Renal-clearable zwitterionic conjugated hollow ultrasmall Fe3O4 nanoparticles for T1-weighted MR imaging in vivo

2020 ◽  
Vol 8 (15) ◽  
pp. 3087-3091
Author(s):  
Wei Liu ◽  
Guang Deng ◽  
Danli Wang ◽  
Ming Chen ◽  
Zhiguo Zhou ◽  
...  

Monodispersed hollow Fe3O4 nanoparticles with the diameters of 7 and 10 nm were prepared via a high-temperature pyrolysis method and the Kirkendall effect by regulating the ratio of oleylamine to oleic acid.

2020 ◽  
Vol 20 (16) ◽  
pp. 1918-1926
Author(s):  
Fahimeh H. Beigi ◽  
Soheil Fatahian ◽  
Sogand Shahbazi-Gahrouei ◽  
Daryoush Shahbazi-Gahrouei ◽  
Amin Farzadniya

Objective: Polydopamine coated iron oxide nanoparticles (Fe3O4@PDA NPs) were synthesized, characterized, and their MR imaging contrast agents and photothermal potency were evaluated on melanoma (B16-F10 and A-375) cells and normal skin cells. To this end, MTT assay, Fe concentration, and MR imaging of both coated and uncoated NPs were assessed in C57BL/6 mice. Methods: Fe3O4 nanoparticles were synthesized using co-precipitation, and coated with polydopamine. The cytotoxicity of Fe3O4 and Fe3O4@PDA NPs on melanoma cells, with different concentrations, were obtained using MTT assay. MR images and Fe concentrations of nanoprobe and nanoparticles were evaluated under in vivo conditions. Results: Findings indicated that uncoated Fe3O4 showed the highest toxicity in animal (B16-F10) cells at 450μg/ml after 72h, while the highest toxicity in human (A-375) cells were observed at 350μg/ml. These nanoparticles did not reveal any cytotoxicity to normal skin cells, despite having some toxicity features in A-375 cells. MR image signals in the tumor were low compared with other tissues. The iron concentration in the tumor was higher than that of other organs. Conclusion: It is concluded that the cytotoxicity of Fe3O4@PDA was found to be significantly lower than uncoated nanoparticles (p <0.001), which allows some positive effects on reducing toxicity. The prepared nanoprobe may be used as a contrast agent in MR imaging.


2017 ◽  
Vol 9 (21) ◽  
pp. 3099-3104 ◽  
Author(s):  
Dong Li ◽  
Minghui Hua ◽  
Kun Fang ◽  
Rong Liang

Bovine serum albumin-Fe3O4 nanoparticles with undoubted biosafety and robust dual-modal T1 and T2 MR imaging ability were fabricated using a biomineralization approach in a facile way under mild conditions for in vivo MR imaging.


Author(s):  
Junchao Qian ◽  
Xiang Yu ◽  
Bingbing Li ◽  
Zhenle Fei ◽  
Xiang Huang ◽  
...  

Background:: It was known that the response of tumor cells to radiation is closely related to tissue oxygen level and fractionated radiotherapy allows reoxygenation of hypoxic tumor cells. Non-invasive mapping of tissue oxygen level may hold great importance in clinic. Objective: The aim of this study is to evaluate the role of oxygen-enhanced MR imaging in the detection of tissue oxygen levels between fractionated radiotherapy. Methods: A cohort of 10 patients with brain metastasis was recruited. Quantitative oxygen enhanced MR imaging was performed prior to, 30 minutes and 22 hours after first fractionated radiotherapy. Results: The ΔR1 (the difference of longitudinal relaxivity between 100% oxygen breathing and air breathing) increased in the ipsilateral tumor site and normal tissue by 242% and 152%, respectively, 30 minutes after first fractionated radiation compared to pre-radiation levels. Significant recovery of ΔR1 in the contralateral normal tissue (p < 0.05) was observed 22 hours compared to 30 minutes after radiation levels. Conclusion: R1-based oxygen-enhanced MR imaging may provide a sensitive endogenous marker for oxygen changes in the brain tissue between fractionated radiotherapy.


BMC Genomics ◽  
2021 ◽  
Vol 22 (1) ◽  
Author(s):  
Vengala Rao Yenuganti ◽  
Dirk Koczan ◽  
Jens Vanselow

Abstract Background Metabolic stress, as negative energy balance on one hand or obesity on the other hand can lead to increased levels of free fatty acids in the plasma and follicular fluid of animals and humans. In an earlier study, we showed that increased oleic acid (OA) concentrations affected the function of cultured bovine granulosa cells (GCs). Here, we focus on genome wide effects of increased OA concentrations. Results Our data showed that 413 genes were affected, of which 197 were down- and 216 up-regulated. Specifically, the expression of FSH-regulated functional key genes, CCND2, LHCGR, INHA and CYP19A1 and 17-β-estradiol (E2) production were reduced by OA treatment, whereas the expression of the fatty acid transporter CD36 was increased and the morphology of the cells was changed due to lipid droplet accumulation. Bioinformatic analysis revealed that associated pathways of the putative upstream regulators “FSH” and “Cg (choriogonadotropin)” were inhibited and activated, respectively. Down-regulated genes are over-represented in GO terms “reproductive structure/system development”, “ovulation cycle process”, and “(positive) regulation of gonadotropin secretion”, whereas up-regulated genes are involved in “circulatory system development”, “vasculature development”, “angiogenesis” or “extracellular matrix/structure organization”. Conclusions From these data we conclude that besides inhibiting GC functionality, increased OA levels seemingly promote angiogenesis and tissue remodelling, thus suggestively initiating a premature fulliculo-luteal transition. In vivo this may lead to impeded folliculogenesis and ovulation, and cause sub-fertility.


Author(s):  
Pietro Canzi ◽  
Marianna Magnetto ◽  
Anna Simoncelli ◽  
Marco Manfrin ◽  
Federico Aprile ◽  
...  

Abstract Purposes To investigate the effects for Ultra 3D cochlear implant (CI) positioning on MR imaging quality, looking at a comprehensive description of intracranial structures in cases of unilateral and bilateral CI placement. Methods Four CI angular positions (90°, 120°, 135° and 160°) at 9 cm distance from the outer-ear canal were explored. The 1.5 T MRI assessment included our institutional protocol for the investigation of brain pathologies without gadolinium application. Three investigators (two experienced neuroradiologists and one experienced otoneurosurgeon) independently evaluated the MR findings. A 4-point scale was adopted to describe 14 intracranial structures and to determine which CI positioning allowed the best image quality score and how bilateral CI placement modified MRI scan visibility. Results A high positive correlation was found between the three blinded observers. Structures situated contralateral from the CI showed high-quality values in all four placements. Structures situated ipsilaterally provided results suitable for diagnostic purposes for at least one position. At 90°, artifacts mainly involved brain structures located cranially and anteriorly (e.g., temporal lobe); on the contrary, at 160°, artifacts mostly influenced the posterior fossa structures (e.g., occipital lobe). For the bilateral CI condition, MR imaging examination revealed additional artifacts involving all structures located close to either CI, where there was a signal void/distortion area. Conclusions Suitable unilateral CI positioning can allow the visualization of intracranial structures with sufficient visibility for diagnostic purposes. Bilateral CI positioning significantly deteriorates the anatomical visibility. CI positioning might play a crucial role for patients who need post-operative MRI surveillance.


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