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

• Published in: Advanced healthcare materials 2024-09, Vol.13 (22), p.e2401181-n/a
• Main Authors: Wang, Gaobo, Kato, Kosuke, Ichinose, Sae, Inoue, Daisuke, Kobayashi, Airi, Terui, Hitoshi, Tottori, Soichiro, Kanzaki, Makoto, Nishizawa, Matsuhiko
• Format: Article
• Language: English
• Subjects: Cathodes; Controllability; Dextran; Dextrans; drug administration; dual delivery; Electrical stimuli; Electroosmosis; electroosmotic flow; Fluorescein isothiocyanate; Iontophoresis; Methylene blue; Needles; Ovalbumin; Pigskins; porous microneedle; Rhodamine; Vaccination
• ISSN: 2192-2640; 2192-2659; 2192-2659
• DOI: 10.1002/adhm.202401181

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 poly‐2‐acrylamido‐2‐methyl‐1‐propanesulfonic acid and cationic 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. Finally, the performance of the integrated probe device is demonstrated by dual delivery of a variety of molecules (methylene blue, rhodamine B, and fluorescein isothiocyanate–dextran) using pig skin and vaccination using mice with delivered ovalbumin. Dual‐mode drug delivery using an integrated porous microneedle device generating aligned electroosmosis flow is developed. Two semicircular porous microneedles placed at anode and cathode compartments are modified with anionic poly‐2‐acrylamido‐2‐methyl‐1‐propanesulfonic acid and cationic poly‐(3‐acrylamidopropyl) trimethylammonium, respectively. Therefore, the alignment of electroosmotic flow toward the skin effectively mitigates the unwanted cathodal interstitial fluid suction by inducing a counterflow for reverse iontophoresis.