Carrier Polymer-Free Dissolvable Microneedles Enable\nSuperhigh Drug Payload for Percutaneous Protein Delivery

Microneedle (MN)\npatches present a painless alternative for transdermal\ndelivery of monoclonal antibodies (mAbs), yet existing dissolvable\nMNs are hindered by a low drug-loading capacity (DLC). This study\nintroduces a carrier-free approach for fabricating mAb MNs by a solution-casting\nmethod, providing a superhigh drug-payload MN platform (DLC around\n70%). Additionally, the use of concentrated proteins prevents interpenetration\nbetween the backing layer and the tip, assuring the dosage accuracy\nof the therapeutic antibodies. Physicochemical characteristics, including\nmechanical strength, dissolvability, and skin permeability, were evaluated\nand compared with conventional PVP K17 (poly(vinylpyrrolidone), K17)\nmicroneedles. Finally, the transdermal performance of protein dMNs\nwas assessed using IL-17A (Iinterleukin-17A) antibody as a model protein\ndrug, with in vivo therapeutic efficacy evaluated in a psoriatic mouse\nmodel. The results demonstrate the feasibility and effectiveness of\nexcipient-free dMNs for mAb delivery, significantly improving the\ndrug-loading capacity, while mitigating safety concerns associated\nwith carrier polymers.