Hyperpolarized 13 C spectroscopy and an NMR‐compatible bioreactor system for the investigation of real‐time cellular metabolism

The purpose of this study was to combine a three‐dimensional NMR‐compatible bioreactor with hyperpolarized 13 C NMR spectroscopy in order to probe cellular metabolism in real time. JM1 (immortalized rat hepatoma) cells were cultured in a three‐dimensional NMR‐compatible fluidized bioreactor. 31 P spectra were acquired before and after each injection of hyperpolarized [1‐ 13 C] pyruvate and subsequent 13 C spectroscopy at 11.7 T. 1 H and two‐dimensional 1 H‐ 1 H‐total correlation spectroscopy spectra were acquired from extracts of cells grown in uniformly labeled 13 C‐glucose, on a 16.4 T, to determine 13 C fractional enrichment and distribution of 13 C label. JM1 cells were found to have a high rate of aerobic glycolysis in both two‐dimensional culture and in the bioreactor, with 85% of the 13 C label from uniformly labeled 13 C‐glucose being present as either lactate or alanine after 23 h. Flux measurements of pyruvate through lactate dehydrogenase and alanine aminotransferase in the bioreactor system were 12.18 ± 0.49 nmols/sec/10 8 cells and 2.39 ± 0.30 nmols/sec/10 8 cells, respectively, were reproducible in the same bioreactor, and were not significantly different over the course of 2 days. Although this preliminary study involved immortalized cells, this combination of technologies can be extended to the real‐time metabolic exploration of primary benign and cancerous cells and tissues prior to and after therapy. Magn Reson Med, 2010. © 2010 Wiley‐Liss, Inc.