Covalent functionalization of multi-walled carbon nanotubes with a gadolinium chelate for efficient T1-weighted magnetic resonance imaging

Given the promise of carbon nanotubes (CNTs) for photothermal therapy, drug delivery, tissue engineering, and gene therapy, there is a need for non-invasive imaging methods to monitor CNT distribution and fate in the body. In this study, non-ionizing whole-body high field magnetic resonance imaging (MRI) is used to follow the distribution of water-dispersible non-toxic functionalized CNTs administrated intravenously to mice. Oxidized CNTs are endowed with positive MRI contrast properties by covalent functionalization with the chelating ligand diethylenetriaminepentaacetic dianhydride (DTPA), followed by chelation to Gd. The structural and magnetic properties, MR relaxivities, cellular uptake, and application for MRI cell imaging of Gd-CNTs in comparison to the precursor oxidized CNTs are evaluated. Despite the intrinsic T contrast of oxidized CNTs internalized in macrophages, the anchoring of paramagnetic gadolinium onto the nanotube sidewall allows efficient T contrast and MR signal enhancement, which is preserved after CNT internalization by cells. Hence, due to their high dispersibility, Gd-CNTs have the potential to produce positive contrast in vivo following injection into the bloodstream. The uptake of Gd-CNTs in the liver and spleen is assessed using MRI, while rapid renal clearance of extracellular Gd-CNTs is observed, confirming the evidences of other studies using different imaging modalities

