Molecular pathogenesis of acne and their microneedle treatments

• Acne is a chronic inflammatory skin disorder driven by genetics, hormones, immune dysregulation, follicular hyperkeratosis, and C. acnes proliferation. • Microneedle-based therapies provide innovative drug delivery strategies that enhance efficacy and minimize side effects in acne treatment. • Further optimization of microneedle design and clinical translation is required to fully realize their therapeutic potential. Acne vulgaris is a chronic inflammatory disorder of the pilosebaceous unit, which brings serious physical and mental burden to patients. Despite decades of research, its pathogenesis remains multifactorial and incompletely elucidated. Conventional therapeutic approaches still have limitations in meeting clinical demands due to limited skin penetration, systemic side effects, and the emergence of antimicrobial resistance. Microneedles based drug delivery systems offer a minimally invasive strategy to overcome the stratum corneum barrier, achieve controlled intradermal drug release, and enhance local therapeutic efficacy while reducing systemic toxicity. This review systematically summarizes the latest research of microneedles for the treatment of acne. We first introduce the pathological mechanisms underlying acne development, followed by an overview of the latest advances in microneedle technologies for targeted acne therapy, including dissolving, hydrogel, solid, hollow, coated microneedles and stimuli-responsive designs. Finally, we highlight ongoing limitations and propose future strategies to enhance the development and clinical application of microneedle therapies in acne management.