Nuclear spin polarization can be significantly increased through the process of hyperpolarization, leading to an increase in the sensitivity of nuclear magnetic resonance (NMR) experiments by 4–8 orders of magnitude. Hyperpolarized gases, unlike liquids and solids, can be more readily separated and purified from the compounds used to mediate the hyperpolarization processes. These pure hyperpolarized gases enabled many novel MRI applications including the visualization of void spaces, imaging of lung function, and remote detection. Additionally, hyperpolarized gases can be dissolved in liquids and can be used as sensitive molecular probes and reporters. This mini-review covers the fundamentals of the preparation of hyperpolarized gases and focuses on selected applications of interest to biomedicine and materials science.

Nicotinamide (a vitamin B3 amide) is one of the key vitamins as well as a drug for treatment of M. tuberculosis, HIV, cancer, and other diseases. Here, an improved Zincke reaction methodology is presented allowing for straightforward and scalable synthesis of nicotinamide-1-15N with an excellent isotopic purity (98%) and good yield (55%). 15N nuclear spin label in nicotinamide-1-15N can be NMR hyperpolarized in seconds using parahydrogen gas. NMR hyperpolarization using the process of temporary conjugation between parahydrogen and to-be-hyperpolarized biomolecule on hexacoordinate iridium complex via the Signal Amplification By Reversible Exchange (SABRE) method significantly increases detection sensitivity (e.g., >20 000-fold for nicotinamide-1-15N at 9.4 T) as has been shown by Theis T. et al. (J. Am. Chem. Soc.2015, 137, 1404), and hyperpolarized in this fashion, nicotinamide-1-15N can be potentially used to probe metabolic processes in vivo in future studies. Moreover, the presented synthetic methodology utilizes mild reaction conditions, and therefore can also be potentially applied to synthesis of a wide range of 15N-enriched N-heterocycles that can be used as hyperpolarized contrast agents for future in vivo molecular imaging studies.

Nuclear spin polarization can be significantly increased through the process of hyperpolarization, leading to an increase in the sensitivity of nuclear magnetic resonance (NMR) experiments by 4-8 orders of magnitude. Hyperpolarized gases, unlike liquids and solids, can be more readily separated and purified from the compounds used to mediate the hyperpolarization processes. These pure hyperpolarized gases enabled many novel MRI applications including the visualization of void spaces, imaging of lung function, and remote detection. Additionally, hyperpolarized gases can be dissolved in liquids and can be used as sensitive molecular probes and reporters. This mini-review covers the fundamentals of the preparation of hyperpolarized gases and focuses on selected applications of interest to biomedicine and materials science.

Sustainable agriculture calls for minimal use of agrochemicals in order to protect the environment. It has caused an increase in the rate of nanoparticles use, in particular silver nanoparticles (AgNPs) due to their safety for mammals, unique biological activity and a broad spectrum of action against fungal and bacterial pathogens. Until now the use of AgNPs dispersions in the agricultural sector has been essentially limited due to many factors decreased their stability (mixing with other pesticides, presence of electrolytes). We present a versatile synthesis of polyampholyte surfactant (tallow amphopolycarboxyglycinate) stabilized AgNPs. We took a close look at unique aggregation behavior (via dynamic light scattering and UV-vis spectroscopy) and biocidal activity of obtained silver colloids. AgNPs are characterized by exclusively high aggregative stability in the presence of coagulating agents NaNO 3 and NaSO 4 (up to 1 M), during drying/redispergation, and frost/defrost cycles. The dispersion of AgNPs shows high biocidal activity (EC 50 is ten times lower than commercial species ones) with respect to Phytophthora infestans and phytopathogenic fungi. This points to the possibility of successful application of silver preparations within agriculture with the goal of partial reduction of the use of toxic and expensive synthetic antibiotics and pesticides.

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