Elastomeric cardiopatch scaffold for myocardial repair and ventricular support

[EN] OBJECTIVES: Prevention of postischaemic ventricular dilatation progressing towards pathological remodelling is necessary to decrease ventricular wall deterioration. Myocardial tissue engineering may play a therapeutic role due to its capacity to replace the extracellular matrix, thereby creating niches for cell homing. In this experimental animal study, a biomimetic cardiopatch was created with elastomeric scaffolds and nanotechnologies. METHODS: In an experimental animal study in 18 sheep, a cardiopatch was created with adipose tissue-derived progenitor cells seeded into an engineered bioimplant consisting of 3-dimensional bioabsorbable polycaprolactone scaffolds filled with a peptide hydrogel (PuraMatrix (TM)). This patch was then transplanted to cover infarcted myocardium. Non-absorbable poly(ethyl) acrylate polymer scaffolds were used as controls. RESULTS: Fifteen sheep were followed with ultrasound scans at 6 months, including echocardiography scans, tissue Doppler and spectral flow analysis and speckle-tracking imaging, which showed a reduction in longitudinal left ventricular deformation in the cardiopatch-treated group. Magnetic resonance imaging (late gadolinium enhancement) showed reduction of infarct size relative to left ventricular mass in the cardiopatch group versus the controls. Histopathological analysis at 6 months showed that the cardiopatch was fully anchored and integrated to the infarct area with minimal fibrosis interface, thereby promoting angiogenesis and migration of adipose tissue-derived progenitor cells to surrounding tissues. CONCLUSIONS: This study shows the feasibility and effectiveness of a cardiopatch grafted onto myocardial infarction scars in an experimental animal model. This treatment decreased fibrosis, limited infarct scar expansion and reduced postischaemic ventricular deformity. A capillary network developed between our scaffold and the heart. The elastomeric cardiopatch seems to have a positive impact on ventricular remodelling and performance in patients with heart failure.The RECATABI Project (Regeneration of Cardiac Tissue Assisted by Bioactive Implants) was financially supported by the 7th Framework Programme (FP7) of the European Commission. Project ID: 229239. Funded under FP7-NMP and the European Regional Development Fund (FEDER Spain).Chachques, JC.; Lila, N.; Soler Botija, C.; Martínez-Ramos, C.; Vallés Lluch, A.; Autret, G.; Perier, M.... (2020). Elastomeric cardiopatch scaffold for myocardial repair and ventricular support. European Journal of Cardio-Thoracic Surgery. 57(3):545-555. https://doi.org/10.1093/ejcts/ezz252S545555573Madonna, R., Van Laake, L. W., Botker, H. E., Davidson, S. M., De Caterina, R., Engel, F. B., … Sluijter, J. P. G. (2019). ESC Working Group on Cellular Biology of the Heart: position paper for Cardiovascular Research: tissue engineering strategies combined with cell therapies for cardiac repair in ischaemic heart disease and heart failure. Cardiovascular Research, 115(3), 488-500. doi:10.1093/cvr/cvz010Nielsen, S. H., Mouton, A. J., DeLeon-Pennell, K. Y., Genovese, F., Karsdal, M., & Lindsey, M. L. (2019). Understanding cardiac extracellular matrix remodeling to develop biomarkers of myocardial infarction outcomes. Matrix Biology, 75-76, 43-57. doi:10.1016/j.matbio.2017.12.001Spinale, F. G., Frangogiannis, N. G., Hinz, B., Holmes, J. W., Kassiri, Z., & Lindsey, M. L. (2016). Crossing Into the Next Frontier of Cardiac Extracellular Matrix Research. Circulation Research, 119(10), 1040-1045. doi:10.1161/circresaha.116.309916Chachques, J. C., Pradas, M. M., Bayes-Genis, A., & Semino, C. (2013). Creating the bioartificial myocardium for cardiac repair: challenges and clinical targets. Expert Review of Cardiovascular Therapy, 11(12), 1701-1711. doi:10.1586/14779072.2013.854165Bayés-Genís, A., Gálvez-Montón, C., & Roura, S. (2016). Cardiac Tissue Engineering. Journal of the American College of Cardiology, 68(7), 724-726. doi:10.1016/j.jacc.2016.05.055Shafy, A., Fink, T., Zachar, V., Lila, N., Carpentier, A., & Chachques, J. C. (2012). Development of cardiac support bioprostheses for ventricular restoration and myocardial regeneration. European Journal of Cardio-Thoracic Surgery, 43(6), 1211-1219. doi:10.1093/ejcts/ezs480Castells-Sala, C., Recha-Sancho, L., Llucià-Valldeperas, A., Soler-Botija, C., Bayes-Genis, A., & Semino, C. E. (2016). Three-Dimensional Cultures of Human Subcutaneous Adipose Tissue-Derived Progenitor Cells Based on RAD16-I Self-Assembling Peptide. Tissue Engineering Part C: Methods, 22(2), 113-124. doi:10.1089/ten.tec.2015.0270Martínez-Ramos, C., Rodríguez-Pérez, E., Garnes, M. P., Chachques, J. C., Moratal, D., Vallés-Lluch, A., & Monleón Pradas, M. (2014). Design and Assembly Procedures for Large-Sized Biohybrid Scaffolds as Patches for Myocardial Infarct. Tissue Engineering Part C: Methods, 20(10), 817-827. doi:10.1089/ten.tec.2013.0489Biswas, M., Sudhakar, S., Nanda, N. C., Buckberg, G., Pradhan, M., Roomi, A. U., … Houle, H. (2013). Two- and Three-Dimensional Speckle Tracking Echocardiography: Clinical Applications and Future Directions. Echocardiography, 30(1), 88-105. doi:10.1111/echo.12079Dorsey, S. M., McGarvey, J. R., Wang, H., Nikou, A., Arama, L., Koomalsingh, K. J., … Burdick, J. A. (2015). MRI evaluation of injectable hyaluronic acid-based hydrogel therapy to limit ventricular remodeling after myocardial infarction. Biomaterials, 69, 65-75. doi:10.1016/j.biomaterials.2015.08.011Chachques, J. C. (2009). Cellular cardiac regenerative therapy in which patients? Expert Review of Cardiovascular Therapy, 7(8), 911-919. doi:10.1586/erc.09.84Chachques, J. (1997). Dynamic cardiomyoplasty: clinical follow-up at 12 years. European Journal of Cardio-Thoracic Surgery, 12(4), 560-568. doi:10.1016/s1010-7940(97)00214-5Varela, C. E., Fan, Y., & Roche, E. T. (2019). Optimizing Epicardial Restraint and Reinforcement Following Myocardial Infarction: Moving Towards Localized, Biomimetic, and Multitherapeutic Options. Biomimetics, 4(1), 7. doi:10.3390/biomimetics4010007Van den Borne, S. W. M., Cleutjens, J. P. M., Hanemaaijer, R., Creemers, E. E., Smits, J. F. M., Daemen, M. J. A. P., & Blankesteijn, W. M. (2009). Increased matrix metalloproteinase-8 and -9 activity in patients with infarct rupture after myocardial infarction. Cardiovascular Pathology, 18(1), 37-43. doi:10.1016/j.carpath.2007.12.012Ducharme, A., Frantz, S., Aikawa, M., Rabkin, E., Lindsey, M., Rohde, L. E., … Lee, R. T. (2000). Targeted deletion of matrix metalloproteinase-9 attenuates left ventricular enlargement and collagen accumulation after experimental myocardial infarction. Journal of Clinical Investigation, 106(1), 55-62. doi:10.1172/jci8768Sieminski, A. L., Semino, C. E., Gong, H., & Kamm, R. D. (2008). Primary sequence of ionic self-assembling peptide gels affects endothelial cell adhesion and capillary morphogenesis. Journal of Biomedical Materials Research Part A, 87A(2), 494-504. doi:10.1002/jbm.a.31785Bagó, J. R., Soler-Botija, C., Casaní, L., Aguilar, E., Alieva, M., Rubio, N., … Blanco, J. (2013). Bioluminescence imaging of cardiomyogenic and vascular differentiation of cardiac and subcutaneous adipose tissue-derived progenitor cells in fibrin patches in a myocardium infarct model. International Journal of Cardiology, 169(4), 288-295. doi:10.1016/j.ijcard.2013.09.013Chachques, J. C., Trainini, J. C., Lago, N., Cortes-Morichetti, M., Schussler, O., & Carpentier, A. (2008). Myocardial Assistance by Grafting a New Bioartificial Upgraded Myocardium (MAGNUM Trial): Clinical Feasibility Study. The Annals of Thoracic Surgery, 85(3), 901-908. doi:10.1016/j.athoracsur.2007.10.052Lee, H., Ahn, S., Bonassar, L. J., & Kim, G. (2012). Cell(MC3T3-E1)-Printed Poly(ϵ-caprolactone)/Alginate Hybrid Scaffolds for Tissue Regeneration. Macromolecular Rapid Communications, 34(2), 142-149. doi:10.1002/marc.201200524Strub, M., Van Bellinghen, X., Fioretti, F., Bornert, F., Benkirane-Jessel, N., Idoux-Gillet, Y., … Clauss, F. (2018). Maxillary Bone Regeneration Based on Nanoreservoirs Functionalizedε-Polycaprolactone Biomembranes in a Mouse Model of Jaw Bone Lesion. BioMed Research International, 2018, 1-12. doi:10.1155/2018/7380389Rohman, G., Huot, S., Vilas-Boas, M., Radu-Bostan, G., Castner, D. G., & Migonney, V. (2015). The grafting of a thin layer of poly(sodium styrene sulfonate) onto poly(ε-caprolactone) surface can enhance fibroblast behavior. Journal of Materials Science: Materials in Medicine, 26(7). doi:10.1007/s10856-015-5539-7Spadaccio, C., Nappi, F., De Marco, F., Sedati, P., Taffon, C., Nenna, A., … Rainer, A. (2017). Implantation of a Poly-l-Lactide GCSF-Functionalized Scaffold in a Model of Chronic Myocardial Infarction. Journal of Cardiovascular Translational Research, 10(1), 47-65. doi:10.1007/s12265-016-9718-9Monnet, E., & Chachques, J. C. (2005). Animal Models of Heart Failure: What Is New? The Annals of Thoracic Surgery, 79(4), 1445-1453. doi:10.1016/j.athoracsur.2004.04.002Bellin, G., Gardin, C., Ferroni, L., Chachques, J., Rogante, M., Mitrečić, D., … Zavan, B. (2019). Exosome in Cardiovascular Diseases: A Complex World Full of Hope. Cells, 8(2), 166. doi:10.3390/cells802016

