Promotion of Hair Regrowth by Transdermal Dissolvable Microneedles Loaded with Rapamycin and Epigallocatechin Gallate Nanoparticles

The study tested a dissolvable microneedle device loaded with rapamycin and epigallocatechin gallate nanoparticles for promoting hair regrowth. The device was tested on 45 C57BL/6 mice, divided into nine groups. The microneedles penetrated the skin to a depth of 400-450 μm, dissolved within 60 seconds, and released the drugs into the hair follicle niche. This process induced the transition of the hair cycle from the resting phase (telogen) to the growth phase (anagen), promoting hair regrowth within 7 days. The study concluded that the microneedle device significantly improved hair regrowth with biocompatibility, making it a potential candidate for minimally invasive hair loss treatment.