Carbon-covered magnetic nanomaterials and their application for the thermolysis of cancer cells

3D-printed magnetic Fe3O4/MBG/PCL composite scaffolds with multifunctionality of bone regeneration, local anticancer drug delivery and hyperthermia

In this study, three-dimensional (3D) magnetic Fe₃O₄ nanoparticles containing mesoporous bioactive glass/polycaprolactone (Fe₃O₄/MBG/PCL) composite scaffolds have been fabricated by the 3D-printing technique. The physiochemical properties, in vitro bioactivity, anticancer drug delivery, mechanical strength, magnetic heating ability and cell response of Fe₃O₄/MBG/PCL scaffolds were systematically investigated. The results showed that Fe₃O₄/MBG/PCL scaffolds had uniform macropores of 400 μm, high porosity of 60% and excellent compressive strength of 13-16 MPa. The incorporation of magnetic Fe₃O₄ nanoparticles into MBG/PCL scaffolds did not influence their apatite mineralization ability but endowed excellent magnetic heating ability and significantly stimulated proliferation, alkaline phosphatase (ALP) activity, osteogenesis-related gene expression (RUNX2, OCN, BSP, BMP-2 and Col-1) and extra-cellular matrix (ECM) mineralization of human bone marrow-derived mesenchymal stem cells (h-BMSCs). Moreover, using doxorubicin (DOX) as a model anticancer drug, Fe₃O₄/MBG/PCL scaffolds exhibited a sustained drug release for use in local drug delivery therapy. Therefore, the 3D-printed Fe₃O₄/MBG/PCL scaffolds showed the potential multifunctionality of enhanced osteogenic activity, local anticancer drug delivery and magnetic hyperthermia.

Toxicity and efficacy of carbon nanotubes and graphene: the utility of carbon-based nanoparticles in nanomedicine

Carbon-based nanomaterials have attracted great interest in biomedical applications such as advanced imaging, tissue regeneration, and drug or gene delivery. The toxicity of the carbon nanotubes and graphene remains a debated issue although many toxicological studies have been reported in the scientific community. In this review, we summarize the biological effects of carbon nanotubes and graphene in terms of in vitro and in vivo toxicity, genotoxicity and toxicokinetics. The dose, shape, surface chemistry, exposure route and purity play important roles in the metabolism of carbon-based nanomaterials resulting in differential toxicity. Careful examination of the physico-chemical properties of carbon-based nanomaterials is considered a basic approach to correlate the toxicological response with the unique properties of the carbon nanomaterials. The reactive oxygen species-mediated toxic mechanism of carbon nanotubes has been extensively discussed and strategies, such as surface modification, have been proposed to reduce the toxicity of these materials. Carbon-based nanomaterials used in photothermal therapy, drug delivery and tissue regeneration are also discussed in this review. The toxicokinetics, toxicity and efficacy of carbon-based nanotubes and graphene still need to be investigated further to pave a way for biomedical applications and a better understanding of their potential applications to humans.

Aqueous stabilisation of carbon-encapsulated superparamagnetic α-iron nanoparticles for biomedical applications

Carbon-encapsulated superparamagnetic α-Fe nanoparticles were stabilised in aqueous media allowing their cell internalisation.

Tumor photothermolysis: using carbon nanomaterials for cancer therapy

Carbon nanomaterials have unique physicochemical properties based solely on their small size, which makes them ideal for nano-oncology. While there have been tremendous advances in the current treatment of high-risk cancers, conventional treatment still causes harm to the surrounding healthy tissue. Carbon nanomaterials such as carbon nanotubes, carbon nanohorns, and graphenes have been increasingly used in the field of cancer photothermal therapy. Through surface functionalization, carbon nanomaterials can be specifically targeted to the tumorous tissue allowing for an increase in therapeutic potential. The unique photo-electron transfer features of carbon nanomaterials coupled with functional moieties, is proving useful for their use in the photothermolysis of cancer cells.

Toward improved selectivity of targeted delivery: the potential of magnetic nanoparticles

Magnetic nanoparticles, mostly iron oxide-based nanoparticles, have long been used as contrasting agents in magnetic resonance imaging (MRI) applications, heat mediators in hyperthermia treatments and carriers for targeted drug delivery. Magnetic nanoparticles offer some attractive characteristics for targeted drug delivery such as drug carrying ability, nano-scale dimensions and magnetism-driven selective targeting. In this issue, Escribano et al. demonstrated that iron oxide-based magnetic nanoparticles with an implanted magnet can improve selective targeting to the site of inflammation. This result opens a promising avenue for magnetic drug targeting to inflammatory diseases.

Multifunctional magnetic nanoparticles for synergistic enhancement of cancer treatment by combinatorial radio frequency thermolysis and drug delivery

Few-layer, carbon-coated, iron (C/Fe) magnetic nanoparticles (MNPs) were synthesized with controlled sizes ranging from 7 to 9 nm. The additional loading of two anti-cancer drugs, doxorubicin and erlotinib, was achieved through - stacking onto the carbon shells. Controlled release of the drugs was successfully triggered by radio frequency (RF) heating or pH variation. Based on the experimental results, C/Fe MNPs act as heat-inducing agents and are able to thermally destroy cancer cells when RF is applied. It was found that the combination of anti-cancer drugs (in particular a low dose of doxorubicin) and RF treatment demonstrates a synergistic effect in inducing cell death in pancreatic cancer cells. Our findings demonstrate that MNPs can be used as highly efficient multimodal nanocarrier agents for an integrated approach to cancer treatment involving triggered delivery of antineoplastic drugs and RF-induced thermal therapy.

