Department of Bioengineering, University of California, San Diego, La Jolla, California 92093, United States.
Department of Nanoengineering, University of California, San Diego, La Jolla, California 92093, United States.
ACS Sens. 2020 Mar 27;5(3):686-692. doi: 10.1021/acssensors.9b01812. Epub 2020 Mar 10.
Currently, traumatic brain injury (TBI) is detected by medical imaging; however, medical imaging requires expensive capital equipment, is time- and resource-intensive, and is poor at predicting patient prognosis. To date, direct measurement of elevated protease activity has yet to be utilized to detect TBI. In this work, we engineered an activity-based nanosensor for TBI (TBI-ABN) that responds to increased protease activity initiated after brain injury. We establish that a calcium-sensitive protease, calpain-1, is active in the injured brain hours within injury. We then optimize the molecular weight of a nanoscale polymeric carrier to infiltrate into the injured brain tissue with minimal renal filtration. A calpain-1 substrate that generates a fluorescent signal upon cleavage was attached to this nanoscale polymeric carrier to generate an engineered TBI-ABN. When applied intravenously to a mouse model of TBI, our engineered sensor is observed to locally activate in the injured brain tissue. This TBI-ABN is the first demonstration of a sensor that responds to protease activity to detect TBI.
目前，创伤性脑损伤（TBI）是通过医学成像来检测的；然而，医学成像需要昂贵的资本设备，耗时耗力，并且预测患者预后的能力较差。迄今为止，尚未利用蛋白酶活性的直接测量来检测 TBI。在这项工作中，我们设计了一种用于 TBI 的基于活性的纳米传感器（TBI-ABN），该传感器可响应脑损伤后开始的蛋白酶活性增加。我们确定钙敏感性蛋白酶钙蛋白酶-1在损伤后数小时内活跃于受损大脑中。然后，我们优化了纳米级聚合物载体的分子量，使其以最小的肾滤过进入受损脑组织。将一种在切割时产生荧光信号的钙蛋白酶-1 底物附着到这种纳米级聚合物载体上，以生成工程化的 TBI-ABN。当将其施用于 TBI 的小鼠模型时，我们设计的传感器被观察到在受损的脑组织中局部激活。这种 TBI-ABN 是第一个响应蛋白酶活性以检测 TBI 的传感器的证明。
