Hydrogel Microfilaments toward Intradermal Health Monitoring

• Published in: iScience Vol. 21; pp. 328 - 340
• Main Authors: Tejavibulya, Nalin, Colburn, David A.M., Marcogliese, Francis A., Yang, Kyung-Ae, Guo, Vincent, Chowdhury, Shilpika, Stojanovic, Milan N., Sia, Samuel K.
• Format: Journal Article
• Language: English
• Published: United States Elsevier Inc 22.11.2019; Elsevier
• Subjects: Bioelectronics; Biomedical Materials; Polymers; Bioelectronics; Polymers; Biomedical Materials
• ISSN: 2589-0042; 2589-0042
• DOI: 10.1016/j.isci.2019.10.036

Digital health promises a paradigm shift for medicine where biomarkers in individuals are continuously monitored to improve diagnosis and treatment of disease. To that end, a technology for minimally invasive quantification of endogenous analytes in bodily fluids will be required. Here, we describe a strategy for designing and fabricating hydrogel microfilaments that can penetrate the skin while allowing for optical fluorescence sensing. The polyacrylamide formulation was selected to provide high elastic modulus in the dehydrated state and optical transparency in the hydrated state. The microfilaments can be covalently tethered to a fluorescent aptamer to enable functional sensing. The microfilament array can penetrate the skin with low pain and without breaking, contact the dermal interstitial fluid, and be easily removed from the skin. In the future, hydrogel microfilaments could be integrated with a wearable fluorometer to serve as a platform for continuous, minimally invasive monitoring of intradermal biomarkers. [Display omitted] •Polyacrylamide hydrogel microfilaments were fabricated via replica molding•Microfilaments are stiff, when dehydrated, and optically transparent, when hydrated•Fluorescent aptamer can be tethered to hydrogel matrix for in situ analyte sensing•Microfilaments penetrate skin with low pain and contact interstitial fluid Bioelectronics; Polymers; Biomedical Materials