Detachable Microneedles via Host-Guest Supramolecular Polymer Networks

Point-of-use devices to conveniently deliver proteintherapeuticsare of growing need. Microneedles offer an approach to deliver biopharmaceuticalsacross the skin and circumvent syringe-based injection or harsh oralenvironments. Certain microneedles rapidly dissolve to deliver theirpayload, while others affix to the skin for sustained release. Here,a microneedle platform combining a PEG-based supramolecular polymernetwork with a mechanical biopolymer network is able to penetratethe skin, where the microneedles subsequently swell; those composedof supramolecular cross-links detach upon device removal. The embeddedsupramolecular microneedles afford sustained delivery of insulin for>12 h of blood glucose correction following only 5 min of skinapplication.Conversion of the supramolecular cross-links to a covalent form preventsmicroneedle detachment, with brief application failing to correctblood glucose. This approach offers a simple route of fabricatingdetachable microneedles using polymer formulations with supramolecularbonding, improving on the complex fabrication of previous detachablemicroneedle designs.