Sampling of disease biomarkers from skin for theranostic applications.

Dermatological diseases including psoriasis, eczema, infections, and cancer collectively constitute a large category of human conditions. The large area and ease of access of skin open excellent opportunities for theranostic applications, that is, diagnosis as well as therapy of the disease. Such applications can be based on evaluation of skin's molecular composition in terms of proteins, nucleic acids, and small molecules. Currently, however, such molecular information is not used in clinical practice. To bring this molecular information to routine clinical dermatology, it is essential to develop convenient and minimally invasive methods for rapid sampling molecules from skin. Here, we demonstrate an ultrasonic sampling technique that can recover a wide variety of biomolecules from skin in a minimally invasive manner. We show that ultrasound can retrieve nearly all major tissue constituents, including structural and functional proteins (cytokines, keratins, etc.), lipids (polar and non-polar lipids), and nucleic acids (DNA and RNA). Comparative analyses of skin's molecular constituents obtained by ultrasonic sampling and skin homogenate showed high resemblance between the two biomolecular profiles, enabling us to build a unique molecular signature of skin. Using different mouse models of dermatological conditions, the ultrasonic analysis for changes in the molecular composition of skin confirmed specific regulation of several established biomarkers.