Dissolving Microneedle Patch Integrated with Microspheres for Long-Acting Hair Regrowth Therapy.

Androgenetic alopecia (AGA) is the most common type of progressive hair loss in both men and women that severely reduces life quality and affects patients' self-esteem. Due to the shortcomings of traditional therapeutic formulations (e.g., topical minoxidil and oral finasteride), such as low bioavailability, frequent dosing, and significant side effects, there is an urgent need to develop a safe and effective strategy for AGA treatment. Here, we report a water-soluble microneedle (MN) patch integrated with biodegradable minoxidil (MXD)-loaded microspheres for long-acting AGA treatment with reduced administration frequency and improved patient compliance. When the patch pierces the skin, the MNs rapidly dissolve and deliver MXD-encapsulated polylactic- co -glycolic acid (PLGA) microspheres into the skin, which, subsequently act as drug reservoirs for the sustained release of the therapeutics for over 2 weeks. Additionally, the application of the MN patch provided a mechanical stimulation on mouse skin, which was also helpful for hair regrowth. Compared with the topical MXD solutions that have been commercialized on the market and require daily application, the long-acting MN patch contains a much lower drug amount and shows a similar or superior hair regeneration effect in AGA mice while only requiring monthly or weekly administration. These encouraging results suggest a simple, safe, and effective strategy for long-acting hair regeneration in clinics.