负载姜黄素的玉米醇溶蛋白-多糖纳米颗粒的制备及生物活性研究

目的 制备负载姜黄素的玉米醇溶蛋白-多糖纳米颗粒及评价其生物活性.方法 以反溶剂法和静电沉积法制备负载姜黄素的核/壳型复合纳米颗粒,以扫描电镜观察形貌,DPPH·法测定抗氧化活性,平板抑菌试验测定抗菌活性,模拟体外消化试验测定消化吸收率.结果 纳米颗粒为表面光滑的球形,平均粒径为133 nm;姜黄素纳米颗粒对DPPH·自由基的清除率明显高于姜黄素乙醇溶液,清除率分别为(13.89±0.69)、(16.73±0.097) μg/mL;纳米颗粒的抑菌效果较差;纳米颗粒包埋的姜黄素消化吸收率提高了4倍.结论 纳米颗粒包埋的姜黄素具有较高的抗氧化活性及消化吸收率,在功能性食品及药物方面有良好的应用前景.     

羧甲基玉米朊阿司匹林肠溶微丸的制备及体外释放度考察

目的:制备羧甲基玉米朊阿司匹林肠溶微丸,并考察其在大鼠体内的药动学特征。方法:以羧甲基玉米朊为肠溶材料,与阿司匹林按2∶1混合,加入乙醇作为黏合剂,采用挤压滚圆法制备羧甲基玉米朊阿司匹林肠溶微丸。以阿司匹林微丸作为参比制剂,考察受试制剂羧甲基玉米朊阿司匹林肠溶微丸灌胃给予15 mg/kg后在大鼠体内48 h内的药动学特征和4 h(前2 h在人工胃液中,后2 h在人工肠液中)内的体外释放度(n=5)。结果:所制羧甲基玉米朊阿司匹林肠溶微丸粒径为1 mm,规格为每丸3 mg。受试制剂与参比制剂的药动学特征均符合二室模型,主要药动学参数分别为t1/2β:(12.63±0.60)、(2.42±0.61)h,tmax:(11.07±1.10)、(3.41±0.84)h,cmax:(34.45±5.33)、(45.78±3.30)μg/ml,AUC0-∞:(613.52±41.14)、(550.69±34.44)μg·h/ml;与参比制剂比较,受试制剂的t1/2β、tmax、AUC0-∞均明显增加,cmax明显减小(P<0.05)。参比制剂2 h的累积释放度为87%,受试制剂2 h的累积释放度为1.7%、3 h的累积释放度达100%。结论:成功制得体外释放符合肠溶制剂要求的羧甲基玉米朊阿司匹林肠溶微丸。     

Hot-melt extrusion microencapsulation of quercetin for taste-masking

Besides its poor dissolution rate, the bitterness of quercetin also poses a challenge for further development. Using carnauba wax, shellac or zein as the shell-forming excipient, this work aimed to microencapsulate quercetin by hot-melt extrusion for taste-masking. In comparison with non-encapsulated quercetin, the microencapsulated powders exhibited significantly reduced dissolution in the simulated salivary pH 6.8 medium indicative of their potentially good taste-masking efficiency in the order of zein?>?carnauba wax?>?shellac. In vitro bitterness analysis by electronic tongue confirmed the good taste-masking efficiency of the microencapsulated powders. In vitro digestion results showed that carnauba wax and shellac-microencapsulated powders presented comparable dissolution rate with the pure quercetin in pH 1.0 (gastric) and 6.8 (intestine) medium; while zein-microencapsulated powders exhibited a remarkably slower dissolution rate. Crystallinity of quercetin was slightly reduced after microencapsulation while its chemical structure remained unchanged. Hot-melt extrusion microencapsulation could thus be an attractive technique to produce taste-masked bioactive powders.     

Impact of Solvent on Electrospinning of Zein and Analysis of Resulting Fibers

Zein fibers have been produced by electrospinning from acetic acid, aqueous methanol, ethanol and isopropyl alcohol. Alcohol solutions produced fibers that were predominantly ribbons. Fibers spun from acetic acid solution have a round morphology with a narrower distribution of diameters when spun under suitable conditions. The IR spectra of electrospun fibers display increased absorbance at 1 650 cm^?1 relative to starting material, indicative of increased α‐helical structure. Raman spectra of fibers spun from acetic acid solution had spectral differences, having increased absorbance at 680, 750 and 860 cm^?1, versus fibers spun from alcoholic solvents suggesting different tertiary structure within the fiber, which may result from different structures in solution. Polarized Raman spectroscopy taken parallel and perpendicular to the fiber axis displayed no differences, suggesting similar secondary and tertiary structures in these directions. All of the fibers had some degree of birefringence demonstrating the presence of orientation. The smaller fibers were highly birefringent throughout the fiber, while the larger fibers had orientation at the surface only. Quality fibers could not be produced from N,N‐dimethylformamide, acetone/water, acetic acid/water, 8 M urea/water or 10% NaOH/water zein solutions.

