Highly Swellable Microneedles to Rapidly Extract Skin Interstitial Fluid for for Timely Metabolic Analysis
XU Chenjie
Associate Professor
Department of Biomedical Engineering, City University of Hong Kong
chenjie.xu@cityu.edu.hk
Abstract
Hydrogel microneedle patch enables the withdrawal of skin interstitial fluid (ISF) through in situ swelling in a minimally invasive manner without assistance of extra devices. However, existing hydrogel microneedles require tens of minutes to collect sufficient volume (>1 mL) for effective analysis. This study introduces an osmolyte-powered hydrogel microneedle patch that can extract ISF three times faster than the existing platforms. The microneedle patch is composed of osmolytes (i.e. maltose) and hydrogel (i.e. methacrylated hyaluronic acid) and made through the template-molding method. Once in the skin, hydrogel swells while ISF diffuses through dermis and then partitions into the hydrogel matrix. Along the process, the osmolytes dissolve in the matrix and provide osmotic pressure to increase the diffusion of ISF from skin to the hydrogel matrix. The patch with 100 microneedles can extract 7.90 μL of ISF from pig skin ex vivo and 3.82 μL of ISF from mouse skin in vivo within 3 minutes while the control (i.e. hydrogel microneedle without osmolytes) requires >10 minutes to achieve similar results. Finally, the extracted ISF allows the quantification of biomarkers like glucose and cholesterol and drugs like insulin in vivo through integration with the 3D printed wearable electronics.
Short Bio
Dr. XU is an associate professor of biomedical engineering at City University of Hong Kong, adjunct principal investigator at National Dental Centre of Singapore. He is dedicated to the development of transdermal drug delivery formulations and devices (especially nucleic acid-based nanoparticles and microneedle-based skin patch). He is well known for the development of skin patch for keloid treatment, anti-obese skin patch, skin patch for skin interstitial fluid extraction etc. He has published more than 140 peer-reviewed articles (citation is 11k with H index of 45), edited two books, holding 10 international patents. His research is supported by a wide range of public and private foundations including Singapore Minister of Education, Singapore A*Star, Continental Corp (German), Bill & Melinda Gates Foundation, Hong Kong University Grants Committee, National Natural Science Foundation of China, etc.