Study On Pickering Emulsion Stabilized By Curcumin Nanocomplexes

Curcumin is a kind of polyphenol and high-dose oral administration is safe and effective,which has many bioactivities,such as anti-oxidation,anti-tumor,anti-inflammatory and other pharmacological properties;Curcumin known for its low bioavailability,poor water-solubility,thermal and pH photostability limit its application.In this study,the interaction between gelatin and curcumin was used to form a nanocomplexes,and then combined with polysaccharide to form colloidal particles,which were used as stabilizers to prepare Pickering emulsion,the bioavailability of curcumin and the oil oxidation stability of emulsion were systematically studied.The results are as follows:（1）In this study,the curcumin nanocomplexes was prepared by self-assembly method and the solubility of curcumin was improved,the nanocomplexes characterized by morphology,size,surface charge and hydrophobicity;The surface hydrophobicity of gelatin was studied by fluorescence probe method;The interaction between gelatin and curcumin was studied by spectroscopic method;The formation mechanism of the nanocomplex was further analyzed by infrared technique;Analyze the presence of curcumin in the complex by differential scanning calorimetry;The stability and in vitro release of curcumin in simulated gastrointestinal pH environment,light,uv and high temperature were studied;The free radical scavenging ability of the curcumin nanocomplexes was investigated.The experimental results show that the curcumin nanocomplexes is an irregular nanoparticle with a particle size of 117.2±3.6 nm and a potential of12.2±2.8 mV.The drug loading increases with the increase of curcumin concentration.The water solubility of curcumin in the complex significantly increased than original drug;There is hydrophobic and hydrogen bonding between gelatin and curcumin in the nanocomplex,and the curcumin exists in amorphous form in the nanocomplexes;Curcumin nanocomplexes solution can efficiently protect curcumin from UV-light,pH,light and high temperature transformation and the degradation rate of curcumin was significantly reduced,The chemical stability showed that stability of curcumin was significantly improved than free curcumin;In vitro release of the nanocomplex exhibited that the release content of curcumin significantly increased than the free curcumin;The antioxidant capacity of curcumin in the nanocomplex was obviously increased.（2）Carrageenan（CG）,konjac（KGM）,chitosan（CH）and the curcumin nanocomplexes prepared above were further compounded to obtain composite colloidal particles loaded with curcumin.Turbidity and potential changes of different ratios of GB-CG,GB-KGM and GB-CH under different pH conditions were systematically studied to determine the optimal polymerization ratio.The chemical stability,antioxidant activity,simulated gastrointestinal digestion and release characteristics of curcumin in colloidal particles were studied.The experimental results showed that the optimal polymerization ratio of GB-CG,GB-KGM and GB-CH was 2:1,and the optimal polymerization pH was 3.0,4.5,5.5.The addition of polysaccharides can enhance the hydrophobic effect between gelatin and curcumin,the chemical stability and antioxidant capacity of curcumin in colloidal particles were obviously improved.Higher curcumin bioaccessibility in the complexes after digestion indicated that colloidal complexes can efficiently increase curcumin stability during gastrointestinal digestion.（3）Formation of Pickering emulsion stabilized by three types of structure of colloidal nanoparticles,different oil phases（φ）,different gelatin concentrations（C）,gelatin-polysaccharide ratio（r）were mainly studied.To explore the physical chemistry and storage stability of emulsion;Interfacial layer surrounding the lipid droplets in an oil-in-water emulsion was studied on its oxidative stability;Effects of emulsions on the bioaccessibility of curcumin and the oxidative stability of oil were studied using a simulated gastrointestinal tract.The experimental results exhibited that the optimum conditions of the emulsion were oil ratio φ=40%,gelatin concentration C=10mg/ml,gelatin/polysaccharide ratio r=2:1;The rate of primary oxidation products（POV）and secondary oxidation products（MDA）were significantly inhibited in the process of accelerating the experiment;Colloidal complexes were incorporated into emulsion to evaluate antioxidant activity and GB-KGM colloidal has the best inhibiting effect on oil oxidation;The hydrolysis degree of Pickering emulsion was significantly lower than that of pure corn oil,at the same time,the bioaccessibility of curcumin was obviously improved.The accumulation of positively charged emulsion,thicker interfacial layer and interfacial antioxidants slowed down the oxidation rate of oil in the process of digestion.（4）The concentration of curcumin in plasma was determined by HPLC,and the pharmacokinetics of curcumin suspension,curcumin nanocomplexes,GB-KGM complex colloidal particles,GB-cur-E,GB-cur-KGM-E were studied,the peak concentration of blood drug and extended of curcumin nanocomposite and GB-KGM composite colloidal particles increased compared with curcumin suspension,the C_max of GB-cur-KGM-E was further increased,the average residence time MRT0-∞of curcumin in vivo was prolonged,and the oral bioavailability of curcumin was improved.