In Vitro Assay to Assess Chemical Toxicity in Retinal Primary Cell Cultures

描述（由申请人提供）：美国普通人体内含有可检测水平的100多种工业化合物、污染物和化学品，但预测这种暴露的相对风险，特别是随着时间的推移，是具有挑战性的（US CDC，2003）。成功开发和商业化的下一代，低成本，高性能的技术预测化合物的毒性将有助于评估安全水平的环境安全，从而降低国家的医疗保健成本和生产更安全的工作/生活环境。这种暴露于环境毒素在衰老和氧化过程中起着重要作用，这是黄斑变性的关键风险因素，这一过程最终导致失明。然而，重要的是，目前没有可接受的或实际的测试用于直接测量化合物的视网膜毒性。视网膜毒性的体内评估在进行时需要大量的动物，是耗时且昂贵的，并且不提供关于毒性进展的数据。在体外制备稳定的原代混合视网膜培养物的能力将允许以快速和具有成本效益的方式筛选和优先考虑进一步的毒性测试。理想情况下，这种系统应允许区分光依赖性毒性[光毒性]和一般毒性作用，并模拟体内毒性。因此，该多阶段SBIR项目的总体目标是开发、验证和商业化Ocuscreen（TM），Acucela的专有视网膜培养筛选系统，作为下一代体外系统，用于对环境毒素的相对（光）毒性进行排名，并将该测定作为化学品商业化监管框架的一部分。本项目第I阶段的具体目标是识别一组已知的视网膜毒物，证明对其（光）毒性潜力进行排名的可行性，并最终显示这些排名与体内文献数据相关。证明我们可以在一小类代表性化合物中预测（光）毒性（或缺乏毒性）将在第一阶段概念验证项目的有限范围内建立我们新系统的预测潜力，并将为更大的第二阶段演示工作奠定基础。第一阶段还将为Ocuscreen被提名为替代方法验证机构间协调委员会（ICCVAM）的替代测试方法提供足够的数据，并将使我们能够确定Ocuscreen符合ICCVAM性能标准的程度。第二阶段的工作将涉及建立一个大型的感光毒性数据库的化学品，建立从现有的知识和结果，从我们的分析系统，以提高预测的准确性化合物的安全性。该项目的第三阶段将侧重于建立感光体毒性的商业筛查服务。即使没有正式的法规采用，准确预测潜在毒性的能力也将为化学公司提供引人注目的服务，并将代表保护人类健康的重要一步。在美国，普通人体内含有可检测到的100多种工业化合物、污染物和化学物质，但预测这种暴露的风险，特别是眼毒性，是一项挑战。目前的预测方法需要大量的动物，是耗时和昂贵的，并没有提供关于毒性进展的数据。该项目的总体目标是开发、验证和商业化Acucela专有的视网膜培养筛选系统，作为下一代实用的体外系统，用于评估环境毒物对健康的影响。

DESCRIPTION (provided by applicant): The average person in the U.S. contains detectable levels of more than 100 industrial compounds, pollutants, and chemicals, but predicting the relative risk of this exposure, especially over time, is challenging (US CDC, 2003). Successful development and commercialization of next-generation, low-cost, high-performance technology for predicting compound toxicity would help assess safe levels of environmental exposure-thereby reducing national healthcare costs and producing safer working/living environments. This exposure to environmental toxins plays an important role in aging and oxidation processes, which are key risk factors of macular degeneration, a process that eventually leads to blindness. Importantly, however, there are currently no accepted or practical tests for measuring the retinal toxicity of compounds directly. In vivo assessments of retinal toxicity, when performed, require large numbers of animals, are time-consuming and expensive, and do not provide data on toxicity progression. The ability to prepare stable primary mixed retinal cultures in vitro would allow screening and prioritization of further toxicity testing in a rapid and cost-effective manner. Ideally, such a system should allow differentiation of light-dependent toxicity [phototoxicity] and general toxic effects, and would mimic in vivo toxicity. Therefore, the overall goal of this multi-phase SBIR project is to develop, validate, and commercialize Ocuscreen(tm), Acucela's proprietary retinal culture screening system, as a next-generation in vitro system for ranking the relative (photo)toxicity of environmental toxins, and to have this assay incorporated as a part of the regulatory framework for the commercialization of chemicals. The Specific Aims for Phase I of this project are to identify a group of known retinal toxicants, to prove the feasibility of ranking their (photo)toxic potential, and finally to show these rankings correlate with in vivo literature data. Demonstrating that we can predict (photo)toxicity (or lack thereof) in a small class of representative compounds will establish the predictive potential of our new system within the limited scope of the Phase I proof-of-concept project, and will set the stage for a larger Phase II demonstration effort. Phase I will also provide sufficient data for Ocuscreen to be nominated as an alternative test method to the Interagency Coordinating Committee on the Validation of Alternative Methods (ICCVAM), and will allow us to determine how well Ocuscreen meets ICCVAM performance standards. Phase II work will involve establishing a large photoreceptor toxicity database of chemicals-built both from existing knowledge and results from our assay system-to improve the predictive accuracy of compound safety. Phase III of the project will be focused on establishing a commercial screening service for photoreceptor toxicity. Even without formal regulatory adoption, the ability to accurately predict toxic potential will provide a compelling service to chemical companies and will represent an important step in protecting human health. The average person in the U.S. contains detectable levels of more than 100 industrial compounds, pollutants, and chemicals, but predicting the risk of this exposure, especially to eye toxicity, is challenging. Current prediction methods require large numbers of animals, are time-consuming and expensive, and do not provide data on toxicity progression. The overall goal of this project is to develop, validate, and commercialize Acucela's proprietary retinal culture screening system as a next-generation, practical in vitro system for evaluating the health effects of environmental toxicants.