Detachable Microneedles via Host–Guest Supramolecular Polymer Networks

Point-of-use devices to conveniently deliver protein therapeutics are of growing need. Microneedles offer an approach to deliver biopharmaceuticals across the skin and circumvent syringe-based injection or harsh oral environments. Certain microneedles rapidly dissolve to deliver their payload, while others affix to the skin for sustained release. Here, a microneedle platform combining a PEG-based supramolecular polymer network with a mechanical biopolymer network is able to penetrate the skin, where the microneedles subsequently swell; those composed of supramolecular cross-links detach upon device removal. The embedded supramolecular microneedles afford sustained delivery of insulin for >12 h of blood glucose correction following only 5 min of skin application. Conversion of the supramolecular cross-links to a covalent form prevents microneedle detachment, with brief application failing to correct blood glucose. This approach offers a simple route of fabricating detachable microneedles using polymer formulations with supramolecular bonding, improving on the complex fabrication of previous detachable microneedle designs.