A study of model beta-cells in Diabetes Treatment

描述(申请人提供)：评估组织工程构建的治疗效果的主要标准是宿主生理的成功恢复。直接和非侵入性的体内监测具有重要的意义，原因如下：它提供了体内植入后构建功能和生理效应之间的相关性；它提供了评估构建功能变化的可能性，可以用于在终点效应之前开发构建失败的早期标记。这项拟议研究的总体目标是开发一种非侵入性方法学，在体内监测植入的组织工程化胰腺替代物的功能。核磁共振特别适合进行这样的研究，因为它是一种非侵入性的手段，能够探测构建物的细胞内代谢，并观察植入部位宿主的解剖结构。核磁共振波谱和成像技术可以监测几种细胞内和细胞外的代谢物，而不需要引入外来试剂或固定细胞。我们的假设是，核磁共振可检测到的代谢指标可以用来监测植入的组织工程化胰腺替代品的功能，并在受体仍处于正常血糖的情况下提供植入失败的早期指标。本研究中检测的核磁共振核包括1H、19F和31P，而所使用的模型胰腺结构由小鼠胰岛素瘤#TC-TET细胞或包裹在海藻酸盐/多L赖氨酸/海藻酸盐微珠中的小鼠胰岛组成，并包含在琼脂基质中，便于检索。以下具体目标旨在解决我们的假设：具体目标1：利用电感耦合射频线圈优化体内核磁共振信号采集。具体目标2：开发和验证结构内随时间变化的氧气和细胞密度梯度模型。具体目标3：非侵入性评估植入的组织工程化胰腺替代物的功能，并将其与终点生理事件相关联。我们相信，这是一项全面、定量和重要的研究，旨在监测植入的组织工程化替代物的功能，将在其最终生理效应之前识别与失败相关的代谢事件。拟议的实验是建立在强大的初步数据基础上的，我们相信它们将为组织工程中进一步的成像研究铺平道路。

DESCRIPTION (provided by applicant): The main criterion in assessing the therapeutic efficacy of tissue engineered construct is the successful restoration of the host's physiology. Direct and non-invasive in vivo monitoring of a construct is of great importance for the following reasons: it provides correlations between construct function and physiologic effects post-implantation in vivo; and it offers the possibility of assessing changes in construct function that may be used to develop early markers of construct failure in advance of the end-point effects. The overall objective of the proposed research is to develop a noninvasive methodology to monitor in vivo the function of an implanted tissue engineered pancreatic substitute. NMR is uniquely suited to perform such studies since it is a non-invasive modality that has the ability to probe into the intracellular metabolism of the construct, and to view the anatomy of the host at the site of implantation. NMR spectroscopic and imaging techniques can monitor several intracellular and extracellular metabolites without necessitating the introduction of foreign agents or the fixation of cells. It is our hypothesis that NMR detectable metabolic indexes can be used to monitor the function of an implanted tissue engineered pancreatic substitute and provide early indicators of implant failure while the recipient is still euglycemic. The NMR nuclei examined in this study include 1H, 19F and 31P, while the model pancreatic construct utilized is composed of mouse insulinoma #TC-tet cells or mouse islets encapsulated in alginate/poly-L- lysine/alginate beads and contained within an agarose matrix that allows for easy retrieval. The following Specific Aims are designed to address our hypothesis: Specific Aim 1: To optimize in vivo NMR signal acquisition with inductively coupled RF-coils. Specific Aim 2: To develop and validate a model of time-dependent oxygen and cell density gradients within constructs. Specific Aim 3: To non-invasively assess the function of an implanted tissue engineered pancreatic substitute and correlate that to end point physiologic events. We believe this to be a thorough, quantitative and a significant study to monitor the function of an implanted tissue engineered substitute that will identify metabolic events associated with failure ahead of its end physiologic effect. Proposed experiments are founded on strong preliminary data and we are confident that they will pave the way for further imaging studies in tissue engineering.