scholarly journals In Vivo Potential of Manganese Chelated Porphysomes as MRI Contrast Agents

2017 ◽  
Vol 3 (1) ◽  
pp. 47-53 ◽  
Author(s):  
Chris J. Zhang ◽  
Michael S. Valic ◽  
Juan Chen ◽  
Gang Zheng

Porphysome nanoparticles are composed of porphyrin-conjugated lipids. The attachment of the porphyrin moiety to each phospholipid confers novel properties to the liposome-like nanoparticle, allowing it to perform a variety of diagnostic and therapeutic applications. The metal chelating properties of porphyrin can be used to bind manganese (Mn), transforming the porphysome into a contrast agent for magnetic resonance imaging (MRI). Previous work has extensively characterized the properties of the Mn-porphysome. Herein, we build upon that work by demonstrating the bio-interactions of Mn-porphysomes in vitro to validate their study in vivo. Particle stability in serum was inferred from fluorescence quenching efficiency, and tolerability to cells was measured using an MTT assay. Mn-porphysomes remained >80% quenched after 14H and showed no toxicity to cells at concentrations below 125 mM. These preliminary results suggest that the porphysome may be used to enhance MRI contrast in vivo.

2020 ◽  
Vol 11 ◽  
pp. 1000-1009
Author(s):  
Miao Qin ◽  
Yueyou Peng ◽  
Mengjie Xu ◽  
Hui Yan ◽  
Yizhu Cheng ◽  
...  

The multimodal magnetic resonance imaging (MRI) technique has been extensively studied over the past few years since it offers complementary information that can increase diagnostic accuracy. Simple methods to synthesize contrast agents are necessary for the development of multimodal MRI. Herein, uniformly distributed Fe3O4/Gd2O3 nanocubes for T 1–T 2 dual-mode MRI contrast agents were successfully designed and synthesized. In order to increase hydrophilicity and biocompatibility, the nanocubes were coated with nontoxic 3,4-dihydroxyhydrocinnamic acid (DHCA). The results show that iron (Fe) and gadolinium (Gd) were homogeneously distributed throughout the Fe3O4/Gd2O3-DHCA (FGDA) nanocubes. Relaxation time analysis was performed on the images obtained from the 3.0 T scanner. The results demonstrated that r 1 and r 2 maximum values were 67.57 ± 6.2 and 24.2 ± 1.46 mM−1·s−1, respectively. In vivo T 1- and T 2-weighted images showed that FGDA nanocubes act as a dual-mode contrast agent enhancing MRI quality. Overall, these experimental results suggest that the FGDA nanocubes are interesting tools that can be used to increase MRI quality, enabling accurate clinical diagnostics.


2011 ◽  
Vol 2011 ◽  
pp. 1-11 ◽  
Author(s):  
Hyeona Yim ◽  
Seogjin Seo ◽  
Kun Na

Various imaging technologies have become increasingly important in developing a better understanding of information on the biological and clinical phenomena associated with diseases of interest. Of these technologies, magnetic resonance imaging (MRI) is one of the most powerful for clinical diagnosis and in vivo imaging without the exposure to ionising radiation or radiotracers. Despite its many advantages, there are intrinsic limitations caused by MRI contrast agents, such as short vascular half-life circulation, which lead to unwanted side effects. In this review, we will focus on the multifunctional modification of MRI contrast agents for diagnosis and therapy.


2017 ◽  
Vol 8 (11) ◽  
pp. 7631-7636 ◽  
Author(s):  
B. W. Roose ◽  
S. D. Zemerov ◽  
I. J. Dmochowski

Genetically encoded magnetic resonance imaging (MRI) contrast agents enable non-invasive detection of specific biomarkersin vivo.


2019 ◽  
Author(s):  
Simone Schuerle ◽  
Maiko Furubayashi ◽  
Ava P. Soleimany ◽  
Tinotenda Gwisai ◽  
Wei Huang ◽  
...  

AbstractTumor-selective contrast agents have the potential to aid in the diagnosis and treatment of cancer using noninvasive imaging modalities such as magnetic resonance imaging (MRI). Such contrast agents can consist of magnetic nanoparticles incorporating functionalities that respond to cues specific to tumor environments. Genetically engineering magnetotactic bacteria to display peptides has been investigated as a means to produce contrast agents that combine the robust image contrast effects of magnetosomes with transgenic targeting peptides displayed on their surface. This work reports the first use of magnetic nanoparticles that display genetically-encoded pH low insertion peptide (pHLIP), a long peptide intended to enhance MRI contrast by targeting the extracellular acidity associated with the tumors. To demonstrate the modularity of this versatile platform to incorporate diverse targeting ligands by genetic engineering, we also incorporated the cyclic αv integrin-binding peptide iRGD into separate magnetosomes. Specifically, we investigate their potential for enhanced binding and tumor imaging both in vitro and in vivo. Our experiments indicate that these tailored magnetosomes retain their magnetic properties, making them well-suited as T2 contrast agents, while exhibiting increased binding compared to wild-type magnetosomes.


2016 ◽  
Vol 4 (45) ◽  
pp. 7241-7248 ◽  
Author(s):  
Qin Zhu ◽  
Heng Yang ◽  
Yuanyuan Li ◽  
Yu Tian ◽  
Wei Wang ◽  
...  

