MSC Encapsulation with Thin Gel Coating

间充质干细胞(MSC)疗法目前正在对许多疾病进行广泛的临床测试， 但到目前为止，试验的一个共同主题是移植后MSCs的大量丧失。这个结果 可能与用于分娩的方法有关-临床试验通常使用静脉(IV)输注 悬浮细胞。相比之下，用各种材料包裹细胞在临床前已得到广泛探索。 旨在提高移植细胞存活率的研究，但由此产生的粒子和设备太大，无法 允许静脉输液，为其临床实施提供了重大的实际障碍。此外，作为 目前，间充质干细胞的生物活性被广泛地归因于旁分泌，即控制细胞的分泌体。 移植后的移植可能是他们临床成功的关键。我们最近开发了一种高效的 将单个细胞包裹在一层非常薄的水凝胶(~5微米)中的微流控过程；这种薄涂层 仍然允许细胞通过静脉输注，但显著增加了细胞的存活率和持续时间 它们在血液中的分泌产物。我们假设这项技术将提供一种及时的新工具 MSC疗法，并极大地扩展了它们的临床用途。在这里，我们建议进一步开发这一新的 技术，并研究其在造血干细胞治疗(HSCT)中的应用。我们已经把 一个独特的团队来解决这个项目背后的假设，由微流控技术的领导者组成 (Weitz)、生物材料(Mooney)和造血干细胞(HSC)生物学和HSCT(Scadden)。我们会 追求我们的目标：(1)调整微凝胶的化学和物理性质，并扩大 微流控技术使临床相关数量的MSCs能够高效地被包裹， (2)确定移植后MSC持久性和旁分泌的调节方式，两者 通过对微囊化海藻酸水凝胶的化学性质和物理性质的定性和定量研究， 以及(3)研究凝胶包裹的MSCs在静脉输注后对移植物治疗的影响。 在啮齿动物模型中对HSCT后宿主疾病(GVHD)的影响。在这些研究完成后，我们会 已经验证了这种方法在MSC治疗中的有效性和实用性。重要的是，结果是 这些研究将有助于确定MSC分泌组如何影响MSCs在GVHD中的有效性，以及 骨髓间充质干细胞移植后免疫保护的重要性此外，这种方法还可能 对骨髓间充质干细胞广泛的其他临床应用以及许多其他类型的 干细胞。

Mesenchymal stem cell (MSC) therapies are currently in widespread clinical testing for a number of diseases, but a common theme of trials to date is the massive loss of the MSCs following transplantation. This outcome likely relates to the approach utilized for delivery – clinical trials typically utilize intravenous (iv) infusion of suspended cells. In contrast, encapsulation of cells in various materials has been widely explored in preclinical studies to enhance transplanted cell survival, but the resulting particles and devices have been too large to allow iv infusion, providing a significant practical obstacle to their clinical implementation. Further, as the bioactivity of MSCs is now widely ascribed to paracrine secretions, control over the secretome of the cells following transplantation may be crucial to their clinical success. We recently developed a highly efficient microfluidic process to encapsulate single cells in a very thin layer of hydrogel (~ 5 microns); this thin coating still allows cells to be infused intravenously, but dramatically increases both their survival and the duration of their secreted products in the bloodstream. We hypothesize this technology will provide a timely new tool for MSC therapies and dramatically expand their clinical utility. Here, we propose to further develop this new technology, and to study its utility in context of hematopoietic stem cell therapy (HSCT). We have put together a unique team to address the hypothesis underlying this project, with leaders in microfluidics technology (Weitz), biomaterials (Mooney), and hematopoietic stem cell (HSC) biology and HSCT (Scadden). We will pursue our objectives by: (1) Tune the chemical and physical properties of microgels, and scale-up the microfluidics technology to enable clinically relevant numbers of MSCs to be encapsulated with high efficiency, (2) Determine how MSC persistence and paracrine secretions following transplantation can be tuned, both qualitatively and quantitatively, by the chemical and physical properties of the encapsulating alginate hydrogel, and (3) Study the impact of gel-encapsulated MSCs, following intravenous infusion, on the treatment of graft versus host disease (GVHD) following HSCT in a rodent model. At the completion of these studies we will have validated the effectiveness and practicality of this approach to MSC therapy. Importantly, the results of these studies will help to define how the MSC secretome impacts the effectiveness of MSCs in GVHD, and the importance of immunoprotection of the MSCs following transplantation. Further, this approach is also likely to be broadly useful to the wide array of other clinical applications of MSCs and to the use of many other types of stem cells.