Diabetes and obesity have emerged as major global health concerns. Glucagon-like peptide-1 (GLP-1), a natural incretin hormone, stimulates insulin production and suppresses glucagon secretion to stabilize and reduce blood glucose levels and control appetite. The therapeutic use of GLP-1 receptor agonists (e.g., semaglutide) has transformed the standard of care in recent years for treating type 2 diabetes and reversing obesity. The native GLP-1 sequence has a very short half-life, and therapeutic advances have come from molecular engineering to alter the pharmacokinetic profile of synthetic GLP-1 receptor agonists to enable once-weekly administration, reduce the frequency of injection, and improve adherence. Efforts to further extend this profile would offer additional convenience or enable entirely different treatment modalities. Here, an injectable GLP-1 receptor agonist depot is engineered through integration of a prosthetic self-assembling peptide motif to enable supramolecular nanofiber formation and hydrogelation. This supramolecular GLP-1 receptor agonistic (PA-GLP1) offers sustained release in vitro for multiple weeks, supporting long-lasting therapy. Moreover, in a rat model of type 2 diabetes, a single injection of the supramolecular PA-GLP1 formulation achieved sustained serum concentrations for at least 40 days, with an overall reduction in blood glucose levels and reduced weight gain, comparing favorably to daily injections of semaglutide. The general and modular approach is also extensible to other next-generation peptide therapies. Accordingly, the formation of supramolecular nanofiber depots offers a more convenient and long-lasting therapeutic option to manage diabetes and treat metabolic disorders.
Keywords: drug delivery; hydrogels; nanotechnology; self-assembly; supramolecular chemistry.