Microneedle Patch Provides Early Warning of Adverse Antidiuretic Drug Effect

Frequent nighttime bathroom visits can raise the risk of falls in seniors. Synthetic antidiuretic hormone drugs can be used as a treatment, but they are associated with their own risk, i.e., the dangerous syndrome of inappropriate antidiuretic hormone secretion (SIADH). SIADH leads to fluid retention, disrupting the balance of sodium and uric acid and decreasing concentrations. In severe cases, this can cause adverse effects such as lethargy, coma, or acute renal failure. Thus, monitoring sodium ion and uric acid level changes during treatment is necessary for the safe use of this type of drug.

Jianlong Wang, Chinese Academy of Medical Sciences, Beijing, Lei Su, Xueji Zhang, Shenzhen University, China, and colleagues have developed a smart, wearable, microneedle array-based colorimetric sensor to detect in vivo interstitial fluid (ISF) sodium ions and uric acid alterations. Interstitial fluid is formed by blood filtration through capillary vessels and can be collected safely. The sensor’s accuracy is enhanced by using a convolutional neural network (CNN), a class of deep learning algorithms that are particularly well-suited for processing and analyzing visual data.

The sensor is composed of a vacuum tube-driven microneedle array patch and a built-in colorimetric sensing paper, enabling an efficient ISF extraction and rapid colorimetric assay. Using self-designed CNNs, the sensor efficiently eliminates the influence of ambient light on colorimetric outcomes, allowing for a rapid and accurate read-out of the colorimetric result. The team collected over a thousand colorimetric results under different light conditions to train the self-designed CNN model for classification in non-standard lighting environments.

The resulting CNN model achieved a high accuracy for sodium ion (> 99 %) and uric acid (> 98 %) concentrations. Overall, the work could provide a tool for assisting the elderly in monitoring their health status, provide early warning of SIADH, and help to ensure safety for the use of synthetic antidiuretic drugs.