Stable Nanoparticles Prepared by Heating Electrostatic Complexes of Whey Protein Isolate–Dextran Conjugate and Chondroitin Sulfate

Abstract

A simple and green method was developed for preparing the stable biopolymer nanoparticles with pH and salt resistance. The method involved the macromolecular crowding Maillard process and heat-induced gelation process. The conjugates of whey protein isolate (WPI) and dextran were produced by Maillard reaction. The nanoparticles were fabricated by heating electrostatic complexes of WPI-dextran conjugate and chondroitin sulfate (ChS) above the denaturation temperature and near the isoelectric point of WPI. Then, the nanoparticles were characterized by spectrophotometry, dynamic laser scattering, zeta potential, transmission electron microscopy, atomic force microscopy, and scanning electron microscopy. Results showed that the nanoparticles were stable in the pH range from 1.0 to 8.0 and in the presence of high salt concentration of 200 mM NaCl. WPI-dextran conjugate, WPI, and ChS were assembled into the nanoparticles with dextran conjugated to WPI/ChS shell and WPI/ChS core. The repulsive steric interactions, from both dextran covalently conjugated to WPI and ChS electrostatically interacted with WPI, were the major formation mechanism of the stable nanoparticles. As a nutrient model, lutein could be effectively encapsulated into the nanoparticles. Additionally, the nanoparticles exhibited a spherical shape and homogeneous size distribution regardless of lutein loading. The results suggested that the stable nanoparticles from proteins and strong polyelectrolyte polysaccharides would be used as a promising target delivery system for hydrophobic nutrients and drugs at physiological pH and salt conditions.

Different Strategies for the Preparation of Galactose-Functionalized Thermo-Responsive Nanogels with Potential as Smart Drug Delivery Systems

“…The results indicate that the hydrophilic chains containing GAL and PEGMA stabilize the nanogels in aqueous solution at room temperature. Similar results, where the zeta potential decreases to negative values while the pH increases, have been observed also in nanometric systems with other oligosaccharides [ 55 , 56 , 57 ]. The fact that these nanogels are anionic at physiological pH may be advantageous for its application in drug delivery systems since a cationic charge at pH 7.4 is usually related to cytotoxicity toward cell-lines [ 58 ].…”

Effects of amidated low methoxyl pectin on physiochemical and structural properties of polymerized whey proteins

“…Figure 1 shows the effects of ALM pectin (0.3%) on mean particle size of polymerized WPs prepared at different heating times. Polymerized WPs showed diameters in the range of 40-80 nm, which was consistent with the results reported by Dai et al (2015) and Silva et al (2010). No significant difference in particle size was found among all polymerized WP samples, p > 0.05.…”

The use of nano-sized eggshell powder for calcium fortification of cow?s and buffalo?s milk yogurts

“…The zeta-potential (ζ-potential) of nano-ESP was determined by laser Doppler electrophoresis at 25°C using a Malvern Zetasizer Nano ZS analyzer (Malvern Instruments Ltd., Malvern, UK). Each five-times diluted sample (1 ml) was transferred to a universal folded capillary cell equipped with platinum electrodes, and ζ-potential was determined by measuring the direction and velocity of the nanoparticles moving in the electric field and then calculated by the Zetasizer Software (Malvern Instruments Ltd., Malvern, UK) according to the Henry equation as given by (Dai et al, 2015).…”