Systhesis And Bioactivity Study Of Zein-anion Polysaccharide Core/Shell Anoparticle Delivery Systems Loaded With Curcumin

Nano-delivery system has been getting more and more attention in food industry and drug targeted delivery areas.It would make an increasing uptake rate in vovo,since the application of biopolymers(e.g. protien) as food/drug delivery material for control release and targeted delivery has been used.Proteinshave various advantages such as wildly avalable,high loading efficiency easily complexing with cetain food/drug via its polar and nonpolar bonds, and have attracted the attention of researchers in developing nano delivery sysytems.Zein is generally regarded as safe(GRAS) as food material and is amphiphilic as it has more than 50% amino acid residues which make it soluble in 50%~95% ethanol and make it a widly used as hydrophobic food/drug delivery system. In present study,curcumin loaded zein nanoparticles were synthetized with anti-solvent method, and the particles were further coated with pectin by electrostatic deposition to form zein core/pectin shell nanoparticles. The effects of pectin concentrations and pH changes on nanoparticle suspension stability were investigated.We also investigate its antioxidant capacity, antibacterial capacity and simulated gastrointestinal absorption efficiency. The main results are as following:1. Curcumin loaded zein nanoparticles were synthetized with anti-solvent method, and the particles were further coated with pectin by electrostatic deposition to form zein core/pectin shell nanoparticles. The effects of pectin concentrations and pH changes on nanoparticle suspension stability were investigated. The long term storage stability of particle suspension and the antioxidant activity of loaded curcumin were also determined. The results showed that stable nanoparticles formed when the pectin concentration in colloid suspension was 0.11%; The nanoparticles were very stable at acid and neutral pH with the average particle size lower than 250 nm, but increased to higher than 300 nm at pH 6.0~6.5; The particle suspension was very stable after 1 month storage at room temperature.2. Zein-pectin core/shell nanoaprticlesloaded with curcumin have poor stabilities from aggregation at neutral pH or NaCl existence.3. The nanoparticles, which prepared by replacing 30% pectin with alginate, exhibit superior stability at pH4~7 with the size ranged from about 130 nm to 220 nm; these particles were also stable at pH 5 even the NaCl concentration higher up to 300 mM with the average diameter lower than 200 nm.4. The encapsulated Curcumin in nanoparticles(1.44±0.03 mg Troloxequivalent) exhibited strong antioxidant activity and the total antioxidant capacity was two times higher than that of free curcumin solubilized in ethanol(0.78±0.03 mg Troloxequivalent). These nanoparticles have superior DPPH Scavenging activity and Fe(Ⅲ) reducing capacity when compared with curcumin-ethanol solution(P<0.05).5. Curcumin-loaded zein-pectin/alginate sphere in redispertitive solution representedmuch poorer antimicrobial activity than curcumin-DMSO solution,due to its poor diffusioninto agar medium.6. The digestion and absorbability of curcumin-loaded zein-pectin nanoparticlesis three times higher(14.8%) than that of curcumin, zein and pectin mixture(3.6%). Curcumin-loaded a poorer antimicrobial activity than curcumin-DMSO solution as its size has exceeded nanoscale.