Effect of Double Bond in Unsaturated Long-Chain Monoglyceride in Self-emulsified Nanoemulsion on Tight Junction Opening

Abstract Unsaturated long chain monoglycerides (LCMs) used to formulate self-emulsified nanoemulsion (SEN) are varied in their degree of unsaturation which may influence their activities on membrane permeability. Therefore, this study highlights the impact of double bond in LCMs on the tight junctions of Madin-Darby Canine Kidney (MDCK) cell monolayer. Two LCMs, Glyceryl monooleate (one double bond) and Glyceryl monolinoleate (two double bonds) were formulated into SENs (SEN2 and SEN3, respectively) with Glyceryl tricaprylate and PEG-40 hydrogenated castor oil (1:1:2), and compared to the SEN (SEN1) consisted of only Glyceryl tricaprylate and PEG-40 hydrogenated castor oil (1:4). Lucifer Yellow (LY, MW 457) or Fluorescein isothiocyanate–Dextran4K (FD4, MW 3000-5000) was added to the aqueous phase of the SENs and tested for their transport across the cell monolayer. The cumulative transport of LY and FD4 achieved by SEN2 and SEN3 were significantly (p