of carbon nanotubes (CNT) allow for their potential use in various biomedical devices and therapies. Some of the most common properties of these materials include the ability to absorb near-infra-red light and generate heat, the ability to deliver drugs in a cellular environment, their light weight, and chemical stability. These properties have encouraged scientists to further investigate CNTs as a tool for thermal treatment of cancer and drug delivery agents. Various promising data have so far been obtained about the usage of CNTs for cancer treatment; however, toxicity of pure CNTs represents a major challenge for clinical application. Various techniques both in vivo and in in vitro have been conducted by a number of different research groups to establish the factors which have a direct effect on CNT-mediated cytotoxicity. The main analysis techniques include using Alamar blue, MTT, and Trypan blue assays. Successful interpretation of these results is difficult because the CNTs can significantly disrupt the emission of the certain particles, which these assays detect. In contrast, in vivo studies allow for the measurement of toxicity and pathology caused by CNTs on an organismal level. Despite the drawbacks of in vitro studies, they have been invaluable in identifying important toxicity factors, such as size, shape, purity, and functionalisation, the latter of which can attenuate CNT toxicity

Biological dosimetry for breast cancer radiotherapy: a comparison of external beam and intraoperative radiotherapy

Purpose: External beam radiotherapy (EBRT) is the gold standard adjuvant treatment after breast conserving surgery although a recent phase 3 trial has shown the non-inferiority of intraoperative radiotherapy (IORT). Radiation exposure of the heart and cardiac vessels causes an increase in morbidity and mortality following EBRT for breast cancer. We have used γ-H2AX foci formation in peripheral blood lymphocytes as a surrogate marker of dose delivered to the heart and great vessels and have assessed the feasibility of using this technique for biological dosimetry. Methods: 34 patients were recruited, having either EBRT or IORT as part of a randomised controlled trial (TARGIT). Blood samples were taken prior to and after first fraction of radiotherapy, and the γ-H2AX biomarker then quantified. Results: Data were available for 31 patients. Following TARGIT-IORT there was an increase of 0.203 foci per cell (range -1.436 to 1.275) compared with 0.935 foci per cell (range -0.679 to 2.216) in the EBRT group; this difference was highly significant (p = 0.009). As TARGIT-IORT treatment is completed with a single fraction, whilst EBRT requires at least 15 fractions, the actual difference is estimated to be many times more. Conclusions: These data show a significantly greater change in γ-H2AX foci number per cell following one fraction of EBRT compared to TARGIT-IORT. This is the first study to demonstrate this effect using a biomarker and demonstrates a proof of concept methodology for similar applications

Application of OctaAmmonium-POSS functionalized single walled carbon nanotubes for thermal treatment of cancer

Introduction: Single walled carbon nanotubes (SWCNTs) have distinctive physical and chemical properties. Additionally, innovative properties can be established to match the clinical need by attachment of functional groups to the SWCNT. In this experiment SWCNT was functionalized with OctaAmmonium-POSS. Evidence suggests that functionalization of SWCNT with OctaAmmonium-POSS would augment the dispersion of SWCNT. We further postulate that functionalization of SWCNT with OctaAmmonium-POSS would enhance the temperature increase of SWCNT upon exposure to NIR laser irradiation. Methods: Functionalization of SWCNT was conferred by refluxing with acid and OctaAmmonium-POSS. Fourier Transform Infrared (FTIR) test UV-visible spectroscopy and morphology analysis using Transmission Electron Microscopy (TEM) confirmed successful functionalization of SWCNT. NIR irradiation of samples was conducted using an 808 nm laser at 1 watt. Temperature changes were documented using a thermal camera. A HT-29 colorectal cancer cell line was used as a model for photothermal ablation. Cell viability test was performed using trypan blue and fluorescence activated cell sorting (FACS) technique. Graph plotting and statistical analysis was conducted using Graph Pad Prism. Results: Following the functionalization process, TEM images showed a layer on the surface of the SWCNT. In the FTIR experiment, results illustrated the presence of the -COOH group on the functionalized SWCNTs. Upon further functionalization of SWCNT with OctaAmmonium-POSS, various peaks determined the formation of amide bond between the POSS molecule and functionalized SWCNT. The UV-visible spectra also determine the successful functionalization of the SWCNT following its treatment with acid and OctaAmmonium-POSS. Upon exposure to NIR, OctaAmmonium-POSS-SWCNT was the only treatment group that illustrated significantly higher temperature increase than the other treatment groups. Additionally cell death of NIR irradiated OctaAmmonium-POSS-SWCNT was statistically significant compared to other treatment groups. Conclusion: OctaAmmonium-POSS was used to render SWCNT biocompatible and water dispersible. Observation from this study determines that functionalization with OctaAmmonium-POSS show greater temperature increase compared to pristine SWCNTs upon its exposure NIR. This significant temperature increase is due to increasing the solubility of SWCNT following its functionalization with OctaAmmonium-POSS

