Promote Organization and Integration of Regenerated Neurons from Transplanted Human Neural Stem Cells

项目摘要 该项目的总体目标是开发一种纳米纤维-水凝胶复合材料， 来自移植的人多能干细胞（hiPSC）衍生的神经/祖干细胞的分化细胞 神经干细胞（NSC）在脑损伤后的损伤部位，并增强再生神经元的整合 宿主组织越来越多的证据表明，外源性干细胞移植是一种 有希望的策略，以促进受伤的脑组织再生。然而，持续的炎症在 损伤部位和创伤性损伤腔内缺乏支持性组织结构和血管系统 不利的环境导致低细胞存活和对细胞的分化和移植的不良控制， 干细胞移植我们最近表明，优化的透明质酸（HA）水凝胶结合 层粘连蛋白衍生肽作为细胞递送基质，具有结合和富集内源性 血管生成因子，如血管内皮生长因子，产生了强大的新生血管网络内， 水凝胶在创伤性损伤腔中。在该HA水凝胶中递送的人胎儿组织来源的NSC 已经显示出在病变部位植入后的存活率提高，并且大多数存活的NSC 分化成神经元祖细胞并填充整个病变腔。然而，这些神经元 祖细胞在损伤部位表现出紊乱的结构，与宿主皮层组织的整合有限。 由于有序和分层的结构对大脑皮层的功能很重要，对细胞的控制 组织和整合后的NSC移植和分化在病变部位是至关重要的， 基于干细胞的脑损伤治疗取得成功。在这里，我们假设，分化的细胞从 移植的hiPSC衍生的NSC可以通过三维立体定向引导形成排列有序的结构， 在脑损伤部位的水凝胶复合物，这反过来又促进了再生神经元与 宿主组织为了验证这一假设，我们将首先开发一种纳米纤维-水凝胶复合材料， 纳米纤维，并证明其在分化和成熟过程中组织NSC的能力。这是... 水凝胶复合材料将被定制成具有粘合剂线索、优化孔径和模量，以支持人体 iPSC衍生的NSC在指导其迁移和促进其分化和成熟中的作用（目的1）。我们 然后将移植优化的复合支架，以证明我们的方法在 促进脑组织的结构修复，并确保神经功能的改善 (Aim 2）。这种具有确定组成的复合材料对于临床转化是非常理想的。

PROJECT SUMMARY The overall objective of this project is to develop a nanofiber-hydrogel composite that is capable of organizing differentiated cells from the transplanted human pluripotent stem cell (hiPSC)-derived neural/progenitor stem cells (NSCs) at the lesion site following brain injury, and enhancing the integration of the regenerated neurons with host tissue. A growing body of evidences has suggested exogenous stem cell transplantation is one promising strategy to promote injured brain tissue regeneration. However, the ongoing inflammation at the lesion site and the lack of supportive tissue structure and vasculature within the traumatic lesion cavity present a hostile environment that result in low cell survival and poor control over differentiation and engraftment of the transplanted stem cells. We have recently shown that an optimized hyaluronic acid (HA) hydrogel conjugated with laminin-derived peptide as a cell-delivery matrix with the ability to bind and enrich the endogenous angiogenic factors, such as vascular endothelial growth factor, generated a robust neovascular network within the hydrogel at the traumatic lesion cavity. Human fetal tissue-derived NSCs delivered in this HA hydrogel have shown enhanced survival following implantation at the lesion site, and the majority of survived NSCs has differentiated into neuronal progenitors and populated the entire lesion cavity. However, these neuronal progenitors exhibited disorganized structure at the lesion site with limited integration with host cortex tissue. Since an ordered and layered structure is important to the function of the brain cortex, control over cell organization and integration following NSC transplantation and differentiation at the lesion site is critical to the success of stem cell-based therapy for brain injury. Here we hypothesize that the differentiated cells from transplanted hiPSC-derived NSCs can be guided to form aligned and organized structure by a 3D nanofiber- hydrogel composite in brain lesion site, which in turn facilitates the integration of the regenerated neurons with host tissue. To test this hypothesis, we will first develop a nanofiber-hydrogel composite with aligned nanofibers and demonstrate its ability to organize NSCs during differentiation and maturation. The nanofiber- hydrogel composite will be tailored with adhesive cues, optimized pore size and modulus to support human iPSC-derived NSCs in directing their migration and promoting their differentiation and maturation (Aim 1). We will then transplant the optimized composite scaffold to demonstrate the advantages of our approach in promoting structural repair of the brain tissue and ensuing functional improvement in neurological outcomes (Aim 2). This composite with defined compositions is highly desirable for clinical translation.