Self‐Assembled pH‐Sensitive Fluoromagnetic Nanotubes as Archetype System for Multimodal Imaging of Brain Cancer

Abstract

Fluoromagnetic systems are recognized as an emerging class of materials with great potential in the biomedical field. Here, it is shown how to fabricate fluoromagnetic nanotubes that can serve as multimodal probes for the imaging and targeting of brain cancer. An ionic self-assembly strategy is used to functionalize the surface of synthetic chrysotile nanotubes with pH-sensitive fluorescent chromophores and ferromagnetic nanoparticles. The acquired magnetic properties permit their use as contrast agent for magnetic resonance imaging, and enable the tracking of tumor cell migration and infiltration responsible for metastatic growth and disease recurrence. Their organic component, changing its fluorescence attitude as a function of local pH, targets the cancer distinctive acidity, and allows localizing and monitoring the tumor occurrence and progression by mapping the acidic spatial distribution within biopsy tissues. The fluoromagnetic properties of nanotubes are preserved from the in vitro to the in vivo condition and they show the ability to migrate across the blood brain barrier, thus spontaneously reaching the brain tumor after injection. The simplicity of the synthesis route of these geomimetic nanomaterials combined with their demonstrated affinity with the in vivo condition strongly highlights their potential for developing effective functional materials for multimodal theranostics of brain cancer.

A Porous Au@Rh Bimetallic Core–Shell Nanostructure as an H2O2‐Driven Oxygenerator to Alleviate Tumor Hypoxia for Simultaneous Bimodal Imaging and Enhanced Photodynamic Therapy

“…Here, pH 5 was used to mimic the real acidic tumor microenvironment. [ 44 ] As shown in Figure S14a (Supporting Information), comparable O 2 generation capacity was seen between pH 7.4 and 5.0, suggesting the applicability of Au@Rh‐CM to physiological pH. It is worth mentioning that the elevated temperature as a result of mild/moderate photothermal effect of Au@Rh‐CM (Figure 1h) might facilitate the catalytic decomposition of H 2 O 2 to O 2 .…”

Functionalized Scintillating Nanotubes for Simultaneous Radio- and Photodynamic Therapy of Cancer

“… 37 We employ synthetic chrysotile NTs as nanoscintillators because according to the literature, these nanostructures are highly biocompatible particles that can be prepared in aqueous solution under hydrothermal conditions in the presence of Mg and Si precursors. 38 With the chemical formula Mg 3 Si 2 O 5 (OH) 4 , chrysotile is a layered silicate having alternating layers of silica, SiO 2 , and brucite, Mg(OH) 2 ( Figure 1 d), 39 which are wrapped up giving rise to a tubular habit ( Figure 1 c). By tuning the reaction time, the size distribution of the NTs can be controlled to a certain extent.…”

A Review of the Current State of Nanomedicines for Targeting and Treatment of Cancers: Achievements and Future Challenges

“…Interestingly, one study demonstrated that fluoromagnetic nanotubes, administered by IV injection, crossed the blood brain barrier and located to the tumor site in Nod/Scid mice. [ 132 ]…”