scholarly journals Emerging Applications of Porphyrins and Metalloporphyrins in Biomedicine and Diagnostic Magnetic Resonance Imaging

Biosensors ◽  
2018 ◽  
Vol 8 (4) ◽  
pp. 95 ◽  
Author(s):  
Muhammad Imran ◽  
Muhammad Ramzan ◽  
Ahmad Qureshi ◽  
Muhammad Khan ◽  
Muhammad Tariq

In recent years, scientific advancements have constantly increased at a significant rate in the field of biomedical science. Keeping this in view, the application of porphyrins and metalloporphyrins in the field of biomedical science is gaining substantial importance. Porphyrins are the most widely studied tetrapyrrole-based compounds because of their important roles in vital biological processes. The cavity of porphyrins containing four pyrrolic nitrogens is well suited for the binding majority of metal ions to form metalloporphyrins. Porphyrins and metalloporphyrins possess peculiar photochemical, photophysical, and photoredox properties which are tunable through structural modifications. Their beneficial photophysical properties, such as the long wavelength of emission and absorption, high singlet oxygen quantum yield, and low in vivo toxicity, have drawn scientists’ interest to discover new dimensions in the biomedical field. Applications of porphyrins and metalloporphyrins have been pursued in the perspective of contrast agents for magnetic resonance imaging (MRI), photodynamic therapy (PDT) of cancer, bio-imaging, and other biomedical applications. This review discusses photophysics and the photochemistry of porphyrins and their metal complexes. Secondly, it explains the current developments and mode of action for contrast agents for MRI. Moreover, the application of porphyrin and metalloporphyrin-based molecules as a photosensitizer in PDT of cancer, the mechanism of the generation of reactive oxygen species (ROS), factors that determine the efficiency of PDT, and the developments to improve this technology are delineated. The last part explores the most recent research and developments on metalloporphyrin-based materials in bio-imaging, drug delivery, and the determination of ferrochelatase in bone marrow indicating their prospective clinical applications.

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.


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.


2018 ◽  
Vol 25 (25) ◽  
pp. 2910-2937 ◽  
Author(s):  
Guangyue Zu ◽  
Ye Kuang ◽  
Jingjin Dong ◽  
Yi Cao ◽  
Tingting Zhang ◽  
...  

Contrast agents (CAs) are widely used to improve the signal-noise ratio in the magnetic resonance imaging (MRI) examinations. The majority of MRI CAs used in clinic are gadolinium( III) (Gd(III)) chelates with low molecular weight. Compared with these small-molecule CAs, Gd(III)-based polymeric magnetic resonance imaging agents (i.e. macromolecular contrast agents, mCAs), prepared by conjugating small-molecule Gd(III) chelates onto macromolecules, possess high relaxivity and relative long blood circulation time, which are favorable for MRI examinations. In last decades, increasing attention was paid to the design of mCAs with various structures, and further evaluation of the MRI performance both in vitro and in vivo. Herein, we focus on the recent progress of mCAs, including structures, properties and applications. Meanwhile, this review also highlights the emerging MRI mCAs with smart response and multi-function: tumor microenvironment- stimulated MRI, multi-mode imaging and MRI-based theranostics.


2019 ◽  
Author(s):  
Hamilton Lee ◽  
Jenica Lumata ◽  
Michael A. Luzuriaga ◽  
Candace Benjamin ◽  
Olivia Brohlin ◽  
...  

<div><div><div><p>Many contrast agents for magnetic resonance imaging are based on gadolinium, however side effects limit their use in some patients. Organic radical contrast agents (ORCAs) are potential alternatives, but are reduced rapidly in physiological conditions and have low relaxivities as single molecule contrast agents. Herein, we use a supramolecular strategy where cucurbit[8]uril binds with nanomolar affinities to ORCAs and protects them against biological reductants to create a stable radical in vivo. We further over came the weak contrast by conjugating this complex on the surface of a self-assembled biomacromolecule derived from the tobacco mosaic virus.</p></div></div></div>


2005 ◽  
Vol 2 (2) ◽  
pp. 133-140 ◽  
Author(s):  
D. Mietchen ◽  
H. Keupp ◽  
B. Manz ◽  
F. Volke

Abstract. For more than a decade, Magnetic Resonance Imaging (MRI) has been routinely employed in clinical diagnostics because it allows non-invasive studies of anatomical structures and physiological processes in vivo and to differentiate between healthy and pathological states, particularly of soft tissue. Here, we demonstrate that MRI can likewise be applied to fossilized biological samples and help in elucidating paleopathological and paleoecological questions: Five anomalous guards of Jurassic and Cretaceous belemnites are presented along with putative paleopathological diagnoses directly derived from 3D MR images with microscopic resolution. Syn vivo deformities of both the mineralized internal rostrum and the surrounding former soft tissue can be traced back in part to traumatic events of predator-prey-interactions, and partly to parasitism. Besides, evidence is presented that the frequently observed anomalous apical collar might be indicative of an inflammatory disease. These findings highlight the potential of Magnetic Resonance techniques for further paleontological applications.


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 10 (11) ◽  
pp. 2461
Author(s):  
José María Mora-Gutiérrez ◽  
María A. Fernández-Seara ◽  
Rebeca Echeverria-Chasco ◽  
Nuria Garcia-Fernandez

Renal magnetic resonance imaging (MRI) techniques are currently in vogue, as they provide in vivo information on renal volume, function, metabolism, perfusion, oxygenation, and microstructural alterations, without the need for exogenous contrast media. New imaging biomarkers can be identified using these tools, which represent a major advance in the understanding and study of the different pathologies affecting the kidney. Diabetic kidney disease (DKD) is one of the most important diseases worldwide due to its high prevalence and impact on public health. However, its multifactorial etiology poses a challenge for both basic and clinical research. Therefore, the use of novel renal MRI techniques is an attractive step forward in the comprehension of DKD, both in its pathogenesis and in its detection and surveillance in the clinical practice. This review article outlines the most promising MRI techniques in the study of DKD, with the purpose of stimulating their clinical translation as possible tools for the diagnosis, follow-up, and monitoring of the clinical impacts of new DKD treatments.


RSC Advances ◽  
2016 ◽  
Vol 6 (23) ◽  
pp. 18843-18851 ◽  
Author(s):  
N. Venkatesha ◽  
Yasrib Qurishi ◽  
Hanudatta S. Atreya ◽  
Chandan Srivastava

The potential of CoFe2O4–ZnO core–shell nanoparticles for fluorescence optical imaging and as a contrast agent for magnetic resonance imaging (MRI) is demonstrated.


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