Spatially broad opening of the blood-brain barrier with an unfocused ultrasound transducer in rabbits

International audienceThe aim of this work was to study the opening of the blood-brain barrier (BBB) over a large volume using an unfocused ultrasound device in the presence of ultrasound contrast agents in rabbits. A mono-element planar 1MHz ultrasound transducer was used to perform burst sonications in 24 healthy New-Zealand white rabbits after craniectomy and during intravenous injection of Sonovue®. The transducer was operated with a pulse repetition frequency of 1Hz, and a range of pulses lengths and in situ acoustic pressures (10-35ms and 0.3-1MPa respectively). Opening of the BBB was observed in contrast-enhanced images in a 4.7T MRI, through blue dye extravasation and with confocal microscopy. Adverse effects were analyzed on histology. A significant BBB opening limited spatially to the extent of the ultrasound field was observed. BBB opening appeared during the sonication and lasted for several hours. Monitoring was possible on MRI sequences as a significant gadolinium contrast enhancement (p<0.0001). BBB opening was associated with perivascular blood red cell extravasation and transient vascular spasm. In conclusion, the BBB can be opened in large areas of the brain with low power unfocused ultrasound, with limited tissue damage, and could permit safe drug delivery in the brain. Work supported by CarThera and Région Ile-de-France

