Isolation and In Vitro Stability Studies of Edible Plant-Seed Derived (Raphani Semen) Nanoparticles

Abstract

(1) Background: Edible plant-derived nanoparticles contain large amounts of endogenous substances and can be used as carriers for disease treatment. However, the extraction rate and purity are not high. Raphani Semen, the dried seed of the Raphanus sativus L., has been used as food and medicine for clinical treatment and health care for many years. (2) Methods: This study began with the extraction of edible Raphani Semen-derived nanoparticles (ERDNs) by ultracentrifugation (UC). Then a new method was proposed for ERDNs to be extracted by polyethylene glycol (PEG) and purified by size exclusion chromatography (SEC), followed by SDS-PAGE for identified proteins. The stability of ERDNs was also verified in three digestion simulations. (3) Results: The PEG offered higher yields of 1.14–2.31 mg/g than UC. Transmission electron microscopy showed both UC and PEG with cup-shaped nanoparticles of around 200 nm. The SEC-purified ERDNs contained a range of proteins smaller than 70 kDa. The size stability of ERDNs in digestion solutions demonstrated their ability to withstand extreme conditions, confirming their potential as a nano drug delivery platform. (4) Conclusions: In conclusion, the data suggest that PEG+SEC could isolate ERDNs with high efficiency, providing a reference for the separation of other seed nanoparticles.