Significance Hyperpolarization is a significant development in MRI because it allows for imaging different metabolites real time vivo. There are no fundamental obstacles to rapid translation of this technique. Yet, date, has been necessary use persistent radicals that need be filtered out before injection and require pharmacological tests, which slow down the overall protocol, leading reduced sensitivity. The demonstration possible prepare purely endogenous agents probe metabolism vivo...

Abstract Hyperpolarization via dynamic nuclear polarization (DNP) is pivotal for boosting magnetic resonance imaging (MRI) sensitivity and dissolution DNP can be used to perform in vivo real-time 13 C MRI. The type of applications however limited by the relatively fast decay time hyperpolarized spin state together with constraint having polarize spins a dedicated apparatus nearby but separated from MRI magnet. We herein demonstrate that polarizing photo-induced radicals, which subsequently...

The most versatile method to increase liquid-state 13C NMR sensitivity is dissolution dynamic nuclear polarization. use of trityl radicals usually required obtain very large polarization via this technique. We herein demonstrate that up 35% can be obtained in about 1.5 h using ubiquitous nitroxyl 13C-labeled sodium salts by partially deuterating the solvents and a polarizer operating at 1 K 7 T.

Abstract In recent years, hyperpolarization of water protons via dissolution Dynamic Nuclear Polarization (dDNP) has attracted increasing interest in the magnetic resonance community. Hyperpolarized may provide an alternative to Gd-based contrast agents for angiographic and perfusion Magnetic Resonance Imaging (MRI) examinations, it report on chemical biochemical reactions proton exchange while perfoming (NMR) investigations. However, hyperpolarizing is challenging. The main reason presence...

Free radicals generated by UV-light irradiation of a frozen solution containing fraction pyruvic acid (PA) have demonstrated their dissolution dynamic nuclear polarization (dDNP) potential, providing up to 30 % [1-

Hyperpolarization via dissolution dynamic nuclear polarization (dDNP) is crucial to significantly increasing the magnetic resonance imaging (MRI) sensitivity, opening up in vivo real-time MRI using 13C-labeled substrates. The range of applications, however, limited by relatively fast decay spin together with constraint having polarize spins near magnet. As recently demonstrated, employment UV-induced nonpersistent radicals represents an elegant solution tackling these drawbacks....

We show that the trityl electron spin resonance (ESR) features, crucial for an efficient dynamic nuclear polarization (DNP) process, are sample-composition-dependent. Working at 6.7 T and 1.1 K with a generally applicable DNP sample solvent mixture such as water/glycerol plus trityl, addition of Gd3+ leads to dramatic increase in [U-13C] glucose from 37 ± 4% 69 3%. This is highest value reported date comparable what can be achieved on pyruvic acid. Moreover, performing ESR measurements under...

Hyperpolarization via dissolution dynamic nuclear polarization (DNP) is a versatile method to dramatically enhance the liquid-state NMR signal of X-nuclei and can be used for performing metabolic molecular imaging. It was recently demonstrated that instead incorporating persistent radicals as source unpaired electron spins, required DNP, nonpersistent photoinduced in frozen beads neat pyruvic acid (PA), most common substrate In present work, it shown same created solutions containing...

Abstract Magnetic Resonance Imaging combined with hyperpolarized 13 C-labelled metabolic contrast agents produced via dissolution Dynamic Nuclear Polarization can, non-invasively and in real-time, report on tissue specific aberrant metabolism. However, hyperpolarization equipment is expensive, technically demanding needs to be installed on-site for the end-user. In this work, we provide a robust methodology that allows remote production of agents. The methodology, built photo-induced...

In addition to the dedicated spin exchange optical pumping (SEOP) technique, an alternative method produce hyperpolarized xenon gas using dynamic nuclear polarization (DNP) followed by a sublimation procedure was proposed. The challenge associated with DNP is obtain solid-state samples required homogeneity following incorporation of into glass-forming solvent. We show that maximum achievable 129Xe strongly depends on concentration dissolved in solvent and properties itself. Using 5 T...

Whether for 13C magnetic resonance studies in chemistry, biochemistry, or biomedicine, hyperpolarization methods based on dynamic nuclear polarization (DNP) have become ubiquitous. DNP requires a source of unpaired electrons, which are commonly added to the sample be hyperpolarized form stable free radicals. Once polarized, presence these radicals is unwanted. These can replaced by nonpersistent created photoirradiation pyruvic acid (PA), annihilated upon dissolution thermalization solid...

