Photothermal cancer therapy using graphitic carbon–coated magnetic particles prepared by one-pot synthesis

Abstract

We describe here a simple synthetic strategy for the fabrication of carbon-coated Fe 3 O 4 (Fe 3 O 4 @C) particles using a single-component precursor, iron (III) diethylenetriaminepentaacetic acid complex. Physicochemical analyses revealed that the core of the synthesized particles consists of ferromagnetic Fe 3 O 4 material ranging several hundred nanometers, embedded in nitrogen-doped graphitic carbon with a thickness of ~120 nm. Because of their photothermal activity (absorption of near-infrared [NIR] light), the Fe 3 O 4 @C particles have been investigated for photothermal therapeutic applications. An example of one such application would be the use of Fe 3 O 4 @C particles in human adenocarcinoma A549 cells by means of NIR-triggered cell death. In this system, the Fe 3 O 4 @C can rapidly generate heat, causing >98% cell death within 10 minutes under 808 nm NIR laser irradiation (2.3 W cm −2 ). These Fe 3 O 4 @C particles provided a superior photothermal therapeutic effect by intratumoral delivery and NIR irradiation of tumor xenografts. These results demonstrate that one-pot synthesis of carbon-coated magnetic particles could provide promising materials for future clinical applications and encourage further investigation of this simple method.

Iron Ores and Iron Oxide Materials

“…The use of inorganic compounds such as gold, silver, silica gel and carbon as surfactants not only provides good stability to the nanoparticles but also allows functionalizing their surface by grafting certain biological ligands. Covering of magnetic nanoparticles with gold seems to be ideal because of its low reactivity; however, coating the magnetic nanoparticles directly with gold is very difficult due to the different nature of the two surfaces [86][87][88][89]. The silica gel is the most widely used compound in the preparation of functionalized iron oxide nanoparticles surface, because it has several advantages: excellent biocompatibility, hydrophilicity, the feasibility of integrating other functional groups on the surface due to terminal silanol groups that can react with different coupling agents, provides good stabilization of the magnetic iron oxide nanoparticles in the solution, prevents the interaction between the nanoparticles thus preventing the agglomeration of the particles over time and ensures better encapsulation [90].…”

Fabrication of Silica-Coated Hollow Carbon Nanospheres Encapsulating Fe3O4 Cluster for Magnetical and MR Imaging Guided NIR Light Triggering Hyperthermia and Ultrasound Imaging

“…Until recently, the aggregated core−shell Fe 3 O 4 @C nanospheres with size of ∼850 nm was intratumoral injection of adenocarcinoma A549 tumors to conduct photothermal ablation. 8 Herein, we synthesized a silica-coated hollow carbon nanospheres encapsulating IONPs cluster (a yolk−shell structure denoted as SiO 2 /h-Fe 3 O 4 @C) to conduct magnetically and MR imaging guided NIR light activating photothermal hyperthermia and ultrasound (US) imaging in the systemic study. Not limited to the well-known functionalities in magnetic targeting and MR imaging, we expanded this yolk− shell structure as a NIR-responsive echogenic nanoagent giving an enhanced ultrasound imaging.…”

“…The emerging one-dimensional nanotubes and two-dimensional graphene oxides have shed light on the applications in all aspects of fields including nanomedicine. These graphitic nanomaterials have given the capability for photoactivated therapy against malignant tumors as one of the important therapeutic treatments in biomedical applications because of their absorption in near-infrared (NIR) area. − Adjunct magnetic iron oxide nanoparticles (IONPs), Fe 3 O 4 , provide adjuvant functionalities to implement magnetical targeting as well as the magnetic resonance (MR) imaging guided therapy. IONP-carbon (C) hybrid zero dimensional nanostructures are normally aware of core–shell and yolk–shell architectures.…”

“…IONP-carbon (C) hybrid zero dimensional nanostructures are normally aware of core–shell and yolk–shell architectures. Among those structures, little effort has been put into the fabrication of yolk–shell relative to the core–shell structures. − Although IONP-C is a prevalent hybrid nanostructure and can be developed to a promising theranostic nanoagent, the in vivo study has surprisingly been sketchily described. Until recently, the aggregated core–shell Fe 3 O 4 @C nanospheres with size of ∼850 nm was intratumoral injection of adenocarcinoma A549 tumors to conduct photothermal ablation …”

“…The dispersed yolk–shell nanospheres in aqueous solution were eligible for biomedical studies in vivo. Among the reported approaches, the occurrence of the aggregation has been commonly observed for the annealed C nanospheres and has highly depended on experimental conditions. ,,− ,,− It might be the reason that the resulting aggregation might have delayed the development of the IONP-C hybrid nanostructures applied for in vivo studies.…”