Bilaterally Aligned Electroosmotic Flow Generated by Porous Microneedle Device for Dual-Mode Delivery.

Here, a novel porous microneedle (PMN) device with bilaterally aligned electroosmotic flow (EOF) enabling controllable dual-mode delivery of molecules is developed. The PMNs placed at anode and cathode compartments are modified with anionic PAMPS (poly-2-acrylamido-2-methyl-1-propanesulfonic acid) and cationic PAPTAC (poly-(3-acrylamidopropyl) trimethylammonium), respectively. The direction of EOF generated by PMN at the cathode compartment is, therefore, reversed from cathode to anode, countering the unwanted cathodal suctioning of interstitial fluid caused by reverse iontophoresis. With the bilateral alignment of EOF, the versatility of the proposed device is evaluated by delivering molecules with different charges and sizes using Franz Cell. In addition, a 3D printed probe device is developed to ease practical handling and minimize electrical stimulation by integrating two PMNs in closed proximity, demonstrated by dual delivery of a variety of molecules (methylene blue, rhodamine B and FITC-dextran) using pig skin and vaccination using mice with delivered ovalbumin. This article is protected by copyright. All rights reserved.