Funding: Supported in part by UID/DTP/04138/2019 from FCT, Portugal and DREAMS (ULHT). SEM analysis was funded by FCT/MCTES for the financial support to CESAM (UIDP/50017/2020+UIDB/50017/2020), through national funds.; Currently, insulin can only be administered through the subcutaneous route. Due to the flaws associated with this route, it is of interest to orally deliver this drug. However, insulin delivered ...