In Vivo Detection of Succinate by Magnetic Resonance Spectroscopy as a Hallmark of SDHx Mutations in Paraganglioma

International audiencePurpose: Germline mutations in genes encoding mitochon-drial succinate dehydrogenase (SDH) are found in patients with paragangliomas, pheochromocytomas, gastrointestinal stromal tumors, and renal cancers. SDH inactivation leads to a massive accumulation of succinate, acting as an oncometabolite and which levels, assessed on surgically resected tissue are a highly specific biomarker of SDHx-mutated tumors. The aim of this study was to address the feasibility of detecting succinate in vivo by magnetic resonance spectroscopy. Experimental Design: A pulsed proton magnetic resonance spectroscopy (1 H-MRS) sequence was developed, optimized, and applied to image nude mice grafted with Sdhb À/À or wild-type chromaffin cells. The method was then applied to patients with paraganglioma carrying (n ¼ 5) or not (n ¼ 4) an SDHx gene mutation. Following surgery, succinate was measured using gas chromatography/mass spectrometry, and SDH protein expression was assessed by immunohistochemistry in resected tumors. Results: A succinate peak was observed at 2.44 ppm by 1 H-MRS in all Sdhb À/À-derived tumors in mice and in all paragangliomas of patients carrying an SDHx gene mutation, but neither in wild-type mouse tumors nor in patients exempt of SDHx mutation. In one patient, 1 H-MRS results led to the identification of an unsus-pected SDHA gene mutation. In another case, it helped define the pathogenicity of a variant of unknown significance in the SDHB gene. Conclusions: Detection of succinate by 1 H-MRS is a highly specific and sensitive hallmark of SDHx mutations. This non-invasive approach is a simple and robust method allowing in vivo detection of the major biomarker of SDHx-mutated tumors. Clin Cancer Res; 22(5); 1120–9. Ó2015 AACR

Développement de méthodes de spectroscopie RMN localisée 1D filtrée (exposant 1) H (-exposant 13) C double voxel (Application à l exploration d une pathologie cérébrale focale chez le petit animal)

Nous avons développé une méthode de Spectroscopie de Résonance Magnétique pour l exploration dynamique du métabolisme cérébral chez le rat lors de lésions focales, basée sur le suivi de métabolites marqués carbone 13. Dans ce but, nous avons développé et mis au point des séquences de SRM à une dimension (1D) localisée filtrées 1H(-13C) combinées au codage d Hadamard. Ces séquences ont été testées avec les différents systèmes de bobines 1H/13C que nous avons construits. L exploration des atteintes cérébrales focales résultant, chez le rat, de l administration intracérébrale d un agent excitotoxique, l acide quinolinique, a été utilisée pour tester l'efficacité du couple optimal de séquence système de bobines. Cette étude spectroscopique a été associée à une étude par Imagerie de Résonance Magnétique pondérée en diffusion et pondérée en T2 afin de suivre l évolution du volume de la zone lésée dans le même modèle expérimental.We developed a Magnetic Resonance Spectroscopy method for local dynamic investigations of the rat brain metabolism, based on the monitoring of carbon 13 labelled metabolites. For such investigations, we developed and optimized one dimension (1D) localized MRS 1H(-13C) filtered sequences combined with Hadamard encoding. The efficiency of the sequences was tested with the different system of 1H/13C coils we built. The best association of coil device and sequence was applied to the investigation of a focal cerebral injury resulting of the intracerebral administration of an excitotoxic compound, the quinolinic acid. This spectroscopic study was associated to diffusion and T2 weighted imaging studying in order to monitor the evolution of the volume of the injured area in the sameEVRY-BU (912282101) / SudocSudocFranceF

Design, Properties, and In Vivo Behavior of Super­paramagnetic Persistent Luminescence Nanohybrids

International audienc

Spatially broad opening of the blood-brain barrier with an unfocused ultrasound transducer in rabbits

