This thesis presents the development and implementation of magnetic resonance techniques to study biopharmaceutical samples, specifically from upstream bioreactors. The motivation for this research is to improve our ability to produce therapeutic proteins of appropriate quality and quantity. The aim of this research is therefore to explore the extent to which NMR techniques can be used to quantify the ratio of intra and extracellular proteins present in a biopharmaceutical production line; with the purpose of building up a quantitative method which can be used to non-invasively monitor quality. Although NMR techniques exist for the study of macro-proteins and in-cell environments, previous studies have mostly failed to design NMR-tools capable of evaluating these samples in their native form, or transferrable to bench-scale spectrometers for at-line industrial application.
Bovine serum albumin and an IgG1 antibody are used as model extracellular proteins. Due to the difficulties imposed by the large size of the proteins and the intense resonances produced by their media solutions, the experimental techniques require optimization of the NMR pulse parameters and effective solvent suppression. The new pulse sequences T1-WATERGATE, T2-WATERGATE and Diff-WATERGATE are proposed, which allow for the visualization and assessment of macro-protein signals. The effects of protein concentration on diffusion coefficients, relaxation times and spectral peak area are explored. The possibility of developing calibration curves for concentration determination are shown through both the use of 1D 1H WATERGATE spectra and the water-proton transverse relaxation rate (R2(1H2O)), with the latter being transferrable to bench-scale. Chinese hamster ovary cells were used to provide an intracellular environment, which is found to have an associated self-diffusion coefficients 70 times slower than that of extracellular proteins. This work demonstrates how varying the NMR acquisition parameters allows for the self-diffusion coefficients of proteins of different sizes or of different cellular environments to be obtained. Additionally a novel means of monitoring the growth of a mammalian cell line at bench-scale is shown through simple one-shot CPMG experiments. Lastly, this study presents the first use of magnetic resonance imaging (MRI) velocimetry to study the flow field inside an ambr15® microscale bioreactor. MRI provides a non-invasive method for the highly accurate visualisation of these hydrodynamics and a means for validating CFD predictions.