Increased transverse relaxivity in ultrasmall superparamagnetic iron oxide nanoparticles used as MRI contrast agent for biomedical imaging

Mishra, Sushanta Kumar; Kumar, B.S. Hemanth; Khushu, Subash; Tripathi, Renu; Gangenahalli, Gurudutta

doi:10.1002/cmmi.1698

Cited by 40 publications

(22 citation statements)

References 48 publications

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“…T 2 ‐weighted MR relaxometry measurements of sample phantoms at the same Fe mass concentrations were examined at a magnetic field of 7.0 T. The T 2 ‐weighted MR signal becomes darker with an increasing concentration of the CP‐IO nanocomposites ( Figure A). An average r 2 value of 98 mM −1 s −1 of CP‐IO nanocomposites was calculated, which is comparable with the literature values of water‐dispersible IO nanoparticles of similar sizes (Figure B) …”

Section: Resultssupporting

confidence: 88%

Photoacoustic and Magnetic Resonance Imaging Bimodal Contrast Agent Displaying Amplified Photoacoustic Signal

Duan

Mao

et al. 2018

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Progress in photoacoustic (PA) and magnetic resonance imaging (MRI) bimodal contrast agents has been achieved mainly by utilizing the imaging capability of single or multiple components and consequently realizing the desired application for both imaging modalities. However, the mechanism of the mutual influence between components within a single nanoformulation, which is the key to developing high‐performance multimodal contrast agents, has yet to be fully understood. Herein, by integrating conjugated polymers (CPs) with iron oxide (IO) nanoparticles using an amphiphilic polymer, a bimodal contrast agent named CP‐IO is developed, displaying 45% amplified PA signal intensity as compared to bare CP nanoparticle, while the performance of MRI is not affected. Further experimental and theoretical simulation results reveal that the addition of IO nanoparticles in CP‐IO nanocomposites contributes to this PA signal amplification through a synergistic effect of additional heat generation and faster heat dissipation. Besides, the feasibility of CP‐IO nanocomposites acting as PA‐MRI bimodal contrast agents is validated through in vivo tumor imaging using mice models. From this study, it is demonstrated that a delicately designed structural arrangement of various components in a contrast agent could potentially lead to a superior performance in the imaging capability.

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Section: Resultssupporting

confidence: 88%

Photoacoustic and Magnetic Resonance Imaging Bimodal Contrast Agent Displaying Amplified Photoacoustic Signal

Duan

Mao

et al. 2018

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“…However, after being exposed to an external magnetic field, RB-MMSNs were quickly assembled to the side near the magnet ( Figure 4B, inset). Superparamagnetic Fe 3 O 4 nanoparticles are a good T 2 contrast agent, [34][35][36] depending on the darkening effect to distinguish the contrast area with normal sites. T 2 -weighted MRI showed a concentration-dependent darkening effect, and the relaxation rate (R 2 ) of RB-MMSNs was ~52.51 S Determination of RB loading efficiency, ph-responsive release in vitro and detection of singlet oxygen…”

Section: Resultsmentioning

confidence: 99%

Magnetic and pH dual-responsive mesoporous silica nanocomposites for effective and low-toxic photodynamic therapy

Zhan¹,

Ma²,

Wang³

et al. 2017

IJN

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Nonspecific targeting, large doses and phototoxicity severely hamper the clinical effect of photodynamic therapy (PDT). In this work, superparamagnetic Fe 3 O 4 mesoporous silica nanoparticles grafted by pH-responsive block polymer polyethylene glycol- b -poly(aspartic acid) (PEG- b -PAsp) were fabricated to load the model photosensitizer rose bengal (RB) in the aim of enhancing the efficiency of PDT. Compared to free RB, the nanocomposites (polyethylene glycol- b -polyaspartate-modified rose bengal-loaded magnetic mesoporous silica [RB−MMSNs]) could greatly enhance the cellular uptake due to their effective endocytosis by mouse melanoma B16 cell and exhibited higher induced apoptosis although with little dark toxicity. RB−MMSNs had little dark toxicity and even much could be facilitated by magnetic field in vitro. RB−MMSNs demonstrated 10 times induced apoptosis efficiency than that of free RB at the same RB concentration, both by cell counting kit-8 (CCK-8) result and apoptosis detection. Furthermore, RB−MMSNs-mediated PDT in vivo on tumor-bearing mice showed steady physical targeting of RB−MMSNs to the tumor site; tumor volumes were significantly reduced in the magnetic field with green light irradiation. More importantly, the survival time of tumor-bearing mice treated with RB−MMSNs was much prolonged. Henceforth, polyethylene glycol- b -polyaspartate-modified magnetic mesoporous silica (MMSNs) probably have great potential in clinical cancer photodynamic treatment because of their effective and low-toxic performance as photosensitizers’ vesicles.

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“…The versatility of ION surface coatings has also promoted the selective magnetic labeling and tracking of cells within co-culture [ 16 ] or in vivo [ 17 ] studies. In particular, they have been employed as contrast agents for magnetic resonance imaging (MRI) [ 18 , 19 ], since their notable paramagnetic behavior grants superior transverse relaxivity (T 2 ) than that of surrounding tissues and, in turn, creates a negative image contrast where they are located [ 20 ]. Besides medical imaging, the exceptional magnetization of functionalized IONs has allowed the magnetic separation of specimens (e.g., bacteria, viruses, macromolecules, cancer cells) for disease diagnosis [ 21 ] and the controlled migration [ 22 ] and sorting [ 23 ] of labeled cells both in vitro and in vivo.…”

Section: Introductionmentioning

confidence: 99%

Tailoring Iron Oxide Nanoparticles for Efficient Cellular Internalization and Endosomal Escape

et al. 2020

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Iron oxide nanoparticles (IONs) have been widely explored for biomedical applications due to their high biocompatibility, surface-coating versatility, and superparamagnetic properties. Upon exposure to an external magnetic field, IONs can be precisely directed to a region of interest and serve as exceptional delivery vehicles and cellular markers. However, the design of nanocarriers that achieve an efficient endocytic uptake, escape lysosomal degradation, and perform precise intracellular functions is still a challenge for their application in translational medicine. This review highlights several aspects that mediate the activation of the endosomal pathways, as well as the different properties that govern endosomal escape and nuclear transfection of magnetic IONs. In particular, we review a variety of ION surface modification alternatives that have emerged for facilitating their endocytic uptake and their timely escape from endosomes, with special emphasis on how these can be manipulated for the rational design of cell-penetrating vehicles. Moreover, additional modifications for enhancing nuclear transfection are also included in the design of therapeutic vehicles that must overcome this barrier. Understanding these mechanisms opens new perspectives in the strategic development of vehicles for cell tracking, cell imaging and the targeted intracellular delivery of drugs and gene therapy sequences and vectors.

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Increased transverse relaxivity in ultrasmall superparamagnetic iron oxide nanoparticles used as MRI contrast agent for biomedical imaging

Cited by 40 publications

References 48 publications

Photoacoustic and Magnetic Resonance Imaging Bimodal Contrast Agent Displaying Amplified Photoacoustic Signal

Photoacoustic and Magnetic Resonance Imaging Bimodal Contrast Agent Displaying Amplified Photoacoustic Signal

Magnetic and pH dual-responsive mesoporous silica nanocomposites for effective and low-toxic photodynamic therapy

Tailoring Iron Oxide Nanoparticles for Efficient Cellular Internalization and Endosomal Escape

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