<p>Islet Transplantation Imaging in vivo</p>

Abstract

Although islet transplantation plays an effective and powerful role in the treatment of diabetes, a large amount of islet grafts are lost at an early stage due to instant bloodmediated inflammatory reactions, immune rejection, and β-cell toxicity resulting from immunosuppressive agents. Timely intervention based on the viability and function of the transplanted islets at an early stage is crucial. Various islet transplantation imaging techniques are available for monitoring the conditions of post-transplanted islets. Due to the development of various imaging modalities and the continuous study of contrast agents, noninvasive islet transplantation imaging in vivo has made great progress. The tracing and functional evaluation of transplanted islets in vivo have thus become possible. However, most studies on contrast agent and imaging modalities are limited to animal experiments, and long-term toxicity and stability need further evaluation. Accordingly, the clinical application of the current achievements still requires a large amount of effort. In this review, we discuss the contrast agents for MRI, SPECT/PET, BLI/FI, US, MPI, PAI, and multimodal imaging. We further summarize the advantages and limitations of various molecular imaging methods.

Noninvasive Tracking of mPEG-poly(Ala) Hydrogel-Embedded MIN6 Cells after Subcutaneous Transplantation in Mice

“…To better understand the fate of islets after transplantation, accurate, reproducible, and noninvasive imaging is needed. Such approaches have been investigated by using different imaging modalities, such as positron emission tomography (PET), single-photon emission computed tomography (SPECT), magnetic resonance imaging (MRI), ultrasonography (US), bioluminescence imaging (BLI) fluorescence imaging, magnetic particle imaging (MPI), and photoacoustic imaging (PAI) [ 28 , 29 ]. In this study, we subcutaneously transplanted MIN6 cells embedded in a scaffold with mPEG-poly(Ala) hydrogels and examined these grafts for up to 65 days by using MR and bioluminescence imaging.…”

Mouse models and human islet transplantation sites for intravital imaging

“…Although magnetic resonance imaging (MRI) is an appealing clinically relevant model to image physiological processes in vivo , few MRI studies have been performed on transplanted human islets since the method was first introduced in 2011 ( 99 ). This lack of current research is due to challenges associated with generation of radiolabels, however, with the increased development of targeted nanoparticles in the field ( 100 – 102 ), there is a promising future for this imaging method ( 103 ). Although these discussed imaging studies have made important contributions to the field of diabetes with studies in islet mass following transplantation, these methods of non-invasive imaging lack the ability to acquire high-resolution images, losing the potential to visualize detailed dynamic processes occurring within the islets in real time.…”

Identification and Validation of a New Peptide Targeting Pancreatic Beta Cells

“…The final goal of developing a beta cell-specific molecular probe is to provide a non-invasive, in vivo imaging method for measuring BCM during diabetes progression and tracking islet grafts after islet transplantation, so that necessary and timely intervention can be performed [ 19 ]. Therefore, all presumed beta cell-specific probes screened in vitro have to be validated by in vivo studies.…”