Carbon nanotubes in the diagnosis and treatment of malignant melanoma

The potential role of carbon nanotubes (CNTs) in the diagnosis and treatment of malignant melanoma (MM) is still an emerging area of research. To date, there is strong evidence for the efficiency of CNTs in this therapeutic area, despite their unique physical, mechanical and biological properties. In this review, the application of CNTs in cancer diagnostics and treatment is reviewed, and consideration is given to the toxicity issues associated with their use

A new era of cancer treatment: carbon nanotubes as drug delivery tools

Cancer is a generic term that encompasses a group of diseases characterized by an uncontrolled proliferation of cells. There are over 200 different types of cancer, each of which gains its nomenclature according to the type of tissue the cell originates in. Many patients who succumb to cancer do not die as a result of the primary tumor, but because of the systemic effects of metastases on other regions away from the original site. One of the aims of cancer therapy is to prevent the metastatic process as early as possible. There are currently many therapies in clinical use, and recent advances in biotechnology lend credence to the potential of nanotechnology in the fight against cancer. Nanomaterials such as carbon nanotubes (CNTs), quantum dots, and dendrimers have unique properties that can be exploited for diagnostic purposes, thermal ablation, and drug delivery in cancer. CNTs are tubular materials with nanometer-sized diameters and axial symmetry, giving them unique properties that can be exploited in the diagnosis and treatment of cancer. In addition, CNTs have the potential to deliver drugs directly to targeted cells and tissues. Alongside the rapid advances in the development of nanotechnology-based materials, elucidating the toxicity of nanoparticles is also imperative. Hence, in this review, we seek to explore the biomedical applications of CNTs, with particular emphasis on their use as therapeutic platforms in oncology

Stem cell tracking using iron oxide nanoparticles

Superparamagnetic iron oxide nanoparticles (SPIONs) are an exciting advancement in the field of nanotechnology. They expand the possibilities of noninvasive analysis and have many useful properties, making them potential candidates for numerous novel applications. Notably, they have been shown that they can be tracked by magnetic resonance imaging (MRI) and are capable of conjugation with various cell types, including stem cells. In-depth research has been undertaken to establish these benefits, so that a deeper level of understanding of stem cell migratory pathways and differentiation, tumor migration, and improved drug delivery can be achieved. Stem cells have the ability to treat and cure many debilitating diseases with limited side effects, but a main problem that arises is in the noninvasive tracking and analysis of these stem cells. Recently, researchers have acknowledged the use of SPIONs for this purpose and have set out to establish suitable protocols for coating and attachment, so as to bring MRI tracking of SPION-labeled stem cells into common practice. This review paper explains the manner in which SPIONs are produced, conjugated, and tracked using MRI, as well as a discussion on their limitations. A concise summary of recently researched magnetic particle coatings is provided, and the effects of SPIONs on stem cells are evaluated, while animal and human studies investigating the role of SPIONs in stem cell tracking will be explored