Type 2 diabetes mellitus (T2DM) is characterized by progressive hyperglycemia, peripheral insulin resistance, and
β-cell dysfunction. It is a chronic disease that is one of the leading causes of high mortality and morbidity rates.
Therefore, the development of drugs that lower blood glucose levels in T2DM patients is crucial. Glucagon-like
peptide-1 (GLP-1) receptor agonists are increasingly being used in clinical practice for the management of type 2
diabetes mellitus. The potent glucagon-like peptide 1 (GLP-1), a natural small incretin hormone, enhances insulin
secretion in a glucose-dependent manner. However, the extremely short half-life of GLP-1 and the need for its
subcutaneous administration limit its clinical application. Thus, half-life extension and alternative delivery
methods are highly desired. DARPin domains with a high affinity for human serum albumin (HSA) have been
selected for the half-life extension of therapeutic peptides and proteins. In our previous study, we designed trivalent
fusion proteins as oral candidates for long-acting GLP-1R agonists by genetically fusing a protease-resistant
modified GLP-1, HSA-binding DARPin, and a Penetratin cell-penetrating peptide. The aim of this study was to
develop a bioprocess for the production of long-lasting GLP-1 in tobacco chloroplasts as GLP-1reseptor agonist
with potential for oral delivery in a bioencapsulated form in plant cells for the treatment of type 2 diabetes mellitus