Microneedle-mediated therapies in hair loss: applications, mechanisms, and future directions

Microneedles, as minimally invasive tools for percutaneous delivery, have undergone significant technological advancements over the past decade, greatly expanding their application in the treatment of hair loss. Traditional microneedle devices promote hair regrowth by stimulating vascularization and the release of growth factors through controlled skin disruption. In addition, microneedle-mediated drug delivery enhances local drug penetration and absorption, thereby regulating the hair growth cycle more effectively. During hair transplantation procedures, microneedle-assisted techniques can notably improve follicle survival rates due to their precision and advanced design. For individuals with baldness, tissue-engineered hair follicle regeneration offers an innovative and effective strategy to increase the total number of hair follicles. However, these engineered follicles often face challenges, such as difficulty in emerging through the skin and growing in excessively dense or disorganized patterns. Integrating microneedle arrays with tissue engineering approaches may help address these issues by enabling better control over the direction and density of regenerated hair. This article reviews the historical development of microneedles, examines their current applications in hair loss therapy, and discusses ongoing challenges in the field. The goal is to explore the therapeutic potential of microneedles in hair regeneration and to offer insights that may guide future treatment strategies.