Going Below and Beyond the Surface: Microneedle Structure, Materials, Drugs, Fabrication, and Applications for Wound Healing and Tissue Regeneration

Microneedles offer significant advantages for wound healing and tissue regeneration by penetrating physical barriers, providing mechanical stimulation, and overcoming drug resistance. They can deliver a wide range of drugs, including small and large molecules, nucleic acids, nanoparticles, and cells. Various materials like metals, silicon, ceramics, and polymers are used in their fabrication, each with unique properties. Advanced designs allow for controlled drug release, and fabrication techniques include MEMS-based methods, micromolding, drawing-based methods, and 3D printing. Studies show microneedles improve wound healing in diabetic rat models and treat conditions like hypertrophic scars, myocardial infarction, osteoarthritis, and hair regrowth. Future research should focus on optimizing designs and integrating new functionalities to enhance clinical applications.