Combined Nanoparticle and Neural Stem Cell Therapies in a Pig Model of Stroke

 描述(申请人提供)：中风是导致美国成年人残疾的首要原因，也是导致死亡的第四大原因。纤溶酶原激活剂仍然是食品和药物管理局(FDA)批准的唯一治疗中风的药物。然而，这种治疗在有效性、安全性和有效窗口方面都有很大的局限性。缺乏任何有效的恢复性药理学方法表明迫切需要基于干细胞的疗法。一类新的自体神经干细胞(NSCs)被称为诱导多能干细胞来源的NSCs(INSCs)，具有向神经元、星形胶质细胞分化的能力 和少突胶质细胞，并整合到受损的脑组织代表着一个令人兴奋的再生治疗群体。然而，由于这些细胞在卒中后高水平的活性氧(ROS)和炎性细胞因子的细胞毒性环境下的生存问题，它们的疗效表现出显著的差异性。这表明，用适当的抗氧化剂和抗炎剂对受损的脑组织进行预处理，将显著提高移植物的存活率，并最终改善组织和功能结果。我们最近开发了一种高度亲脂的可生物降解纳米颗粒(NP)传递平台，能够穿过血脑屏障(BBB)并传递抗氧化剂INSIE，这种线粒体基质富含ROS和抗炎剂，位于扩散炎症的脑白质中。有了这一成功，我们假设，在大型动物模型(如大脑与人类相似的猪)中，开发基于NP递送神经保护剂-干细胞联合疗法的治疗方案可能是非常有益的。为了构建这一NP平台并展示其潜力，我们定义了以下特定目标：(1)构建并体外优化含线粒体抗氧化和抗炎剂的BBB穿透性可生物降解NP；(2)安全性、毒性、在正常仔猪中的分布以及对猪大脑中动脉阻塞(MCAO)缺血性损伤模型的治疗效果；(3)NP-干细胞联合治疗猪MCAO卒中模型。本研究将为卒中后神经保护剂-干细胞联合治疗提供潜在的纳米医学平台。靶向纳米粒组成简单，由具有良好特性的可生物降解的靶向部分添加的聚合物构建，这将非常有利于临床翻译。

 DESCRIPTION (provided by applicant): Stroke is the leading cause of disability and the fourth leading cause of death amongst adults in the United States. Plasminogen activator remains the only food and drug administration (FDA)-approved drug for stroke treatment. However this treatment has significant limitations in efficacy, safety, and the window of effectiveness. The lack of any effective restorative pharmacological approaches indicates the urgent need of stem cell-based therapies. A new class of autologous neural stem cells (NSCs) known as induced pluripotent stem cell derived NSCs (iNSCs) with abilities to differentiate into neurons, astrocytes and oligodendrocytes and to integrate into damaged brain tissue represents an exciting regenerative therapeutic population. However, these cells show significant variability in efficacy due to their survival issues under the cytotoxic environment after stroke with high levels of reactive oxygen species (ROS) and inflammatory cytokines. This suggests that pre-treatment of the damaged brain with anti-oxidant and anti-inflammatory agents appropriately delivered to the target tissue would significantly improve survival of transplants and ultimately tissue and functional outcomes. We recently developed a highly lipophilic biodegradable nanoparticle (NP) delivery platform with ability to cross the blood brain barrier (BBB) and deliver anti-oxidant insie the mitochondrial matrix rich in ROS and anti-inflammatory agent in the white matter of the brain where inflammation is diffused. With this success, we hypothesized that development of therapeutic options based on combined NP delivered neuroprotectant-stem cell therapy after stroke in a large animal model such as pig with brains similar to human can be extremely beneficial. To construct this NP platform and to demonstrate its potential, we have defined the following Specific Aims: (1) Construction and in vitro optimization of a BBB penetrating targeted biodegradable NP containing mitochondria acting anti-oxidant and anti-inflammatory agents; (2) Safety, toxicity, distribution in normal piglet and therapeutic efficacy in a pig middle cerebral artery occlusion (MCAO) ischemic injury model; (3) Combined therapeutic NP-stem cell therapy in a pig MCAO stroke model. This study will provide a potential nanomedicine platform for combined neuroprotectant-stem cell therapy after stroke. The targeted NPs are simple in composition and constructed from a well characterized biodegradable targeting moiety appended polymer which will be extremely beneficial for clinical translation.