Self-assembly, functionality, and in-vitro properties of quercetin loaded nanoparticles based on shellac-almond gum biological macromolecules

Quercetin-fortified nanoparticles were prepared from almond gum (AG), a novel biological macromolecule, and Tween 80 (T80) as stabilizers and shellac (SH) as core material using an antisolvent precipitation method. The final nanoparticles were prepared by 0.67% SH, 0.02% Q, 0.5% AG and 0.1% w/v T80 using the stirring speed of 750 rpm at a dosing rate of 0.5 ml/min. The morphology of the particles was characterized using Cryo-SEM and TEM microscopy. The average particle size was 135 ± 8 nm with a polydispersity index of 0.252 ± 0.01 and an encapsulation efficiency of 97.7 ± 1.2%. At pH 7.4 (intestinal pH), quercetin-loaded nanoparticles showed significantly (p < 0.05) higher antioxidant activity compared to free quercetin while the degradation of quercetin was lower in the nanoparticles compared to free quercetin at the similar pH. Quercetin loaded in nanoparticles was successfully found to be 2 times more available for uptake than free quercetin at pH 7.4. MTT and SRB assays revealed that no significant (p > 0.05) toxicity was observed for Caco-2 cells treated with quercetin-loaded nanoparticles with a dilution factor of 100. This study provides information about the formulation of promising nanocarriers using biological macromolecules for oral delivery of bioactive compounds.