Next Generation Oxime Therapeutic for Chemical Agent Inhibited CNS (Brain) ChEs

用于化学制剂抑制中枢神经系统（脑）ChE 的下一代肟疗法

• 批准号: 7224473
• 负责人: Richard K. Gordon
• 金额: $ 59.95万
• 依托单位: GENEVA FOUNDATION
• 依托单位国家: 美国
• 财政年份: 2006
• 资助国家: 美国
• 起止时间: 2006-09-30 至 2011-05-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7224473
• 关键词: brain

DESCRIPTION (provided by applicant): Current treatment of acute pesticide or organophosphate (OP) poisoning includes a combined administration of a cholinesterase reactivator (oxime), a muscarinic receptor antagonist (atropine) and an anticonvulsant (diazepam). Since the oxime does not penetrate the blood brain barrier (BBS), removal of excessive accumulation of acetylcholine (ACh) is not accomplished by acetylcholinesterase (AChE). Pesticides and OPs are significant terrorist threats to civilian populations. The chemical agent sarin was used in the Tokyo subway terrorist event in 1995 and resulted in long-term neuronal sequelae. Clearly, a new formulation of oxime is required to improve CNS therapy. Because of their chemical structure, the positively charged small molecule oximes do not penetrate the BBB and therefore can not treat pesticide- and OP- induced toxicity in the brain. Our long term goal is to transport oxime (2-PAM, MMB-4) quickly and non-invasively into the CNS. CNS-penetrating oxime therapy will reactivate the brain AChE in a timely manner, reduce the requirement for anticonvulsant drug regimens, and improve the long term recovery of the exposed individual by reducing or eliminating CNS neuronal damage, (a) We will synthesize and evaluate more lipoidal forms (pro-oximes), that can be converted to their active (charged) form in the brain, (b) In addition, we will develop carrier(s) of oximes that will come from a class of FDA approved/phase 1 trial Pharmaceuticals that pass the BBB for treatment of CNS dancers, including Stealth liposomes, nanoparticles, or cyclodextrins. (c) Two additional advantages to the carriers: should permit a sustained delivery of oxime into the systemic circulation through the skin (via skin patch) and prolong the circulatory time of the oxime(s), which are rapidly cleared by the renal system (T1/2<2 hr). (d) For formulations that are successful in in vitro BBB tissue culture and pig skin penetration models, we will determine reactivation kinetics of the encapsulated oximes with pesticide- and OP-inhibited AChE and BuChE, the release rates of the oxime from the carrier in the peripheral and CNS of our animal model (guinea pig), and the pharmacokinetics of the pro-oxime and oxime carrier and distribution in diaphragm, blood, and brain, (d) The most efficacious formulation will be validated in our status epilepticus guinea pig model as a therapy for CNS chemical agent OP-induced toxicity of DFP, GB, GD, and VX using EEC radiotelemetry probe techniques. This program will address an important and potential threat to civilian populations, for post-exposure CNS treatment in response to exposure to chemical threat agents. Further, the outcome of this work could provide a non-invasive means of administrating appropriate therapeutics for deleterious effects of OP poisoning, directly relevant to emergency and preparedness response to chemical threats for Public Health.

描述（由申请人提供）：目前对急性农药或有机磷（OP）中毒的治疗包括联合施用胆碱酯酶再激活剂（肟）、毒蕈碱受体拮抗剂（阿托品）和抗惊厥药（地西泮）。由于肟不能穿透血脑屏障 (BBS)，因此乙酰胆碱酯酶 (AChE) 无法去除过量积累的乙酰胆碱 (ACh)。农药和有机磷农药是对平民的重大恐怖威胁。 1995年东京地铁恐怖事件中使用的化学毒剂沙林造成了长期的神经后遗症。显然，需要一种新的肟配方来改善中枢神经系统治疗。由于其化学结构，带正电荷的小分子肟不能穿透血脑屏障，因此不能治疗农药和有机磷农药引起的脑毒性。我们的长期目标是将肟（2-PAM、MMB-4）快速、无创地输送到中枢神经系统。 CNS穿透性肟疗法将及时重新激活大脑AChE，减少抗惊厥药物治疗的需要，并通过减少或消除CNS神经元损伤来改善暴露个体的长期恢复，（a）我们将综合和评估更多类脂形式（前肟），可以在大脑中转化为活性（带电）形式，(b) 此外，我们将开发肟载体，来自 FDA 批准/一期试验的一类药物，通过了用于治疗中枢神经系统舞者的 BBB，包括隐形脂质体、纳米颗粒或环糊精。 (c) 载体的另外两个优点：应允许肟通过皮肤（通过皮肤贴片）持续输送到体循环中，并延长肟的循环时间，肟被肾系统迅速清除。 T1/2<2 小时）。 (d) 对于在体外 BBB 组织培养和猪皮肤渗透模型中成功的制剂，我们将确定具有农药和 OP 抑制的 AChE 和 BuChE 的封装肟的再激活​​动力学，以及肟从载体中的释放速率。我们的动物模型（豚鼠）的外周和中枢神经系统，以及原肟和肟载体的药代动力学以及在膈肌、血液和大脑中的分布，（d）使用 EEC 无线电遥测探针技术，将在我们的癫痫持续状态豚鼠模型中验证有效的制剂作为 CNS 化学剂 OP 诱导的 DFP、GB、GD 和 VX 毒性的治疗方法。该计划将解决对平民的重要和潜在威胁，进行暴露后中枢神经系统治疗，以应对化学威胁剂的暴露。此外，这项工作的成果可以提供一种非侵入性方法，对OP中毒的有害影响进行适当的治疗，与公共卫生化学威胁的紧急情况和准备反应直接相关。