Photo-Reversible Polymers for the Opto-Bio Interface

用于光生物界面的光可逆聚合物

• 批准号: RGPIN-2014-06655
• 负责人: Barrett, Christopher
• 金额: $ 3.93万
• 依托单位: McGill University
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 财政年份: 2017
• 资助国家: 加拿大
• 起止时间: 2017-01-01 至 2018-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=632549
• 关键词: Photo; Reversible; Polymers; Opto; Bio

The eventual goal is to design, prepare, and test dye-containing polymers that can be layered onto soft optical fiber ends, that can be micro-positioned in close proximity or even contact with live neural cells to both sense and signal in 2-way communication with them. A 3-pronged approach towards this goal will combine separate projects equally in 3 fields working together of: synthetic organic dye chemistry, polymer and interfacial materials chemistry, and physical fiber optic spectroscopy. All 3 component projects in parallel propose significant advances in each field order for the combined program goals to be realized, yet advances realized in each can be independently valuable. The polymers designed will be soft, wet mimics of real biological tissue and will contain small amounts of sensitive azo dyes that change visibly in the presence of specific neurotransmitters released during synaptic events. Ultimately, this will allow for the fabrication and optimization of an active 2-way interface between live neural cells and optical fibers that sends as well as receives—using similar photo-reversible dyes to release chemical signals back that could stimulate an action potential. Historic attempts towards a working interface between live brain tissue and readout technology invariably used implanted metal micro-electrodes. These are fundamentally invasive surfaces however, and last only hours before rejection is initiated—the neural cells inevitably eventually respond to implanted metal electrodes as foreign objects by enclosing them in astroglial scars that ultimately create a barrier between the electrode and the neural communication mechanisms. The approach outlined here instead is novel in the inherent stable biocompatibility of the soft wet polymers self-assembled at the interface, and in the use of light to sense and signal instead of electrical current. Guiding the approach will be principals of bio-mimicry and self-assembly, where the surface bio-film host polymers mimic real biological tissue in their soft, wet, compliant tune-ability, and the light-responsive shape-changing azo dyes mimic our rhodopsin/retinal systems that enable vision and a direct opto-neural information interface. More specifically, this proposal seeks to extend the reversible photo-switching capability of current azo bio-films into 2-way reversible communication (sensing and signaling), using new multi-functional dyes with pH sensitivities, and pendant boronic acid groups tuned to bind and detect the dopamine class of diol neurotransmitters. Now that cell response has been shown to be able to be triggered by an azo surface, the development challenges and risks here also represent worthwhile goals to achieve: a) entire cell growth to just neural synapse, b) irreversible to reversible, c) 1-way to 2-way communication, d) long pre-irradiation to real-time communiction, e) static switching to dynamic, f) in vitro to in vivo detection, and g) large surface to small fiber.From a practical standpoint these new materials are of interest as ‘smart’ surfaces for sensing, signaling, and controlling adjacent biological activity, due to the combination of soft photochemical functionalities, and their inherent biocompatibility. From the standpoint of fundamental science, these new materials and their study will enable us to contribute to a basic understanding of biological function at the interface between living cells and artificial media, and communication between them, from a chemical and materials perspective. Combined together, this proposal represents an exciting new direction towards achieving a brain-machine interface using nature as the inspiration for both the soft organic materials, and for light as the communication medium.

最终的目标是设计，准备和测试含染料的聚合物，这些聚合物可以分层到柔软的光纤末端，这些聚合物可以密切接近，甚至可以与实时神经元细胞接触，从而在与它们的2路通信中保持感官和信号。实现此目标的三管齐下的方法将在3个工作中平均合并：合成有机染料化学，聚合物和界面材料化学和物理光纤光谱法。并行提案中的所有3个组件项目在每个现场顺序中取得了重大进步，以实现合并的计划目标，但在每个现场方面都可以独立有价值。设计的聚合物将是真实生物组织的柔软，潮湿的模仿，并包含少量敏感的偶氮染料，这些染料在突触事件期间释放出来的特定神经递质的情况下会改变可见。最终，这将允许在活性神经元细胞和发送和接收的光纤之间的活动2向接口的制造和优化 - 使用类似的光可逆染料来释放可能刺激动作电位的化学信号。历史性尝试在活脑组织和读出技术之间进行工作界面，总是使用植入的金属微电极。但是，这些都是侵入性的表面，并且持续数小时在开始排斥反应之前，神经元细胞不可避免地通过将它们封闭在星形胶质疤痕中，从而对植入的金属电子物体反应，从而最终在电子和神经元通信机制之间产生障碍。相反，这里概述的方法是在界面上自组装的软湿聚合物的继承稳定的生物相容性中的新颖性，并且在使用光来感知和信号而不是电流中。指导该方法将是生物模拟和自组装的原理，其中表面生物膜宿主聚合物模仿其柔软，湿，兼容的曲调能力中的真实生物学组织，以及变化的光反应形状变化的azo会染色我们的Rhopopsin/retinal系统，使我们的视觉蛋白/视网膜系统染色和直接的选择性信息界面。更具体地说，该提案旨在使用具有pH敏感性的新型多功能染料以及调谐和检测DIOL神经神经神经固定剂的多巴胺类别的新型多功能染料，将当前AZO Bii-Film的可逆照相转换能力扩展到2个可逆通信（传感和信号）中。 Now that cell response has been shown to be able to be triggered by an azo surface, the development challenges and risks here also represent worthwhile goals to achieve: a) entire cell growth to just neural synapse, b) irreversible to reversible, c) 1-way to 2-way communication, d) long pre-irradiation to real-time communication, e) static switching to dynamic, f) in vitro to in vivo detection, and g) large surface to small 纤维。从实际的角度来看，由于软光化学功能及其继承的生物相容性，这些新材料作为灵敏度，信号传导和控制相邻生物学活动的“智能”表面。从基本科学的角度来看，这些新材料及其研究将使我们能够从化学和材料的角度从生物细胞与人工培养基之间的界面以及它们之间的交流中对生物学功能的基本理解做出贡献。该提案结合在一起，代表着一个令人兴奋的新方向，以使用自然作为柔软有机材料的灵感来实现脑机界面，并以光作为通信介质的灵感。