蛋白水解物及多糖负载姜黄素制备纳米颗粒及其稳定性

Preparation of curcumin nanoparticles by protein hydrolysates and polysaccharids and its stabilization

为了提供一种姜黄素纳米颗粒的制备载体,该文以玉米醇溶蛋白水解物(zein hydrolyate,ZH)和大豆可溶性多糖(soluble soybean polysaccharides,SSPS)复合物(ZH-SSPS)为原料,通过反溶剂纳米沉淀法制备了一种水溶性姜黄素纳米颗粒(curcumin nanoparticles,Cur-Ps),并考查了SSPS与ZH在制备姜黄素纳米颗粒中的协同作用。研究结果表明,当ZH的质量浓度在2.5 mg/m L以下时,SPSS的存在会使姜黄素的水溶性有所提高。当ZH的质量浓度在2.5 mg/m L以上时,姜黄素在水中的溶解量可高达135μg/m L,SSPS的加入无法使姜黄素的水溶性进一步提升。在中性条件(p H值7.0)或低离子强度(<50 mmol/L)下,ZH及ZH-SSPS分别制备的姜黄素纳米颗粒(Cur-Ps)都具有良好的胶体稳定性。但在酸性(p H值为4.5和2.0)或高离子强度(>200 mmol/L)下,ZH-SSPS较单独的ZH制备的Cur-Ps具有更好的胶体稳定性。体外释放研究表明,ZH及ZH-SSPS分别制备的Cur-Ps都具有一定的缓释作用,但ZH-SSPS制备的Cur-Ps具有更好的缓释效果,6 h的累积释放率在80%以下。1,1-二苯基-2-苦基肼(1,1-Diphenyl-2-picrylhydrazyl,DPPH)游离基氧化稳定性试验表明,姜黄素经纳米包埋后其氧化稳定性得到了显著提高(P<0.05)。此外,ZH-SSPS制备的Cur-Ps冻干粉呈现多孔的海绵状结构,其复溶率显著提高(P<0.05),可达90%以上。因此,SSPS和ZH在制备Cur-Ps的过程中具有明显的协同作用。利用ZH-SSPS制备的Cur-Ps溶液,外观澄清透明,能够为功能性饮料的营养强化提供借鉴。

Water soluble curcumin nanoparticles （Cur-Ps） were prepared by the simple anti-solvent nanoprecipitation method, using soluble soybean polysaccharide （SSPS） and zein hydrolysate （ZH） as carriers, and the synergistic effect of SSPS and ZH in prepration of Cur-Ps was studied. We expect to provide a new carrier for preparation of Cur-Ps with excellent colloid and oxidation stability. Attributed to poor water solubility of curcumin, the solution of curcumin monomers in deionized water was very turbid. However, the existence of ZH or ZH-SSPS solubilized the curcumin tremendously. The solutions of ZH and ZH-SSPS containing curcumin were yellow and highly transparent. The solubilization results shown that the water solubility of curcumin in ZH solution could reach up to 135μg/mL when the concentration of ZH was above 2.5 mg/mL, and the addition of SSPS had no effect on the water solubility of curcumin at this concentration. But, when the concentration of ZH was below 2.5 mg/mL, the water solubility of curcumin was enhanced slightly with the addition of SSPS. In pure SSPS solution with a concentration of 3 mg/mL, the solubility of curcumin was only 90μg/mL, obviously lower than that in ZH solution with the same concentration. These results suggested that ZH plays a leading role in curcumin solubilization in the ZH-SSPS mixture system and this solubiliazation should attributed to the non-covalent interactions between ZH and curcumin, which leading to the formation of ZH-curcumin nanocomplex. Colloidal stability results indicated that at low ionic strength （〈 50 mmol/L） or under neutral condition （pH value 7.0）, the existence of SSPS had no influence on the particle size distribution of Cur-Ps. However, since SSPS can increase the stability of the protein under acidic and salt-containing solutions, compared with Cur-Ps prepared by ZH only, Cur-Ps fabricated by ZH-SSPS had better colloid stability in solutions with low pH value （4.5 or 2.0） or high ionic strength （〉200 mmol/L）. Hence, due to the synergistic effect of ZH and SSPS, the curcumin-loaded nanoparticles with small size （〈 100 nm） and good colloidal stability can be fabricated. The vitro release study in ethanol-water two-phase system indicated that both Cur-Ps prepared by ZH only and ZH-SSPS solutions had controlled-release effect on curcumin. However, Cur-Ps prepared by ZH-SSPS had better controlled-release effect, and its cumulative release ratio was below 80% in 6 h. The counterpart prepared by ZH only was above 85%. The study on the 1,1-Diphenyl-2-picrylhydrazyl （DPPH） radical oxidation stability of curcumin nanoparticles indicated that the stability of the curcumin was significantly （P〈0.05） improved after the nano-capsulation by ZH or ZH-SSPS. This result is mainly due to the shielding effect for curcumin nano-canpsulation as well as the strong antioxidant effect of ZH. The lyophilized Cur-Ps powder prepared by ZH-SSPS had a multihole spongy structure in field emission images by scanning electron microscopy （SEM）, which resulted in its redispersibility as high as 90%, showing a significant （P〈0.05） improvement compared with the Cur-Ps fabricated by ZH only. Besides, using ZH-SSPS to prepare Cur-Ps powder had a more curcumin content compared with the counterpart. In conclusion, owing to the synergistic effect between ZH and SSPS, ZH-SSPS is expected to be a new material for the preparation of water soluble Cur-Ps. Due to the transparent appearance of the Cur-Ps solution, it has a good prospect in preparation of curcumin-enriched functional drinks.