Microneedles integrated with a triboelectric nanogenerator: an electrically active drug delivery system

Abstract

In this study, a combined system of microneedles and a triboelectric nanogenerator (TENG) has been developed for drug delivery. A triboelectric device, which converts mechanical energy into alternating current (AC), was chosen to replace the electrophoresis (EP) effect. To directly generate triboelectricity from salmon deoxyribonucleic acid (SDNA)-based microneedles, a triboelectric series of SDNA film and chargeable polymers (polyimide and Teflon) was studied. The electrical output of the two charged polymers was compared to find a material that could be highly charged with SDNA. The electrical output was also compared as a function of the concentration of a drug embedded in the SDNA film, and the results confirmed that drug intercalation affected the carrier diffusion. The mechanical strength of the microneedles was assessed by histological analysis of their penetration into porcine cadaver skin. Furthermore, the output voltage of a system incorporating microneedles and TENG in cadaver skin, and in vitro drug release into gelatin were evaluated to examine potential application as an electrically active drug delivery system. The electrical output voltage of this system was ∼95 V. The mechanism of triboelectric perturbation to the skin has also been discussed. The system developed in this work is a new, facile approach toward effective drug delivery that replaces the existing EP method and expands the application of TENGs.

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

“…PDMS (Sylgard 184; Dow Corning, Midland, MI, USA) prepared by mixing elastomer and curing agent in a ratio of 10: 1 was poured onto a master stamp. The molds were cured at 50 °C for 2 h. The PDMS mold was then separated from the stamp 10,11,42 .…”

“…In vitro drug release. Gelatin hydrogel (10 wt%; Sigma Aldrich, gel strength ~300 g Bloom, Type A) derived from porcine skin was used as the model tissue for the drug release studies 11,43 . The polymer membrane (Parafilm M, American National Can, Chicago, IL) was pierced with microneedles and placed on the hydrogel surface.…”

“…It can effectively deliver drugs or active ingredients to the skin by crossing over the stratum corneum [5][6][7][8][9][10][11] . Among the various types of microneedles [5][6][7][8][9][10][11] , dissolving microneedles are made of a water-soluble polymer that exhibits excellent biocompatibility. The dissolving microneedles penetrate the skin and get dissolved by the fluid in the skin to deliver drugs or effective ingredients 8,10,11 .…”

“…Among the various types of microneedles [5][6][7][8][9][10][11] , dissolving microneedles are made of a water-soluble polymer that exhibits excellent biocompatibility. The dissolving microneedles penetrate the skin and get dissolved by the fluid in the skin to deliver drugs or effective ingredients 8,10,11 . On the other hand, the cavitation phenomenon is applied during ultrasound-mediated drug delivery.…”

Effective Dispensing Methods for Loading Drugs Only to the Tip of DNA Microneedles

“…In addition, our group developed a drug delivery system with salmon DNA and hyaluronic acid drug-embedded MNs, and achieved higher drug delivery efficiency by applying physical enhancers, including electricity, ultrasound, and combinations thereof [ 26 , 27 , 28 ]. However, we found that it is also critical to efficiently control the amount of drugs delivered to the body and avoid unnecessary drugs (like drugs on the patch backplate) [ 29 ].…”