Delineating Toxicity Mechanisms Associated with MRI Contrast Enhancement through a Multidimensional Toxicogenomic Profiling of Gadolinium

Although gadolinium is widely used for magnetic resonance imaging in clinical settings, many concerns regarding its toxicity and bioaccumulation after gadolinium-based contrast agent (GBCA) administration have been raised and published...

In vitro and in vivo MRI imaging and photothermal therapeutic properties of Hematite (α-Fe2O3) Nanorods

Herein we report synthesis of hematite (α-Fe2O3) nanorods by calcinating hydrothermally synthesized goethite nanorods at 5000C. The structural, optical and MRI imaging guided cancer therapeutic properties of fabricated nanorods have been discussed in this manscript. FESEM and TEM imaging techniques were used to confirm the nanorod like morphology of as prepared materials. As we know that Fe2O3 nanorods with size in the range of 25–30 nm exhibit super magnetism. After coating with the PEG, the as prepared nanorods can be used as T2 MR imaging contrast agents. An excellent T2 MRI contrast of 38.763 mM–1s–1 achieved which is highest reported so far for α-Fe2O3. Besides the as prepared nanorods display an excellent photothermal conversion efficiency of 39.5% thus acts as an excellent photothermal therapeutic agent. Thus, we envision the idea of testing our nanorods for photothermal therapy and MR imaging application both in vitro and in vivo, achieving an excellent T2 MRI contrast and photothermal therapy effect with as prepared PEGylated nanorods.

All-In-One Approaches for Triple-Negative Breast Cancer Therapy: Metal-Phenolic Nanoplatform for MR Imaging-Guided Combinational Therapy

Background Conventional chemotherapy has poor efficacy in triple-negative breast cancer (TNBC) which is highly heterogeneous and aggressive. Imaging-guided therapy is usually combined with diverse treatment modalities, could realize the integration of diagnosis and treatments. Therefore, the primary challenge for combinational therapy is designing proper delivery systems to accomplish multiple synergistic effects. Results Herein, a facile nanoplatform is manufactured to fulfill the all-in-one approaches for TNBC combinational therapy. Fe3+-based metal-phenolic networks (MPNs) with bovine serum albumin (BSA) modification serve as drug delivery carriers to encapsulate bleomycin (BLM), forming BFE NPs@BSA. It is found that BFE NPs@BSA could be further used as photothermal transduction agents and T1-weighted magnetic resonance imaging (MRI) contrast agents. Once internalized into tumor cells, released BLM could cause DNA damage, while Fenton reactions are initiated to produce highly toxic •OH. Upon laser irradiation, BFE NPs@BSA could convert light into heat to achieve synergistic therapeutic effects. Moreover, as T1-weighted MRI contrast agents, BFE NPs@BSA could provide diagnosis and treatment monitoring for individualized precise therapy. Conclusions This strategy provides an all-in-one theranostic nanoplatform for MRI-guided combinational therapy against TNBC.

Differential Spatial Distribution of TSPO or Amino Acid PET Signal and MRI Contrast Enhancement in Gliomas

In this study, dual PET and contrast enhanced MRI were combined to investigate their correlation per voxel in patients at initial diagnosis with suspected glioblastoma. Correlation with contrast enhancement (CE) as an indicator of BBB leakage was further used to evaluate whether PET signal is likely caused by BBB disruption alone, or rather attributable to specific binding after BBB passage. PET images with [18F]GE180 and the amino acid [18F]FET were acquired and normalized to healthy background (tumor-to-background ratio, TBR). Contrast enhanced images were normalized voxel by voxel with the pre-contrast T1-weighted MRI to generate relative CE values (rCE). Voxel-wise analysis revealed a high PET signal even within the sub-volumes without detectable CE. No to moderate correlation of rCE with TBR voxel-values and a small overlap as well as a larger distance of the hotspots delineated in rCE and TBR-PET images were detected. In contrast, voxel-wise correlation between both PET modalities was strong for most patients and hotspots showed a moderate overlap and distance. The high PET signal in tumor sub-volumes without CE observed in voxel-wise analysis as well as the discordant hotspots emphasize the specificity of the PET signals and the relevance of combined differential information from dual PET and MRI images.