Effective colon cancer prophylaxis in mice using embryonic stem cells and carbon nanotubes

Introduction

In recent years, a new concept of an anticancer vaccine has been proposed to prevent and control the proliferation and expansion of cancer cells by eliciting an immune boost in biological systems. The recent literature supports the role of embryonic stem cells (ESC) as cellular agents that stimulate the biological systems to destroy cancer cells. However, at present, a true anticancer vaccine remains elusive. There are several lines of evidence showing that carbon nanotubes may be used to initiate and maintain immune responses.

Objective

The authors proposed to test the therapeutic potential of multiwalled carbon nanotubes (MWCNTs) combined with ESC as agents to induce an immune boost and provide subsequent anticancer protection in mice.

Methods

C57 BL/6 mice were immunized with ESC and MWCNTs.

Results

The proposed vaccine led to significant antitumor responses and enhanced tumor rejection in mice with subcutaneous inoculation of MC38 colon malign cells compared with groups only administered ESC, only MWCNTs, and controls.

Conclusion

The application and potential of ESC combined with MWCNTs as anticancer immunization agents may represent the beginning of a new chapter in the treatment of colon cancer.

Engineered nanostructural materials for application in cancer biology and medicine

Nanotechnology covers a wide variety of fields of research, including chemistry, physics, biology and medicine, with extensive applications in cancer, ranging from accurate, early detection of malignant lesions to minimizing metastasis. Continued development of cancer-targeted therapy has promising advantages: maximizing the effectiveness of anticancer drugs while decreasing the harmful systemic effects; tumor destruction via heating that takes advantage of magnetic nanoparticles' size, magnetization and biocompatibility; novel drug-delivery systems; and gene therapy functions to facilitate controlled drug loading and release inside the cytoplasm. These and other nanotechnology applications can contribute essential new knowledge in the fight against cancer.

Advances in cancer therapy through the use of carbon nanotube-mediated targeted hyperthermia

Carbon nanotubes (CNTs) are emerging versatile tools in nanomedicine applications, particularly in the field of cancer targeting. Due to diverse surface chemistry and unique thermal properties, CNTs can act as strong optical absorbers in near infrared light where biological systems prove to be highly transparent. The process of laser-mediated ablation of cancer cells marked with biofunctionalized CNTs is frequently termed "nanophotothermolysis." This paper illustrates the potential of engineered CNTs as laser-activated photothermal agents for the selective nanophotothermolysis of cancer cells.

Review on the progress in synthesis and application of magnetic carbon nanocomposites

This review focuses on the synthesis and application of nanostructured composites containing magnetic nanostructures and carbon-based materials. Great progress in fabrication of magnetic carbon nanocomposites has been made by developing methods including filling process, template-based synthesis, chemical vapor deposition, hydrothermal/solvothermal method, pyrolysis procedure, sol-gel process, detonation induced reaction, self-assembly method, etc. The applications of magnetic carbon nanocomposites expanded to a wide range of fields such as environmental treatment, microwave absorption, magnetic recording media, electrochemical sensor, catalysis, separation/recognization of biomolecules and drug delivery are discussed. Finally, some future trends and perspectives in this research area are outlined.

Nanoparticles: heating tumors to death?

Thermotherapy consisting of heating tumors to death appears to be a suitable method to achieve tumor ablation in a noninvasive manner with minimal side effects but developments were hampered because of the lack of specificity of the heating method. New interests have emerged by introducing nanoparticles as energy absorbent agents in tumor tissue to locally enhance the action of irradiation, hence increasing the specificity of the method. Mechanisms of tumor death depend on the nature of the nanoparticles and irradiation modalities. They can be induced either by heat-dependent or by heat-independent phenomena. As discussed in this article, it can reasonably be expected that the recent methods of thermotherapy developed with nanoparticles have a tremendous potential for cancer treatments. However, overcoming challenging milestones is now required before the method will be ready for the treatment of a wide range of cancers.

Influence of Gold Nanoshell on Hyperthermia of Super Paramagnetic Iron Oxide Nanoparticles (SPIONs)

Gold nanoshell around super paramagnetic iron oxide nanoparticles (SPIONs) was synthesized and small angle X-ray scattering (SAXS) analysis suggests a gold coating of approximately 0.4 to 0.5 nm thickness. On application of low frequency oscillating magnetic fields (44 - 430 Hz), a four- to five-fold increase in the amount of heat released with gold-coated SPIONs (6.3 nm size) in comparison with SPIONs (5.4 nm size) was observed. Details of the influence of frequencies of oscillating magnetic field, concentration and solvent on heat generation are presented. We also show that, in the absence of oscillating magnetic field, both SPIONs and SPIONs@Au are not particularly cytotoxic to mammalian cells (MCF-7 breast carcinoma cells and H9c2 cardiomyoblasts) in culture, as indicated by the reduction of 3-(4,5-dimethylthiazol-2-yl)-5-(3-carboxymethoxyphenyl)-2-(4-sulfophenyl)-2H-tetrazolium by viable cells in a phenazine methosulfate-assisted reaction.