STEM CELL TRACKING: IN VITRO AND IN VIVO APPLICATIONS

这个子项目是利用由NIH/NCRR资助的中心拨款提供的资源的许多研究子项目之一。子项目和调查员(PI)可能从另一个NIH来源获得了主要资金，因此可能会出现在其他CRISE条目中。列出的机构是针对中心的，而不一定是针对调查员的机构。追踪标记的干细胞/祖细胞在迁移和种植时的情况，考虑到体内的组织片段。我们的目标是：-帮助确定最好的种植技术(例如，在组织内或通过动脉/静脉注射)，使大多数贴壁干细胞留在受伤的组织部位。-利用PET开发体内干细胞的独特细胞监测能力。在这个过程中，干细胞被预先标记了使用Lenti载体技术的硫胺酸激酶(TK)结构。细胞标记后，固有的TK裂解FHBG PET探针激活PET信号。在这里，体内细胞迁移和聚集的长期研究可以通过允许预先标记的TK干细胞在非特定的时间段内附着在组织成分内，然后在图像采集之前激活PET信号来分析。-使用负对比磁共振成像，我们将同时(与PET一起)监测体内干细胞在组织部位种植的情况。在这种成像方式中，独特的微铁颗粒(包括A)外部葡聚糖涂层或B)特异性受体-配体通讯(例如EpCAM)被用来促进铁颗粒的内吞作用，从而使不同的铁浓度位于细胞质内。该标记过程用于干扰MR信号并促进负信号成像。-量化诱导组织修复所需的细胞量。-可视化最小聚集大小的干细胞信号(希望是单细胞悬浮液)，因为它们将自己种植在受损组织的毛细血管床中。目前，干细胞疗法假定种子细胞留在感兴趣的组织内。事实上，许多细胞流经受损的组织，并将自己植入全身的各种毛细血管床中。改进的贴壁方法对于可视化细胞的分散、可视化细胞聚集的大小以及具体量化残留在组织损伤部位的干细胞数量是必要的。

This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. The subproject and investigator (PI) may have received primary funding from another NIH source, and thus could be represented in other CRISP entries. The institution listed is for the Center, which is not necessarily the institution for the investigator. To track labeled stem/progenitor adherent cells as they migrate and seed thoughout in-vivo tissue segements. The goals are: - To help determine the best seeding techniques (e.g. either within tissues or via arterial/venus injections) that would allow most adherent stem cells to remain at the injured tissue sites. - To develop unique cell monitoring capabilities, using PET, of in-vivo stem cells. In this process stem cells are pre-labeled with a thimadine kinase (TK) constructs using lenti vector technologies. After cell labeling, the inherent TK cleaves an FHBG PET probe to activate PET signaling. Here, long term investiagations of in-vivo cell migration and aggregation may be analyzed by allowing pre-labeled TK stemcells to adhere inside tissue components over nonspecific time fames - then activate PET signaling prior to image acquisition. - Using negative contrast MRI, we will concurrently (along with PET) monitor in-vivo stem cells as they are seeded within tissues sites. For this imaging modality, unique micro iron particles that include either A)outer dextran coatings, or B)specific receptor-ligand communications (e.g. EpCAM), are used to promote endocytosis of iron particles such that distinctive iron concentrations are located within the cells cytoplasm. This labeling proces is used to disrupt MR signaling and promote negative signal imaging. - To quantify the amount of cells needed to induce tissue repair. - To visualize a stem cell signal of the smallest aggregate size (hopefully single cell suspensions) as they seed themselves inside capillary beds of injured tissues. At present, stem cell therapies assume that seeded cells remain within the tissues of interest. In reality, many cells flow through the damaged tissues and implant themselves inside various capillary beds throughout the body. Improved tacking methods are necessary to visualize the dispersion of cells, to visualize cell aggregate sizes, and to specifically quantify stem cell numbers that remain at the tissue injury sites.