Versatile Platforms of Microneedle Patches Loaded with Responsive Nanoparticles: Synthesis and Promising Biomedical Applications

Microneedle array systems loaded with responsive nanoparticles have received increasing attention due to the advantages of good drug stability, targeting ability, controlled release of drugs, high bioavailability, painlessness, and good patient compliance. Compared with oral drug delivery, microneedle transdermal drug delivery eliminates the need to pass through the gastrointestinal tract and liver, reducing the metabolic consumption of drugs by first-pass effect. While compared with intravenous drug delivery, microneedle transdermal drug delivery reduces patient discomfort and does not require professional administration. However, there are few review articles on microneedles loaded with responsive nanoparticles. Herein, the current researches on microneedles loaded with specific responsive nanoparticles such as glucose-responsive, pH-responsive, enzyme-responsive, light-responsive, magnetic-responsive, ultrasound-responsive, and multiresponsive, and the biomedical application of these microneedle array systems are summarized. In addition, the challenges and prospects of microneedle strategies loaded with responsive nanoparticles are briefly discussed, which will facilitate the development of such versatile drug-delivery strategy.