Next-generation epidermal patches: Bridging 3D and multidimensional printing for biomedical and personal care...

Advances in additive manufacturing, particularly 3D and multidimensional printing, have enabled unprecedented control over the architecture, composition, and bioactivity of epidermal patches. These developments have broadened the scope of epidermal patches across biomedical and personal-care applications, supporting personalized and adaptive solutions for drug delivery, wound management, tissue regeneration, and skin-related interventions. This review summarizes next-generation printed epidermal patches, covering both conventional (non-microneedle) systems and microneedle-integrated platforms. Particular emphasis is placed on emerging material systems, including self-oxygenating hydrogels, nanomaterial-free bioinks derived from proteins and polysaccharides, and functional nanocomposite formulations. We examine key 3D printing strategies for fabricating acellular constructs, cell-laden matrices, and microneedle array patches (MAPs), alongside recent advances in multidimensional printing technologies. Biomedical applications are discussed with a focus on dermal and transdermal drug delivery, particularly insulin delivery for diabetes management as well as wound repair, regenerative therapies, photodynamic treatments, and biosensing. Additionally, the integration of printed epidermal patches with wearable sensors, smart devices, and artificial intelligence (AI) is highlighted as an emerging frontier in intelligent skin-interfaced systems, with implications for both healthcare and advanced personal-care technologies. Finally, key challenges related to clinical translation, regulatory pathways, and commercialization are addressed, providing strategic insights to guide the advancement of hydrogel-based additive manufacturing from laboratory innovation to real-world clinical and aesthetic applications.