| The immunoisolation of pancreatic beta cells, and islet transplantation, have emerged as promising therapies for treating Type I diabetes. Currently, the efficacy of these implants/transplants is assessed via measurement of serum glucose levels, which provides no direct information on the graft functional volume and on the formation of necrotic islet-cells. Also, beta cell insulin production rate may remain constant through hypoxic episodes, while the levels of ATP, glucose consumption, and lactate production may vary significantly. Therefore, being able to directly image cellular function would provide a useful tool in understanding beta cell function.; Glucose stimulated influx of calcium into β-cells via voltage-gated channels is necessary for insulin release. Divalent manganese is a calcium analog and can enter cells through voltage-gated calcium channels. Manganese is a well-known Magnetic Resonance (MR) contrast agent. Here we demonstrate the use of manganese-enhanced MR microimaging to directly image beta cell function and viability using radio frequency microcoils. MR sensitivity enhancement is achieved by matching RF coil dimensions to the sample volume.; In light of clinical needs, it is critical to develop non-invasive techniques that can help study the in vivo implant/transplant efficacy, and periodically assess functional status and viability of the encapsulated cells. Magnetic resonance imaging is a non-invasive modality that provides information on anatomy as well as function. This imaging technique was used to successfully characterize beta cell activation in response to glucose stimulation. This information will help optimize implants/transplants and their performance. |
