Novel Strategy Development for Neuroprotective Therapeutics Delivery in Stroke

描述（由申请人提供）：在缺血性卒中的早期阶段，rt-PA与神经保护剂的联合治疗是一种有前景的治疗策略。有证据表明，氙等生物活性气体具有深刻的神经保护作用，具有易于通过血脑屏障、扩散迅速和无已知副作用的优点。然而，由于缺乏合适的输送方法，这些气体的使用受到限制。我们之前的研究在开发适合生物活性气体包封、rt-PA结合、凝块靶向、血栓溶解和超声控制的生物活性气体释放的脂质体制剂方面取得了许多里程碑。本研究的目的是开发、优化和测试一种新型的多功能回声脂质体（ELIP）制剂，其具有溶栓剂和神经保护性生物活性气体共包封、凝块靶向、超声和凝块溶解调节释放神经保护性气体，用于溶栓相关的神经保护治疗。具体目标是：（1）优化氙和其他神经保护气体到ELIP中的封装，以延长循环时间和充分的生物活性气体释放;（2）评估各种超声参数以触发生物活性气体从所提出的ELIP制剂释放，和（3）优化和鉴定在血栓溶解期间由rt-PA与凝块的相互作用触发的气体和气体/环糊精复合物释放，并且一旦完成目的1，图2和图3，以测试该策略在缺血性中风的体内大鼠模型中恢复脑循环和预防神经元损伤的功效。在缺血性中风动物模型中，将通过颈动脉超声释放生物活性气体静脉内施用含有神经保护气体和rt-PA的多功能ELIP。我们预计，这种策略将提高rt-PA的治疗窗口，防止神经元损伤，从而加强脑保护。所开发的技术将为生物活性气体封装提供独特的多功能载体，这些载体可以容易地施用、位点特异性递送和US/溶栓控制释放。这可能有助于克服目前可用的策略所看到的不完全溶栓和脑缺血损伤的问题。在这项研究中开发的气体封装和输送技术可以转化为实体，其中生物活性气体输送可能是有益的。 公共卫生相关性：本提案的目的是开发和评价一种重组组织纤溶酶原激活剂（rt-PA）包被的回声脂质体制剂，用于超声和溶栓控制的神经保护气体输送至脑循环，用于治疗与血栓性卒中相关的缺血性脑损伤。这可能有助于克服目前可用的策略所看到的不完全溶栓和脑缺血损伤的问题。在这项研究中开发的气体封装和输送技术可以转化为实体，其中生物活性气体输送可能是有益的。

DESCRIPTION (provided by applicant): Combination therapeutic of rt-PA with a neuroprotective agent in the early phase of ischemic stroke is a promising therapeutic strategy. Evidences suggests that bioactive gases such as xenon have profound neuroprotective effects with advantages of ready passage through blood-brain barrier, rapid diffusion and no known side effects. However, use of these gases has been limited by lack of suitable delivery methods. Our previous research has achieved a number of milestones in developing liposomal formulations that are suitable for bioactive gas encapsulation, rt-PA association, clot targeting, thrombolysis and ultrasound-controlled bioactive gas release. The propose of this research is to develop, optimize and test a novel multifunctional echogenic liposomal (ELIP) formulation with thrombolytic agent and neuroprotective bioactive gas co-encapsulation, clot targeting, ultrasound and clot lysis modulated-release of neuroprotective gases for thrombolytic associated neuroprotective therapy. The specific aims are: (1) to optimize the encapsulation of xenon and other neuroprotective gases into ELIP for prolonged circulation time and sufficient bioactive gas release; (2) to evaluate various ultrasound parameters to trigger bioactive gases release from the proposed ELIP formulation, and (3) to optimal and identify gas and gas/cyclodextrin complexes release triggered by the interaction of rt-PA with clot during thrombolysis and once finished aims 1,2 and 3, to test the efficacy of this strategy in restoring cerebral circulation and preventing neuronal damage in an in vivo rat model of ischemic stroke. Multifunctional ELIP containing neuroprotective gases and rt-PA will be administered intravenously with carotid artery ultrasound release bioactive gas in an animal model of ischemia stroke. We anticipate that this strategy will enhance rt-PA therapeutic window and prevent neuronal damage, resulting in strengthened cerebral protection. Techniques developed will provide unique multifunctional vectors for bioactive gas encapsulation that can be easily administered, site-specific delivery and US/thrombolysis-controlled release. This may help overcome problems of incomplete thrombolysis and cerebral ischemia injury seen with current available strategies. Gas encapsulation and delivery technique developed in this research can be translated into entities in which bioactive gas delivery may be beneficial. PUBLIC HEALTH RELEVANCE: The objectives of this proposal are to develop and evaluate a recombinant tissue plasminogen activator (rt- PA) coated echogenic liposomal formulation for both ultrasound and thrombolysis controlled neuroprotective gas delivery to the cerebral circulation for the treatment of ischemic brain injury in association with thrombotic stroke. This may help overcome problems of incomplete thrombolysis and cerebral ischemia injury seen with current available strategies. Gas encapsulation and delivery technique developed in this research can be translated into entities in which bioactive gas delivery may be beneficial.