Engineered rice plants as safe peptide drug synthesis and delivery system

The UNIPI team developed an innovative, safe and efficient drug delivery system based on plant biotechnologies (genetic engineering of rice plants). By means of this system, therapeutic peptides are synthesized within the rice seeds (used as a ‘bioreactor’) and then delivered to the disordered organism via oral administration of the therapeutic rice, without any need for purification, being the rice a well-tolerated and known food. In a proof-of-concept study, the UNIPI team demonstrated the safe and efficient delivery of Apolipoprotein A-I Milano (AIM) via this system to atherosclerotic mouse models. The AIM protein retained its anti-atherogenic and anti-inflammatory properties and allowed both atherosclerotic plaque reduction and hepatic inflammation to decrease as compared to the placebo-treated group, even if the mice were still exposed to dyslipidemic diet (PMID:29907443). This prototype-level rice can be scaled-up as an innovative functional food.

The experimental plan will be structured with the following objectives:

• Evaluation of intestinal transit and absorption of AIM. Lyophilized APO-rice seeds will be processed to mimic gastrointestinal digestion (INFOGEST protocol) and incubated, at defined dosages, with intestine-on-chip platform to measure transepithelial electrical resistance (TEER) and to detect AIM protein (ELISA, immunofluorescence).
• Evaluation of the anti-inflammatory effects of AIM in the inflamed intestine-on-chip platform. Intestine-on-chip will be exposed to pro-inflammatory stimuli (DSS) and then incubated with APO-rice at defined dosages. Inflammatory markers will be analyzed.
• Evaluation of antioxidant properties of APO-rice. APO-rice will be incubated with human cell lines and/or ex-vivo isolated organs to evaluate the healthy properties on the cardio-metabolic system (e.g. cell viability, ROS and cytokines levels, vascular dysfunction).

• Demonstration, in a reliable and advanced human in vitro intestinal system, the intestinal absorption of AIM after gastric digestion of the APO-rice, a fundamental feature of such prototype for scaling up.
• Definition of the amount of AIM passing the intestinal barrier.
• Molecular characterization of the anti-inflammatory and antioxidant effects of AIM in the intestine-on-chip and in other cell types.
• Evaluation of the cardiometabolic healthy properties on ex-vivo isolated organs (e.g. evaluation of vascular functionality).