Engineering approaches for point-of-care diagnosis of inner ear disorders based on the detection of blood biomarkers

内耳细胞的永久性损伤会导致听力和平衡障碍。目前还没有诊断测试可以确定内耳细胞损伤的确切位置。因此，对基于内耳循环血液生物标志物检测的新诊断方法的需求尚未得到满足。在提出的研究中，我们的目标是首次开发用于快速检测和定量内耳血液生物标志物（包括特定细胞，基因，抗体或蛋白质）的即时（POC）生物传感器平台。我们将通过开发生物标志物识别策略，如抗体、肽或基于适配体的偶联机制，探索内耳生物标志物的POC诊断平台的非特征属性，用于特定靶标捕获，设计用于快速超灵敏电化学检测血液中目标生物标志物的单步分析。(3)用于小样本体积、低浓度、多种目标血液生物标志物检测的便携式一次性纸装置样机。本提案的长期目标是建立一个内耳及其他部位的综合诊断平台。

Permanent damage to the inner ear cells leads to hearing and balance disorders. There is no diagnostic test available to identify the exact location of cellular damage in the inner ear. Thus, the need for new diagnostic methods based on the detection of inner ear circulating blood biomarkers is unmet. In the proposed research, we aim to develop for the first time, point-of-care (POC) biosensor platforms for the rapid detection and quantification of inner ear blood biomarkers including specific cells, genes, antibodies, or proteins. We will explore the uncharacterized attributes of the POC diagnostic platform for the identified inner ear biomarkers throughout the development of biomarker recognition strategies such as antibody, peptide, or aptamer-based conjugation mechanisms for specific target capturing, design of single-step assays for rapid ultra-sensitive electrochemical detection of the target biomarkers in blood, (3) portable disposable paper device prototype for detection of multiple target blood biomarkers at low concentration in small sample-volumes. The long-term objective of this proposal is to build a comprehensive diagnostic platform for the inner ear and beyond. Recent reports indicated few inner ear protein biomarkers, such as serum prestin and otolin-1 as indicators of inner ear disorders. However, the detection methods for accurately measuring these proteins are based on the conventional multi-step time-consuming quantification processes. We will design electrochemical biosensors to achieve high levels of sensitivity, signal selectivity, and rapidness with the ease of calibration. We will implement the surface-immobilized assays that are compatible with real samples to achieve the target selectivity through DNA hybridization, antibody conjugation, or protein-protein interactions. In addition, with the design of high-curvature nanostructured electrodes with large surface areas, we aim to improve the detection limits in small sample volumes. Furthermore, top-down and bottom-up approaches will be used to develop various microfluidic substrates made of glass or paper with addressable channels and electrodes. We will conduct our research using molecular synthesis and conjugation techniques, electrochemical fabrication and printing techniques, as well as characterization methods. Ultimately, more accurate diagnostics through the detection of blood biomarkers will help identify the sites of damage in the inner ear sensory hair cells, auditory neurons, etc. This will provide the ability to diagnose and monitor the occurrence and progression of a variety of inner ear disorders as well as the efficacy of treatment. While the initial design of the POC biosensing platform is for the detection of inner ear protein biomarkers, several clinically relevant circumstances would benefit from such an approach for the rapid early-stage diagnosis.