摘要:
为防止纳豆激酶在胃中失活,提高其在小肠内的吸收能力,本研究以聚乙二醇-聚乳酸-羟基乙酸共聚物(PEG-PLGA)为壁材,以包封率为指标,通过正交实验探究双重乳液蒸发法制备纳豆激酶微胶囊的最适条件,接着采用上述条件分别以PEG-PLGA和叶酸-聚乙二醇-聚乳酸-羟基乙酸共聚物(FA-PEG-PLGA)为壁材制备纳豆激酶微胶囊,最后对两种微胶囊体外缓释效果、细胞毒性及在Caco-2单层细胞模型中的吸收效果进行评价。结果表明,PEG-PLGA纳豆激酶微胶囊最适制备条件为壁材浓度5 mg/mL、聚乙烯醇(PVA)浓度1%、二级均质转速17500 r/min、二级均质时间7.5 min;PEG-PLGA和FA-PEG-PLGA纳豆激酶微胶囊的平均粒径分别为271.33和255.75 nm,包封率分别为61.54%±2.36%和58.76%±2.54%,ζ电位分别为(-20.17±1.42)和(-24.73±2.36) mV。体外模拟缓释结果表明,经胃环境(pH2.0)2 h后,两种微胶囊中超60%纳豆激酶被保留,经肠环境(pH7.0)22 h缓释效果良好。两种微胶囊对Caco-2细胞均无明显毒性且细胞吸收良好,顶侧表观渗透系数分别高达2.367×10-6和3.497×10-6 cm/s,激光共聚焦显微镜观察结果同样表明两种微胶囊在Caco-2细胞中均有很好的吸收效果,且FA-PEG-PLGA微胶囊比PEG-PLGA微胶囊吸收效果更佳。
Abstract:
To protect nattokinase from inactivation and improve its absorption in gastrointestinal tract,the optimum preparation condition of nattokinase microcapsules formed by double emulsion evaporation method was obtained by orthogonal experiment,with poly(ethylene glycol-b-(DL-lactic acid-co-glycolic acid)-b-ethylene glycol)(PEG-PLGA)as the wall material,and entrapment efficiency as the index. Then nattokinase microcapsules were respectively prepared with PEG-PLGA and folate-poly(ethylene glycol-b-(DL-lacticacid-co-glycolic acid)-b-ethylene glycol)(FA-PEG-PLGA)as the wall material,under the optimum condition. Finally,the gastrointestinal release in vitro and cytotoxicity and absorption in Caco-2 monolayer model of the two microcapsules were evaluated. Results showed that,the optimum preparation condition of PEG-PLGA nattokinase microcapsules were listed as follows:Wall material concentration of 5 mg/mL,PVA concentration of 1%,homogenization speed of 17500 r/min and homogenization time of 7.5 min for double emulsion. For PEG-PLGA and FA-PEG-PLGA nattokinase microcapsules,their average particle sizes were 271.33 and 255.75 nm,the encapsulation efficiency was 61.54%±2.36% and 58.76%±2.54%,the Zeta potential was(-20.17±1.42)and(-24.73±2.36) mV,respectively. Results of gastrointestinal release in vitro showed that more than 60% nattokinase was retained in the two microcapsules after 2 h in gastric pH,and the sustained release effect was good in the intestinal environment(pH7.0)within 22 h. Both microcapsules had almost no toxicity to Caco-2 cells at a concentration of 500 μg/mL,and could be well absorbed,the apparent permeation coefficients of the two microcapsules were as high as 2.367×10-6 and 3.497×10-6 cm/s,respectively. Results of laser confocal microscopy also showed that both microcapsules were well absorbed in Caco-2 cells,and FA-PEG-PLGA microcapsules were absorbed better than PEG-PLGA microcapsules.
百度学术
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