Science to practice: are theranostic agents with encapsulated cells the key for diabetes therapy?

The transplantation of beta cells could be an effective therapy for diabetes, with much better stabilization of blood glucose levels than can be achieved with insulin injection. However, the therapeutic effect of these cell transplants usually lasts for a relatively short time owing to the strong immunologic reactions against the transplants. Protection from the immune system may be achieved by encapsulating the beta cells in such a way that their ability to release insulin is preserved. In the article of Arifi n and colleagues (1), encapsulated beta cells coembedded with DTDTPA (dithiolated diethylenetriaminepentaacetic acid) gadolinium– coated gold nanoparticles are suggested as a biohybrid theranostic transplant. The in vitro and in vivo data presented in the article give hope that these transplants have the potential to solve many of the problems associated with beta cell treatment of diabetes. In this context, the visibility of the transplanted cells at computed tomography (CT), magnetic resonance (MR) imaging, and ultrasonography (US) might give the physician additional fl exibility in monitoring the transplantation procedure and its effectiveness over time. Furthermore, other cellular therapies may benefi t from cellular encapsulation. The combination of imaging of the biohybrid transplants and noninvasive functional assessment is likely to further improve assessment of the viability and function of the transplanted cells.