Conductive Microneedle Patch with Electricity-Triggered Drug Release Performance for Atopic Dermatitis Treatment

Atopic dermatitis (AD) is a chronic inflammatory skin disease that seriously affects the life quality of patients. Topical administration of glucocorticoids is considered to be the most effective anti-inflammatory treatment. However, due to the barrier function of skin, only less than 20% of topical drug molecules could diffuse into the skin. Therefore, it is of great importance to develop an effective strategy to improve AD therapy. In this study, we reported a two-electrode microneedle patch (t-EMNP) composed of a polylactic acid–platinum (PLA-Pt) MN array and polylactic acid–platinum–polypyrrole (PLA-Pt-PPy) MN array for improving the transdermal drug delivery efficacy. The drug loading capability of MNs could be altered by employing different polymerization times and drug concentrations. The drug release rate of MNs could be changed by applying different voltages. We further developed a controlled transdermal drug delivery system (c-TDDS) based on this two-electrode microneedle patch (t-EMNP), exhibiting the remarkable performance of the electricity-triggered drug release profile. The drugs could be released with electrical stimulation, while there was almost no drug release without electrical stimulation. For AD treatment in vivo, this MN patch with electricity-triggered drug release performance could effectively deliver more drugs into the skin compared with other controls such as dexamethasone cream, which efficiently alleviate AD. In sum, this work not only developed a smart patch for improving AD treatment but also provided a promising approach of transdermal drug delivery on demand.