The Magnetic Appeal of Silencing Theranostics

Abstract

Islet cell transplantation has recently emerged as a promising means to treat patients with type 1 diabetes. Despite significant success with the Edmonton protocol for intraportal naked islet transplantation (1), there is an active debate regarding whether or not the overall clinical success rates have met initial expectations (2,3). The next vital steps for improving islet cell transplantation protocols include developing a nontoxic and effective means to prevent graft rejection and islet cell death, as well as suitable imaging techniques to noninvasively probe islet engraftment and long-term survival. Although it is currently unknown how long and what percentage of grafted cells survive, estimates suggest that up to only 30% of the initial β-cell mass remains after 2 weeks (4). It is believed that, aside from immunorejection, rapid islet cell death may occur from lack of oxygen before and after transplantation. One way to increase islet cell survival is to store them in perfluorocarbon emulsions that can act as an oxygen sink, leading to improved oxygenation (5). Another approach is to prevent immunorejection by encapsulating islets in semipermeable alginate capsules (6) or a combination of the two approaches (7). Although monitoring of islet engraftment following intraportal injection is possible by prelabeling naked cells (8,9 …