Wearable Sensor Patch with Hydrogel Microneedles for In Situ Analysis of Interstitial Fluid

Microneedle-integrated distance-based paper device for simultaneous transdermal detection of cortisol and dopamine

Accurate measurement of stress marker cortisol and neurotransmitter dopamine is essential for understanding the physiological effects of chronic stress, enabling early therapeutic interventions to prevent adverse health consequences. Herein, we introduce the first fully integrated wearable device comprising a microneedle (MN) patch and distance-based paper analytical device (dPAD) for minimally invasive dermal interstitial fluid (ISF) sampling and simultaneous cortisol and dopamine sensing. The MN patch employs a swellable hydrogel matrix for efficient ISF extraction, whereas the simple dPAD sensor can simultaneously detect cortisol and dopamine through colorimetric reactions. Quantitative analysis was achieved through simple measurement of the colored distance proportional to the analyte concentration using a ruler. The device demonstrates high sensitivity, with detection limits of 0.25 μg mL-1 for cortisol and 1.0 ng mL-1 for dopamine, along with excellent selectivity for both analytes. It also exhibited high accuracy and precision, with recovery rates of 98.5-100.7% for cortisol and 98.8-102.2% for dopamine. These results show that the developed sensor device is user-friendly, simplifies the analysis process, reduces costs, and eliminates the need for complex instrumentation, making it a promising tool for point-of-care (POC) testing for stress and its relative disorders, with potential applications in diagnosing other biomarkers.

The Past and Future of Sleep Medicine

The past of sleep medicine is rich with seminal discoveries, from the recognition of clinical syndromes to measurement of sleep itself to classic and novel therapeutics. Advances in neurobiology have mapped a number of sleep circuits, described the central and peripheral circadian system, and identified the cause of narcolepsy with cataplexy. Sleep apnea endotypes and phenotypes now have established clinical relevance, though treatment implications are a work in progress. Artificial intelligence will continue to change sleep medicine in a number of domains from aiding scoring to health outcome predictions. There is a large gap between the known science and clinical translational.

Harnessing the role of microneedles as sensors: current status and future perspectives

In recent years, microneedles (MNs) have been transformed to serve a wide range of applications in the biomedical field. Their role as sensors in wearable devices has provided an alternative to blood-based monitoring of health and diagnostic methods. Hence, they have become a topic of research interest for several scientists working in the biomedical field. These MNs as sensors offer the continuous monitoring of biomarkers like glucose, nucleic acids, proteins, polysaccharides and electrolyte ions, which can therefore screen for and diagnose disease conditions in humans. The present review focuses on types of MN sensors and their applications. Various clinical trials and bottlenecks of MN R&D are also discussed.

Polymeric Microneedles for Health Care Monitoring: An Emerging Trend

Bioanalyte collection by blood draw is a painful process, prone to needle phobia and injuries. Microneedles can be engineered to penetrate the epidermal skin barrier and collect analytes from the interstitial fluid, arising as a safe, painless, and effective alternative to hypodermic needles. Although there are plenty of reviews on the various types of microneedles and their use as drug delivery systems, there is a lack of systematization on the application of polymeric microneedles for diagnosis. In this review, we focus on the current state of the art of this field, while providing information on safety, preclinical and clinical trials, and market distribution, to outline what we believe will be the future of health monitoring.