     

三七总皂苷玉米脂蛋白纳米粒对大鼠脑缺血再灌注损伤的药效学研究

对三七总皂苷（Panax notoginseng saponins,PNS）与卵磷脂、β-谷甾醇、玉米醇溶蛋白共组装制备的三七总皂苷玉米脂蛋白纳米粒（PNS-lipid-zein nanoparticles,PLZ-NPs）进行了体外细胞实验,以及大鼠脑缺血再灌注损伤的药效学研究。采用反溶剂沉淀法制备了PLZ-NPs,运用激光粒度仪和透射电镜显微镜对纳米粒进行表征,MTT法评价了纳米粒的细胞毒性,激光共聚焦和流式细胞术分析了Caco-2细胞对纳米粒的摄取情况。大脑中动脉闭塞（MCAO）法构建了大鼠脑缺血再灌注损伤模型,连续3 d灌胃给药后,取脑组织进行2,3,5-氯化三苯基四氮唑（TTC）染色,并检测脂质过氧化物丙二醛（MDA）、炎症因子IL-1β、TNF-α、凋亡相关蛋白Bax、Bcl-2的水平。结果显示,PLZ-NPs平均粒径为（116.4 ± 0.81）nm,PDI为0.048,Zeta电位为-（31.5 ± 0.31）mV。MTT实验表明,玉米脂蛋白载体的生物安全性良好,且能显著提高Caco-2细胞对纳米粒的摄取（纳米粒组在4 h时细胞摄取量提高至游离组的1.76倍）。TTC染色中,PNS和PLZ-NPs组的梗死面积比模型组均有减少,另外MDA、IL-1β、TNF-α、Bax的含量明显下降,Bcl-2含量增加,而且PLZ-NPs组对脑缺血再灌注损伤的保护作用显著优于PNS组（P<0.05）。实验结果表明,本实验制备的玉米脂蛋白纳米粒具有良好的稳定性、药物负载能力和生物安全性,能显著提高肠上皮细胞对药物的摄取,有效改善脑缺血再灌注对大鼠造成的损伤。     

中药双黄补对人牙周膜细胞在玉米醇溶蛋白支架材料上黏附生长及增殖的影响

目的 研究中药双黄补对人牙周膜细胞(human periodontal ligament cells,HPDLCs)在玉米醇溶蛋白(Zein)支架材料上黏附生长及增殖的影响,探讨双黄补-Zein作为一种复合支架材料应用于牙周组织工程的可行性。     

Impact of Microfluidization on the Emulsifying Properties of Zein-Based Emulsions: Influence of Diutan Gum Concentration

Microfluidization is a preparation method that can be used to obtain emulsions with submicron droplet sizes. The first objective of this study was to evaluate the influence of homogenization pressure and cycles on droplet sizes using response surface methodology. Secondly, the influence of the diutan gum concentration incorporated in the optimized emulsion on rheological properties, microstructure, and physical stability was investigated. Taking the response surface analysis into account, the emulsion processed at 20,000 psi after four cycles seemed to show the smallest Sauter diameter values. Hence, this emulsion was the starting point to incorporate diutan gum. Interestingly, the formation of a 3D network in the emulsion, observed by FESEM, was provoked by diutan gum. The emulsion formulated with 0.4 wt.% of diutan gum presented rheological gel properties and enhanced physical stability. This work highlights the importance of selecting optimized processing variables using the microfluidization technique and extends the knowledge of using diutan gum in combination with zein.     

Electrospun Zein Fibers Using Glutaraldehyde as the Crosslinking Reagent: Effect of Time and Temperature

Glutaraldehyde was used as a crosslinking reagent to produce electrospun zein fibers with improved physical properties and solvent resistance. Using 8% glutaraldehyde, round and ribbon fibers were produced with diameters between 1 and 70 µm. All fibers readily dissolved in acetic acid. Heating the zein/glutaraldehyde fibers at temperatures from 80 to 180 °C for different times provided various degrees of insolubility to the fibers. A model was developed relating the extent of dissolution with the amount of glutaraldehyde used and the temperature/time at which the fiber was exposed. The fibers were found to be birefringent; upon heating, the amount of α‐helix in the fiber was reduced.