Purpose To probe the cardiac metabolism of carbohydrates and short chain fatty acids simultaneously in vivo following injection a hyperpolarized 13 C‐labeled substrate mixture prepared using photo‐induced nonpersistent radicals. Methods Droplets mixed [1‐ C]pyruvic C]butyric were frozen into glassy beads liquid nitrogen. Ethanol addition was investigated as means to increase polarization level. The irradiated with ultraviolet light radical concentration measured by ESR spectroscopy....

Abstract As of today, dissolution Dynamic Nuclear Polarization (dDNP) is the only clinically available hyperpolarization technique for 13 C-MRI. Despite clear path towards personalized medicine that dDNP paving as an alternative and/or complement to Positron Emission Tomography (PET), struggles enter everyday clinical practice. Because minute-long lifetime after dissolution, one reasons lies in need and consequent complexities having machine generates (i.e. polarizer) on site. Since some...

Glucose is the primary fuel for brain; its metabolism linked with cerebral function. Different magnetic resonance spectroscopy (MRS) techniques are available to assess glucose metabolism, providing complementary information. Our first aim was investigate difference between hyperpolarized 13C-glucose MRS and non-hyperpolarized 2H-glucose interrogate glycolysis. Isoflurane anesthesia commonly employed in preclinical MRS, but it affects hemodynamics functional connectivity. A combination of low...

Hyperpolarised (HP) 13 C NMR allows enzymatic activity to be probed in real time live biological systems. The use of vitro models gives excellent control the cellular environment, crucial understanding enzyme kinetics. increased conversion pyruvate lactate cancer cells has been well studied with HP NMR. Unfortunately, equally important metabolic step transport out cell remains undetected, because intracellular and extracellular are measured as a single resonance. Furthermore, typical...

SA-BDPA is a water-soluble, narrow-line width radical previously used for dynamic nuclear polarization (DNP) signal enhancement in solid-state magic angle spinning NMR spectroscopy. Here, we report the first study using under dissolution DNP conditions (6.7 T and 1.15 K). Longitudinal-detected (LOD)-electron spin resonance (ESR) 13C measurements were performed on samples containing 8.4 M [13C]urea dissolved 50:50 water:glycerol (v/v) doped with either 60 or 120 mM SA-BDPA. Two distinct...

Low throughput is one of dissolution Dynamic Nuclear Polarization (dDNP) main shortcomings. Especially for clinical and preclinical applications, where direct 13C nuclei polarization usually pursued, it takes hours to generate single hyperpolarized (HP) sample. Being able hyperpolarize more samples at once represents a clear advantage can expand the range complexity applications. In this work, we present design performance highly versatile customizable dDNP cryogenic probe, herein adapted 5...

Noninvasive tracking of biochemical processes in the body is paramount diagnostic medicine. Among leading techniques spectroscopic magnetic resonance imaging (MRI), which tracks metabolites with an amplified (hyperpolarized) magnetization signal injected into subject just before scanning. Traditionally, brief enhanced period these agents limited clinical imaging. We propose a solution based on amalgamating two materials—one having diagnostic-metabolic activity and other characterized by...

We report a broadband 1H NMR study of the spin dynamics coated maghemite and gold–maghemite hybrid nanostructures with two different geometries, namely dimers core–shells. All samples have superparamagnetic behavior, displaying blocking temperature (TB ∼ 80 K (maghemite), ∼105 (dimer), ∼150 (core–shell)), magnetization reversal time follows Vogel–Fulcher law. observed three anomalies in T1–1 versus T that decrease amplitude when increasing applied magnetic field. suggest are related to...

Dissolution Dynamic Nuclear Polarization (dDNP) was invented almost twenty years ago. Ever since, hardware advancement has observed 2 trends: the quest for DNP at higher field and, more recently, development of cryogen free polarizers. Despite community is slowly migrating towards "dry" systems, many "wet" polarizers are still in use. Traditional can use up to 100 L liquid helium per week, but less sensitive air contamination and have cooling power. These two characteristics make them very...

It was demonstrated that nonpersistent radicals can be generated in frozen solutions of metabolites such as pyruvate by irradiation with ultraviolet (UV) light, enabling radical-free dissolution DNP. Although is endogenous, an excess additional may perturb metabolic processes, making it potentially unsuitable a polarizing agent when studying fatty acids or carbohydrate metabolism. Therefore, the aim study to characterize containing endogenously-occurring alternatives UV-induced radical...

Enhancing the sensitivity of magnetic resonance spectroscopy/imaging (MRS/MRI) by dissolution dynamic nuclear polarization (dDNP) has expanded scope MRS applications to new fields research. Most importantly, it paved way toward noninvasive studies fate a metabolite in real time. As its name implies, typical dDNP experiment, hyperpolarized (HP) sample is extracted from polarizer liquid state. This procedure limits HP signal exploitation time window approximately 1 min, but also only preserve...