Magnetic carbon nanotubes with particle-free surfaces and high drug loading capacity

Abstract

Open-ended, multi-wall carbon nanotubes (CNTs) with magnetic nanoparticles encapsulated within their graphitic walls (magCNTs) were fabricated by a combined action of templated growth and a ferrofluid catalyst/carbon precursor, and tested as drug hosts. The hybrid nanotubes are stable under extreme pH conditions due to particle protection provided by the graphitic shell. The magCNTs are promising for high capacity drug loading given that the magnetic functionalization did not block any of the active sites available for drug attachment, either from the CNT internal void or on the internal and external surfaces. This is in contrast to typical approaches of loading CNTs with particles that proceed through surface attachment or capillary filling of the tube interior. Additionally, the CNTs exhibit enhanced hydrophilic character, as shown by water adsorption measurements, which make them suitable for biological applications. The morphological and structural characteristics of the hybrid CNTs are evaluated in conjunction to their magnetic properties and ability for drug loading (diaminophenothiazine). The fact that the magnetic functionality is provided from 'inside the walls' can allow for multimode functionalization of the graphitic surfaces and makes the magCNTs promising for targeted therapeutic applications.

Multifunctional Ferromagnetic Carbon‐Nanotube Arrays Prepared by Pulse‐Injection Chemical Vapor Deposition

“…The catalyst particle (Fe 3 C) moves up with the cap of the MWCNT (Figure 1 h). [12][13][14][15][16][17][18] The corresponding relationship between diameters of the metal NPs and H c (Figure 2 c, inset) confirms the exceptional magnetic characteristics of Fe 3 C@MWCNT synthesized by the pulse-injection CVD. Once the flow of toluene/ferrocene solution is restarted, a new catalyst particle forms on the terminated MWCNTs and a second layer of MWCNT begins to grow on the previous MWCNT (Figure 1 i).…”

Modification of Carbon Nanotubes as an Effective Solution for Cancer Therapy

“…However, the attachment of iron oxide nanoparticles and QDs on the active surface of CNTs considerably plummeted the CNTs capacity for drug storage and further functionalization [170,171]. Additionally, direct contact of Quantum dots with iron oxide nanoparticles on CNTs surface causes fluorescence quenching and diminishes the magneticfluorescent dual functionality.…”

Flexible Ferrofluids: Design and Applications

“…In recent decades, ferromagnetic particles have been demonstrated to open a new vista in efficient, low‐side‐effect disease treatment . After modified with substances (e.g., polymers and silica nanoparticles) and forming special structures (e.g., core–shell), the ferromagnetic particles could carry antibodies or drugs and deliver them to lesion areas . In addition, ascribed to magnetic hyperthermia, ferromagnetic particles could kill tumor cells when they are heated under an external magnetic field .…”