Optimized layered microneedle design for precise transdermal drug delivery: Overcoming skin elasticity Challenges

Microneedle-based transdermal drug delivery has shown great potential for effective medication, yet traditional microneedle designs encounter difficulties in overcoming skin elasticity, often leading to incomplete penetration and inaccurate drug delivery. In this study, we engineered a unique layered microneedle (LMNs) structure based on material properties to address these limitations. In vitro tests confirmed the LMNs possess excellent mechanical strength and moisture resistance. Puncture and hypoglycemic experiments in mice demonstrated that compared with the insulin injection group, where blood glucose drops rapidly to 20% of the baseline, the insulin-loaded LMNs group shows a gentler blood glucose regulation, with a 25% decrease at 35 min followed by a gradual rebound. The LMNs’ design effectively surmount the limitations of skin elasticity, with the drug-carrying part fully inserted into the skin, enabling precise control of the drug dosage at the target site and enhancing overall drug delivery precision. Overall, LMNs exhibit distinct advantages in precise drug delivery and have broad application prospects in transdermal drug delivery and various clinical treatment scenarios.