Fast sample injection for dissolution dynamic nuclear polarisation NMR spectroscopy

Introduction: One of the most critical problems of NMR is the intrinsic lack of sensitivity owing to the small energy difference between nuclear energy levels. This issue can be addressed in different ways. One possibility is to reduce the spectral noise, which to a large extent is created by the console electronics. Another approach is to actually increase the signal strength of the NMR signal. An experimental approach to achieve this is ex situ dissolution Dynamic Nuclear Polarisation. It increases the population difference of the spin states by transferring the high electron polarization to the NMR detectable nuclei. A theoretical introduction into NMR, quantum mechanical basics of spin physics and DNP are presented in Chapters 1 and 2. Methods: One of the main drawbacks of D-DNP is the necessity for a post-polarisation sample transfer to an NMR spectrometer. One of the major aims of the work presented in this thesis was to build an autonomous robotic device to transfer the sample under pressure controlled by Arduino microelectronics to overcome problems associated with the sample transfer. Chapter 3 presents how this device was constructed and. In addition applications performed using this device are presented. Results: The benefits of the application of this device for fast-relaxing nuclei are discussed in chapter 4 with the application on 2-D DNP-NMR acquisition of U-$^1$$^3$C Glucose. Novel experiments using Dissolution DNP were also performed as part of the work for this thesis. A method for analysing aminoacids of biological fluids using DNP is presented in the Chapter 5 by acetylating which creates long lived tags. An approach for extracting the maximum of information out of a single polarisation experiment is what Chapter 6 covers with an approach to perform Parallel Receiver DNP and the application on ATP and 1-13C TetraMethylPhosphonium. Finally, the future applications of the DNP and the authors’ personal ideas for further development are presented in Chapter 7, the discussion. Briefly, DNP-NMR using a fast sample transfer system can be a capable system for performing different types of analysis, but the maximum outcome is always when the system is combined with $in-vivo$ MRI scanners

Improved stability and spectral quality in ex situ dissolution DNP using an improved transfer device

Dissolution dynamic nuclear polarization (DNP) has become one of the predominant implementations for DNP. However, the technical implementation of transferring the sample from the polarizer to the nuclear magnetic resonance (NMR) system remains challenging. There is a need for additional technical optimizations in order to use dissolution DNP for biochemical and chemical applications. Here we show how a newly designed pressure dissolution kit considerably improves spectral quality and stability by enabling highly reliable and fast sample transfer to the NMR system

Classification and biomarker identification of prostate tissue from TRAMP mice with hyperpolarized 13C-SIRA

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Improved stability and spectral quality in ex situ dissolution DNP using an improved transfer device

Dissolution dynamic nuclear polarization (DNP) has become one of the predominant implementations for DNP. However, the technical implementation of transferring the sample from the polarizer to the nuclear magnetic resonance (NMR) system remains challenging. There is a need for additional technical optimizations in order to use dissolution DNP for biochemical and chemical applications. Here we show how a newly designed pressure dissolution kit considerably improves spectral quality and stability by enabling highly reliable and fast sample transfer to the NMR system

Classification and biomarker identification of prostate tissue from TRAMP mice with hyperpolarized 13C-SIRA

Hyperpolarized 13C isotope resolved spectroscopy boosts NMR signal intensity, which improves signal detection and allows metabolic fluxes to be analyzed. Such hyperpolarized flux data may offer new approaches to tissue classification and biomarker identification that could be translated in vivo. Here we used hyperpolarized stable isotope resolved analysis (SIRA) to measure metabolite specific 13C isotopic enrichments in the central carbon metabolism of mouse prostate. Prostate and tumor tissue samples were acquired from transgenic adenocarcinomas of the mouse prostate (TRAMP) mice. Before euthanasia, mice were injected with [U–13C]glucose intraperitoneally (i.p.). Polar metabolite extracts were prepared, and hyperpolarized 1D-13C NMR spectra were obtained from normal prostate (n = 19) and cancer tissue (n = 19) samples. Binary classification and feature analysis was performed to make a separation model and to investigate differences between samples originating from normal and cancerous prostate tissue, respectively. Hyperpolarized experiments were carried out according to a standardized protocol, which showed a high repeatability (CV = 15%) and an average linewidth in the 1D-13C NMR spectra of 2 ± 0.5 Hz. The resolution of the hyperpolarized 1D-13C spectra was high with little signal overlap in the carbonyl region and metabolite identification was easily accomplished. A discrimination with 95% success rate could be made between samples originating from TRAMP mice prostate and tumor tissue based on isotopomers from uniquely identified metabolites. Hyperpolarized 13C-SIRA allowed detailed metabolic information to be obtained from tissue specimens. The positional information of 13C isotopic enrichments lead to easily interpreted features responsible for high predictive classification of tissue types. This analytical approach has matured, and the robust experimental protocols currently available allow systematic tracking of metabolite flux ex vivo

Classification and biomarker identification of prostate tissue from TRAMP mice with hyperpolarized 13C-SIRA

Hyperpolarized 13C isotope resolved spectroscopy boosts NMR signal intensity, which improves signal detection and allows metabolic fluxes to be analyzed. Such hyperpolarized flux data may offer new approaches to tissue classification and biomarker identification that could be translated in vivo. Here we used hyperpolarized stable isotope resolved analysis (SIRA) to measure metabolite specific 13C isotopic enrichments in the central carbon metabolism of mouse prostate. Prostate and tumor tissue samples were acquired from transgenic adenocarcinomas of the mouse prostate (TRAMP) mice. Before euthanasia, mice were injected with [U–13C]glucose intraperitoneally (i.p.). Polar metabolite extracts were prepared, and hyperpolarized 1D-13C NMR spectra were obtained from normal prostate (n = 19) and cancer tissue (n = 19) samples. Binary classification and feature analysis was performed to make a separation model and to investigate differences between samples originating from normal and cancerous prostate tissue, respectively. Hyperpolarized experiments were carried out according to a standardized protocol, which showed a high repeatability (CV = 15%) and an average linewidth in the 1D-13C NMR spectra of 2 ± 0.5 Hz. The resolution of the hyperpolarized 1D-13C spectra was high with little signal overlap in the carbonyl region and metabolite identification was easily accomplished. A discrimination with 95% success rate could be made between samples originating from TRAMP mice prostate and tumor tissue based on isotopomers from uniquely identified metabolites. Hyperpolarized 13C-SIRA allowed detailed metabolic information to be obtained from tissue specimens. The positional information of 13C isotopic enrichments lead to easily interpreted features responsible for high predictive classification of tissue types. This analytical approach has matured, and the robust experimental protocols currently available allow systematic tracking of metabolite flux ex vivo