International audienceThe aim of this work was to study the opening of the blood-brain barrier (BBB) over a large volume using an unfocused ultrasound device in the presence of ultrasound contrast agents in rabbits. A mono-element planar 1MHz ultrasound transducer was used to perform burst sonications in 24 healthy New-Zealand white rabbits after craniectomy and during intravenous injection of Sonovue®. The transducer was operated with a pulse repetition frequency of 1Hz, and a range of pulses lengths and in situ acoustic pressures (10-35ms and 0.3-1MPa respectively). Opening of the BBB was observed in contrast-enhanced images in a 4.7T MRI, through blue dye extravasation and with confocal microscopy. Adverse effects were analyzed on histology. A significant BBB opening limited spatially to the extent of the ultrasound field was observed. BBB opening appeared during the sonication and lasted for several hours. Monitoring was possible on MRI sequences as a significant gadolinium contrast enhancement (p<0.0001). BBB opening was associated with perivascular blood red cell extravasation and transient vascular spasm. In conclusion, the BBB can be opened in large areas of the brain with low power unfocused ultrasound, with limited tissue damage, and could permit safe drug delivery in the brain. Work supported by CarThera and Région Ile-de-France

Multifunctional rare-Earth vanadate nanoparticles: luminescent labels, oxidant sensors, and MRI contrast agents.

International audienceCollecting information on multiple pathophysiological parameters is essential for understanding complex pathologies, especially given the large interindividual variability. We report here multifunctional nanoparticles which are luminescent probes, oxidant sensors, and contrast agents in magnetic resonance imaging (MRI). Eu(3+) ions in an yttrium vanadate matrix have been demonstrated to emit strong, nonblinking, and stable luminescence. Time- and space-resolved optical oxidant detection is feasible after reversible photoreduction of Eu(3+) to Eu(2+) and reoxidation by oxidants, such as H2O2, leading to a modulation of the luminescence emission. The incorporation of paramagnetic Gd(3+) confers in addition proton relaxation enhancing properties to the system. We synthesized and characterized nanoparticles of either 5 or 30 nm diameter with compositions of GdVO4 and Gd0.6Eu0.4VO4. These particles retain the luminescence and oxidant detection properties of YVO4:Eu. Moreover, the proton relaxivity of GdVO4 and Gd0.6Eu0.4VO4 nanoparticles of 5 nm diameter is higher than that of the commercial Gd(3+) chelate compound Dotarem at 20 MHz. Nuclear magnetic resonance dispersion spectroscopy showed a relaxivity increase above 10 MHz. Complexometric titration indicated that rare-earth leaching is negligible. The 5 nm nanoparticles injected in mice were observed with MRI to concentrate in the liver and the bladder after 30 min. Thus, these multifunctional rare-earth vanadate nanoparticles pave the way for simultaneous optical and magnetic resonance detection, in particular, for in vivo localization evolution and reactive oxygen species detection in a broad range of physiological and pathophysiological conditions

Preclinical evaluation of targeted therapies in Sdhb-mutated tumors

International audienceTherapies for metastatic SDHB-dependent pheochromocytoma and paraganglioma (PPGL) are limited and poorly efficient. New targeted therapies and identification of early non-invasive biomarkers of response are thus urgently needed for these patients. We characterized an in vivo allograft model of spontaneously immortalized murine chromaffin cells (imCC) with inactivation of the Sdhb gene by dynamic contrast-enhanced MRI (DCE-MRI) and 18FDG-PET. We evaluated the response to several therapies: IACS-010759 (mitochondrial respiratory chain complex I inhibitor), sunitinib (tyrosine kinase inhibitor with anti-angiogenic activity), talazoparib (poly ADP ribose polymerase (PARP) inhibitor) combined or not to temozolomide (alkylating agent), pharmacological inhibitors of HIF2a (PT2385 and PT2977 (belzutifan)) and molecular inactivation of HIF2a (imCC Sdhb-/- shHIF2a). Multimodal imaging was performed, including magnetic resonance spectroscopy (1H-MRS) to monitor the level of succinate in vivo. The allografted model of Sdhb-/- imCC reflected SDHB-deficient tumors, with increased angiogenesis and a particular avidity for 18FDG. After 14 days of treatment, IACS-010759, sunitinib and talazoparib at high doses allowed a significant reduction of the tumor volumes. In contrast to the tumor growth inhibition observed in Sdhb-/- shHIF2a imCC tumors, pharmacological inhibitors of HIF2a (PT2385 and belzutifan) showed no antitumor action in this model, alone or in combination with sunitinib. 1H-MRS, but not DCE-MRI, enabled the monitoring response to sunitinib, which was the best treatment in this study, promoting a decrease in succinate levels detected in vivo. This study paves the way for new therapeutic options and reveals a potential new early biomarker of response to treatment in SDHB-dependent PPGL