HP-DO3A-based amphiphilic magnetic resonance imaging (MRI) contrast agents show electrostatic self-assembly ability with polyelectrolytes, good biocompatibility, and significant contrast enhancement in in vivo imaging.


2017 ◽  
Vol 70 (3) ◽  
pp. 307 ◽  
Author(s):  
Youyang Zhan ◽  
Rong Xue ◽  
Mengchao Zhang ◽  
Chuanling Wan ◽  
Xiaojing Li ◽  
...  

A new macromolecular biocompatible gadolinium chelate complex (PAI-N2-DOTA-Gd) as a liver-specific magnetic resonance imaging (MRI) contrast agent was synthesised and evaluated. An aspartic acid–isoleucine copolymer was chemically linked with Gd-DOTA via ethylenediamine to give PAI-N2-DOTA-Gd. In vitro, the T1-relaxivity of PAI-N2-DOTA-Gd (14.38 mmol–1⋅L⋅s–1, 0.5 T) was much higher than that of the clinically used Gd-DOTA (4.96 mmol–1⋅L⋅s–1, 0.5 T), with obvious imaging signal enhancement. In the imaging experiments in vivo, PAI-N2-DOTA-Gd exhibited good liver selectivity, and had a greater intensity enhancement (68.8 ± 5.6 %) and a longer imaging window time (30–70 min), compared to Gd-DOTA (21.1 ± 5.3 %, 10–30 min). Furthermore, the in vivo histological studies of PAI-N2-DOTA-Gd showed a low acute toxicity and desirable biocompatibility. The results of this study indicate that PAI-N2-DOTA-Gd is a feasible liver-specific contrast agent for MRI.


Nanomaterials ◽  
2020 ◽  
Vol 10 (11) ◽  
pp. 2249
Author(s):  
Romy Mueller ◽  
Michele Moreau ◽  
Sayeda Yasmin-Karim ◽  
Andrea Protti ◽  
Olivier Tillement ◽  
...  

Smart radiotherapy biomaterials (SRBs) present a new opportunity to enhance image-guided radiotherapy while replacing routinely used inert radiotherapy biomaterials like fiducials. In this study the potential of SRBs loaded with gadolinium-based nanoparticles (GdNPs) is investigated for magnetic resonance imaging (MRI) contrast. GdNP release from SRB is quantified and modelled for accurate prediction. SRBs were manufactured similar to fiducials, with a cylindrical shell consisting of poly(lactic-co-glycolic) acid (PLGA) and a core loaded with GdNPs. Magnetic resonance imaging (MRI) contrast was investigated at 7T in vitro (in agar) and in vivo in subcutaneous tumors grown with the LLC1 lung cancer cell line in C57/BL6 mice. GdNPs were quantified in-phantom and in tumor and their release was modelled by the Weibull distribution. Gd concentration was linearly fitted to the R1 relaxation rate with a detection limit of 0.004 mmol/L and high confidence level (R2 = 0.9843). GdNP loaded SRBs in tumor were clearly visible up to at least 14 days post-implantation. Signal decrease during this time showed GdNP release in vivo, which was calculated as 3.86 ± 0.34 µg GdNPs release into the tumor. This study demonstrates potential and feasibility for SRBs with MRI-contrast, and sensitive GdNP quantification and release from SRBs in a preclinical animal model. The feasibility of monitoring nanoparticle (NP) concentration during treatment, allowing dynamic quantitative treatment planning, is also discussed.


Author(s):  
Anton Popov ◽  
Maxim Artemovich Abakumov ◽  
Irina Savintseva ◽  
Artem Ermakov ◽  
Nelly Popova ◽  
...  

Gd-based complexes are widely used as magnetic resonance imaging (MRI) contrast agents. The safety of previously approved contrast agents is questionable and is being re-assessed. The main causes of concern...


2021 ◽  
Vol 11 (3) ◽  
pp. 1165
Author(s):  
Wen-Tien Hsiao ◽  
Yi-Hong Chou ◽  
Jhong-Wei Tu ◽  
Ai-Yih Wang ◽  
Lu-Han Lai

The purpose of this study is to establish the minimal injection doses of magnetic resonance imaging (MRI) contrast agents that can achieve optimized images while improving the safety of injectable MRI drugs. Gadolinium-diethylenetriamine penta-acetic acid (Gd-DTPA) and ferucarbotran, commonly used in clinical practice, were selected and evaluated with in vitro and in vivo experiments. MRI was acquired using T1-weighted (T1W) and T2-weighted (T2W) sequences, and the results were quantitatively analyzed. For in vitro experiments, results showed that T1W and T2W images were optimal when Gd-DTPA-bisamide (2-oxoethyl) (Gd-DTPA-BMEA) and ferucarbotran were diluted to a volume percentage of 0.6% and 0.05%; all comparisons were significant differences in grayscale statistics using one-way analysis of variance (ANOVA). For in vivo experiments, the contrast agent with optimal concentration percentages determined from in vitro experiments were injected into mice with an injection volume of 100 μL, and the images of brain, heart, liver, and mesentery before and after injection were compared. The statistical results showed that the p values of both T1W and T2W were less than 0.001, which were statistically significant. Under safety considerations for MRI contrast agent injection, optimized MRI images could still be obtained after reducing the injection concentration, which can provide a reference for the safety concentrations of MRI contrast agent injection in the future.


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