Biostable nucleic acid aptamers for long-duration, in vivo molecular monitoring

摘要电化学，适体为基础的（EAB）传感器是一种微创技术已经显示 以支持秒级分辨的实时体内分子测量，而不管化学反应性如何 它的目标。也就是说，EAB传感器是唯一的实时分子测量技术， 同时（1）可推广到药物和生物标志物和（2）证明在体内原位起作用。在 支持这些说法，作为初步结果，我们已经报告了有史以来第一次秒-（甚至亚秒） 多种药物和蛋白质生物标志物的解析的体内测量。这些测量方法， 75微米直径的传感器原位放置在清醒、自由运动的人的血液（颈静脉）和组织（大脑、肌肉）中 大鼠，达到临床相关的准确性，精密度和特异性在数小时的过程。剩余 然而，技术上的限制仍然阻碍了EAB传感器的进一步临床测试： 在体内约5 h，适体降解开始显著降低EAB精度。这里描述的R21项目 是专注于解决这个问题。具体来说，在这里，我们建议引入抗降解， 将非天然XNA适体引入EAB平台作为实现多日体内分子生物学特性的手段。 测量.这项工作的成功完成将为R 01规模的项目奠定基础， 确定长期EAB测量的临床价值，例如，反馈控制 在多天疗程内提供窄治疗指数抗生素，并实时监测 在ICU中的诊断性细胞因子在感染的多日临床过程中，例如在败血症和COVID-19中。

Summary. Electrochemical, aptamer-based (EAB) sensors are a minimally invasive technology already shown to support seconds-resolved, real-time, in vivo molecular measurements irrespective of the chemical reactivity of its targets. That is, EAB sensors are the only real-time molecular measurement technology that is simultaneously (1) generalizable to drugs and biomarkers and (2) demonstrated to work in situ in the body. In support of these claims, as preliminary results we have reported the first ever seconds- (and even sub-second) resolved, in-vivo measurements of multiple drugs and protein biomarkers. These measurements, which employ 75-µm-diameter sensors placed in situ in the blood (jugular) and tissues (brain, muscle) of awake, freely moving rats, achieve clinically relevant accuracy, precision and specificity over the course of hours. A remaining technological limitation, however, still precludes the further clinical testing of EAB sensors: after more than after ~5 h in vivo, aptamer degradation begins to reduce EAB precision significantly. The R21 project described here is focused on solving this problem. Specifically, here we propose the introduction of degradation-resistant, non-natural XNA aptamers into the EAB platform as a means achieving multi-day in vivo molecular measurements. Successful conclusion of this work would set the stage for R01-scale projects aimed at ascertaining the clinical value of long-duration EAB measurements in, for example, the feedback-controlled delivery of narrow-therapeutic-index antibiotics over multi-day treatment courses and the real-time monitoring of diagnostic cytokines in the ICU over the multi-day clinical course of infections, such as in sepsis and COVID-19.