Porous Metallic Microneedle Array-Based Test Trip for Gingival Crevicular Fluid Collection and Analysis

Periodontal disease is a chronic inflammatory condition that affects the gum tissue and other structures supporting the teeth. Without treatment, it can destroy the alveolar ridge and lead to tooth loss. Gingival crevicular fluid (GCF), as a diagnostic fluid, has been extensively explored in search for potential biomarkers of periodontal disease. Traditionally, GCF is collected using paper strips and then analyzed for its compositions through methods like proteomics or immunoassay. However, paper strip easily loses mechanical strength in the fluid and the collection also takes minutes that often leads to contamination by saliva and blood. In addition, while proteomics and immunoassays can provide a full spectrum of the GCF composition, these methods require professionals and tedious procedure. Therefore, there is a great need to have a technology that can collect GCF with minimal contamination and provide timely analysis of the contained biomarkers.Inspired by the emergence of POC diagnostic devices, we plan to develop a disposable and convenient system that permits the interference-free collection and real-time analysis of GCF. Specifically, the system has the appearance of a test strip, composing of a porous and metallic microneedle array and a biosensing component. When the microneedle array is inserted into the periodontal pocket, GCF will be absorbed via capillary force and flow through the porous microneedle array to the biosensing section. The biosensing component then converts the concentration of a specific biomarker (by taking MMP-8 as a model biomarker) in the GCF to colorimetric signal, which is quantified through a smartphone app. The device will be tested on a rat model of diabetes periodontitis.