A study of model beta-cells in Diabetes Treatment

描述（由申请人提供）：评估组织工程构建体治疗效果的主要标准是宿主生理功能的成功恢复。由于以下原因，结构的直接和非侵入性体内监测非常重要：它提供了结构功能和体内植入后生理效应之间的相关性;并且它提供了评估结构功能变化的可能性，该结构功能变化可用于在终点效应之前开发结构失效的早期标记。该研究的总体目标是开发一种非侵入性的方法来监测体内植入的组织工程胰腺替代物的功能。NMR是唯一适合进行此类研究的方法，因为它是一种非侵入性方式，能够探测构建体的细胞内代谢，并观察植入部位的宿主解剖结构。NMR光谱和成像技术可以监测几种细胞内和细胞外代谢物，而无需引入外源因子或固定细胞。我们的假设是，NMR可检测的代谢指标可用于监测植入的组织工程胰腺替代物的功能，并提供植入失败的早期指标，而受体仍然血糖正常。在本研究中检查的NMR核包括1H、19 F和31 P，而所用的模型胰腺构建体由包封在藻酸盐/聚-L-赖氨酸/藻酸盐珠中的小鼠胰岛素瘤#TC-tet细胞或小鼠胰岛组成，并包含在允许容易检索的琼脂糖基质中。以下具体目标旨在解决我们的假设：具体目标1：优化电感耦合RF线圈的体内NMR信号采集。具体目标2：开发并验证构建体内时间依赖性氧和细胞密度梯度的模型。具体目标3：非侵入性评估植入的组织工程胰腺替代物的功能，并将其与终点生理事件相关联。我们认为这是一项全面、定量和重要的研究，用于监测植入的组织工程替代物的功能，将在其最终生理效应之前识别与失败相关的代谢事件。建议的实验是建立在强大的初步数据，我们有信心，他们将铺平道路，在组织工程的进一步成像研究。

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.