MSC Encapsulation with Thin Gel Coating

间充质干细胞（MSC）疗法目前在许多疾病的广泛临床试验中， 但迄今为止的试验的共同主题是移植后MSC的大量损失。这一结果 可能与用于递送的方法有关-临床试验通常利用静脉内（iv）输注 悬浮细胞相比之下，已经在临床前研究中广泛探索了细胞在各种材料中的包封。 研究，以提高移植细胞的存活，但由此产生的颗粒和设备已经太大， 允许IV输注，这给它们的临床应用提供了显著的实际障碍。此外，作为 MSC的生物活性现在被广泛归因于旁分泌，控制细胞的分泌组 在移植后可能对他们的临床成功至关重要。我们最近开发了一种高效的 微流控过程将单细胞封装在非常薄的水凝胶层（约5微米）中;这种薄涂层 仍然允许静脉输注细胞，但大大增加了它们的存活率和持续时间。 血液中的分泌物我们假设这项技术将提供一个及时的新工具， MSC疗法，并显着扩大其临床效用。在此，我们建议进一步发展这一新的 技术，并研究其在造血干细胞治疗（HSCT）背景下的效用。我们已经把 一个独特的团队来解决这个项目的假设，与微流体技术的领导者 （Weitz）、生物材料（Mooney）和造血干细胞（HSC）生物学和HSCT（Scadden）。我们将 通过以下方式实现我们的目标：（1）调整微凝胶的化学和物理性质，并按比例放大 微流控技术，使临床相关数量的MSC能够高效地被封装， (2)确定移植后MSC的持久性和旁分泌如何调节， 定性和定量地，通过包封藻酸盐水凝胶的化学和物理性质， （3）研究微囊化MSCs静脉输注后对移植物治疗的影响 在啮齿类动物模型中HSCT后抗宿主病（GVHD）。在完成这些研究后，我们将 已经验证了这种方法对MSC治疗的有效性和实用性。重要的是， 这些研究将有助于确定MSC分泌组如何影响MSC在GVHD中的有效性， MSC移植后免疫保护的重要性。此外，这种方法也可能 对于MSC的广泛的其他临床应用和许多其他类型的细胞的使用是广泛有用的。 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.