Hyperpolarized 13C 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 C-13 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-C-13] pyruvate and subsequent C-13 spectroscopy at 11.7 T. H-1 and two-dimensional H-1-(1)Htotal correlation spectroscopy spectra were acquired from extracts of cells grown in uniformly labeled C-13-glucose, on a 16.4 T, to determine C-13 fractional enrichment and distribution of C-13 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 C-13 label from uniformly labeled C-13- 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 63:322-329, 2010. (C) 2010 Wiley-Liss, Inc.