Ultrasonically and Iontophoretically Enhanced Drug-Delivery System Based on Dissolving Microneedle Patches

Abstract

A multifunctional system comprised of hyaluronic acid microneedles was developed as an effective transdermal delivery platform for rapid local delivery. The microneedles can regulate the filling amount on the tip, by controlling the concentration of hyaluronic acid solution. Ultrasonication induces dissolution of the HA microneedles via vibration of acoustic pressure, and AC iontophoresis improves the electrostatic force-driven diffusion of HA ions and rhodamine B. The effect of ultrasound on rhodamine release was analyzed in vitro using a gelatin hydrogel. the frequency and voltage dependence of the Ac on the ion induction transfer was also evaluated experimentally. the results showed that the permeability of the material acts as a key material property. The delivery system based on ultrasonication and iontophoresis in microneedles increases permeation, thus resulting in shorter initial delivery time than that required by delivery systems based on passive or ultrasonication alone. This study highlights the significance of the combination between ultrasonic waves and iontophoresis for improving the efficiency of the microneedles, by shortening the reaction duration. We anticipate that this system can be extended to macromolecular and dependence delivery, based on drug response time.

Enhanced Drug Permeation into Human Keloid Tissues by Sonophoresis-Assisted Microneedling

“…However, most previous studies were based on porcine skins 10,11,20,21 or gelatin gels, 22 and only a few were conducted on human normal skin. Since human keloid tissues are characterized by extra collagen deposition and potential epidermis defects, 23 their physical features might be different from those of animal models or human normal skin.…”

“…Furthermore, experiments have shown that the vibration of ultrasound can promote the melting of dissolving MNs and then improve drug delivery efficacy. 22 Thus, MNs assisted with advanced material technology should be further studied in the future. Our future work will focus on improving patients’ treatment experience by developing advanced MN-related strategies in the treatment of pathological scars.…”

Ultrasound-responsive polymer-based drug delivery systems

“…It can be expected that the combination of ultrasound-responsive polymeric formulations with these advanced technologies might further enhance transdermal drug delivery [ 156 , 169 ]. The synergistic combination of microneedles with ultrasound-responsive drug carriers has been reported in 2020: Lim and coworkers utilized an ultrasonically and iontophoretically enhanced transdermal delivery platform that allowed rapid and localized drug delivery [ 170 ]. This platform consisted of hyaluronic acid microneedles that showed an increased dissolution rate under ultrasonic stimulation (1.7 MHz), or under continuous exposure of an electric field.…”

Rapidly Separable Micropillar Integrated Dissolving Microneedles

“…On the other hand, depending on the chemical structures and concentrations of backbone matrices used in the fabrication of DMNs, the dissolution time varies from minutes to hours, leading to inconvenience, irritation, and allergic reactions in some patients [ 15 ]. Therefore, various innovative systems, including double-layered and tip-loaded DMNs, arrow-head DMNs, physical and chemical application enhancers, and DMN applicators, have been developed to overcome the current patch-based DMN limitations [ 16 , 17 , 18 , 19 , 20 , 21 , 22 ]. However, double layer and tip-loaded DMNs are limited by low loading capacity and complexities that limit their use as an optimal platform for DMNs [ 23 , 24 , 25 , 26 ].…”