Preparation of chitosan/gum Arabic nanoparticles and their use as novel stabilizers in oil/water Pickering emulsions

Abstract

A B S T R A C TRecently, there has been a renewed interest in Pickering emulsions owing to their surfactant-free nature, and the use of natural-based particles as stabilizers became a priority due to the applications they can enable. In this work, chitosan/gum Arabic (CH/GA) nanoparticles were synthesized and tested as novel stabilizers. Among the tested CH/GA weight ratios, the particles prepared using 1:1 ratio exhibited near-neutral wettability, an average size of 108.6 nm and a zeta potential of 56.3 mv. Pickering emulsions prepared from these particle dispersions (1.5% w/v), and high oil volume fractions (φ = 0.6, 0.7), have shown high storage stability. Moreover, confocal laser scanning microscopy confirmed the o/w type and the effective adsorption of the nanoparticles at the oil/ water interface forming a barrier against droplets coalescence. The emulsions have shown shear-thinning and elastic-like behavior. These findings open new avenues for using these emulsions as novel delivery systems, e.g. in cosmetic and food applications.

Enhancing trans-resveratrol topical delivery and photostability through entrapment in chitosan/gum Arabic Pickering emulsions

“…These values are in agreement with what was observed previously by optical microscopy, which pointed out for a minor coalescence of the droplets with time. Moreover, the values follow the pattern of our previous study concerning the development of the base Pickering emulsions (prepared without RSV) [23]. These base formulations maintained their stability for the studied period of two months.…”

“…The obtained size distribution in number of the produced CH/GA nanoparticles (1.5% w/v) is characterized by an average size of 109 nm, and a polydispersity index (PDI) of 0.218. Previous studies on this system indicated that only minor agglomeration occurred during storage [23].…”

“…2) show that the developed CH/GA nanoparticles are spherical, semi-spherical and oval. The irregular morphology of the nanoparticles is due to the absence of an oil core template for the deposition of the CH/GA coacervates [23].…”

“…The nanoparticles were prepared through ionotropic gelation following a method developed in our research group [23]. Briefly, CH/GA nanoparticles (with 1:1 weight ratio) were prepared at two different concentrations, namely 0.5% and 1.5% w/v.…”

“…In a recent study, our research group developed biopolymeric chitosan/gum Arabic nanoparticles with near-neutral wettability and successfully used these nanoparticles to produce novel biodegradable o/w Pickering emulsions, which have presented high storage stability and excellent rheological properties for cosmetic applications [23]. Following these advancements, the main objective of the present work is to investigate the potential use of Pickering emulsions stabilized with chitosan/ gum Arabic nanoparticles as novel surfactant-free delivery vehicles for the topical application of trans-resveratrol.…”