Glepaglutide as a promising mucosal healer for inflammatory bowel disease treatment via foam delivery

Details

Supervisors

Beloqui Garcia, Ana ; Dupont-Gillain, Christine C.

Faculty

Faculté des bioingénieurs

Degree label

Master [120] : bioingénieur en chimie et bioindustries, à finalité spécialisée

Abstract

Inflammatory bowel disease (IBD) is a group of chronic inflammatory conditions of the gastrointestinal tract characterized by two major subcategories which are Crohn’s disease (CD) and ulcerative colitis (UC). Crohn’s disease (CD) can affect any portion of the gastrointestinal tract with several areas of inflammation whereas ulcerative colitis (UC) consists of a continuous localized area of inflammation starting from the distal part of the colon until the rectum with no appearing signs of normal tissue in between the inflamed portions. Several anti-inflammatory drugs, such as Mesalazine (5-aminosalicylic acid), corticosteroids, and immunosuppressant drugs, are already widely purchased in the market. Those drugs are typically administered orally, even though other forms are also possible, and their dosage depends on the specific drug and condition being treated. However, to this day, no anti-inflammatory drug works as a mucosal healer. Therefore, interest has recently increased in the research field toward glucagon-like peptide 2 (GLP-2) analogs. Those are highly discussed as they are considered good alternatives to conventional anti-inflammatory drugs for their therapeutic potential in gastrointestinal disorders. One of those analogs is called glepaglutide; a 33 amino-acids long peptide sharing a similar sequence to the sequence of glucagon-like peptide 2 (GLP-2) with 24 amino-acids out of the 33 amino-acids complete chain. This project aims to develop a foam and gas both loaded with glepaglutide to deliver this macromolecule in the colon using carbon dioxide (CO2) as a permeation enhancer. The foam formulation was based on a gas sauce and additional foaming reagent components. The gas sauce consisted in a basic solution of potassium bicarbonate (PB) and an acidic solution of citric acid (CA). The basic solution was used as the stock solution for the macromolecule while the acidic solution was used as a foaming reagent. The additional foaming reagents were added to the latter solution. The gas formulation consisted of the gas sauce mentioned for the foam formulation, without adding any additional foaming reagent components. Glepaglutide concentrations were notably assessed through HPLC analysis and showed to remain stable both in the foam and gas formulations. The stability of this peptide was also evaluated through time in its basic stock solution via repeated high-performance liquid chromatography (HPLC) and intrinsic fluorescence analysis. Glepaglutide was shown to be stable through time as well. Eventually, in vivo studies were performed on mice with colitis induced with three percent dextran sulfate sodium (DSS) to test the efficacy of glepaglutide. Those mice were separated into seven different groups, of which each of them received a different type of therapy following DSS treatment. Mice were weighed every day. Distal and proximal colon cytokines levels and MPO activity were assessed. Those molecules provide substantial information on the degree of inflammation. Plasma citrulline concentrations and mRNA gene expression of MUC2, ZO-1, and occludin proteins were also evaluated. Those components are mucosal healing markers and are thus particularly relevant for the efficacy evaluation of inflammatory bowel disease (IBD) treatment.