In the first part of the project, we have exploited our dual-action strategy towards improved GLP-1 delivery in the context of type 2 diabetes mellitus treatment. First, we developed a lipid-based nanocapsule that could induce GLP-1 secretion both in vitro and in vivo per se, without the addition of any supplementary peptide. Then, we included within our nanocarrier exenatide, a GLP-1 analog with a short half-life of 2.5 h. We evaluated in vivo in acute and chronic murine models of the disease the pharmacological effect of our formulation, comparing the effect of our oral strategy with the marketed subcutaneous injection. We observed that exenatide-loaded lipid nanocarriers-treated mice exhibited normalised plasma glucose levels comparable to those of untreated control mice, along with decreased insulin levels. We have demonstrated that our approach led to comparable results regarding glucose homeostasis to those observed for the current marketed drug that is administered subcutaneously. The non-inferiority of our approach together with the benefit of administration by the oral route for chronic treatments was highlighted. We further demonstrated that by tailoring the surface of the nanocarriers, we could increase GLP-1 secretion leading to a less frequent administration of the formulation rendering the same pharmacological effect. Thus, we can tailor the surface of these nanocarriers in order to provide with improved peptide stimulation in vivo. We further conducted mechanistic studies in mouse and human knock-in and knockout intestinal organoids and show that agents used as commercial lipid excipients can activate nutrient-sensitive receptors on enteroendocrine cells (EECs) and, when formulated as lipid nanocarriers, can bestow biological effects through the release of GLP-1, GIP, and PYY from K and L cells. Studies in wild-type, dysglycemic, and gut Gcg knockout mice demonstrated that the effect exerted by lipid nanocarriers could be modulated by varying the excipient (e.g. nature and quantities), the formulation methodology, and their physiochemical properties (e.g. size and composition). We demonstrated the therapeutic potential of using nanotechnology to modulate release of multiple endogenous hormones from the enteroendocrine system through a patient-friendly, inexpensive, and noninvasive manner. In the context of inflammatory bowel disease treatment, we confirmed the ability of the formulation to induce GLP-2 secretion and induce mucosal healing in acute and chronic murine models of the disease. We have conducted studies to evaluate the effect of the formulation on gut microbiota composition and the impact on the therapeutic efficacy of our formulation, with the analysis currently ongoing. The results from this project have been published in Gut, Biomaterials, Bioactive Materials or Science Advances, they have been presented in scientific conferences and the strategy has been patented.
