Meng Fan-Tao, Zhang Wan-Zhong, Ma Guang-Hui, Su Zhi-Guo
National Key Laboratory of Biochemical Engineering, Institute of Process Engineering, Chinese Academy of Science, Beijing, PR China.
Artif Cells Blood Substit Immobil Biotechnol. 2003 Aug;31(3):279-92. doi: 10.1081/bio-120023158.
Methoxypoly(ethylene glycol)-b-poly-DL-lactide (PELA) microcapsules containing bovine hemoglobin (bHb) were prepared by a W/O/W double emulsion-solvent diffusion process. bHb solution was used as the internal aqueous phase, PELA/organic solvent as the oil phase, and polyvinyl alcohol (PVA) solution as the external aqueous phase. This W/O/W double emulsion was added into a large volume of water (solidification solution) to allow organic solvent to diffuse into water. The optimum preparative condition for PELA microcapsules loaded with bovine hemoglobin was investigated. It was found that homogenization rate, type of organic solvent, and volume of the solidification solution influenced the activity of bovine hemoglobin encapsulated. When the homogenization rate was lower than 9000 rpm and ethyl acetate was used as the organic solvent, there was no significant influence on the activity of hemoglobin. High homogenization rate as 12 000 rpm decreased the P50 and Hill coefficient. Increasing the volume of solidification solution had an effect of improving the activity of microencapsulated hemoglobin. The composition of the PELA had the most important influence on the success of encapsulation. Microcapsules fabricated by PELA with MPEG2k block (molecular weight of MPEG block: 2000) achieved a high entrapment efficiency of 90%, better than PL A homopolymer and PELA with MPEG5k blocks. Hemoglobin microcapsules with native loading oxygen activity (P50 = 26.0 mmHg, Hill coefficient = 2.4), mean size of about 10 microm, and high entrapment efficiency (ca. 93%) were obtained at the optimum condition.
采用W/O/W双乳液-溶剂扩散法制备了包载牛血红蛋白（bHb）的甲氧基聚（乙二醇）-b-聚-DL-丙交酯（PELA）微胶囊。以bHb溶液为内水相，PELA/有机溶剂为油相，聚乙烯醇（PVA）溶液为外水相。将该W/O/W双乳液加入大量水中（固化溶液），使有机溶剂扩散到水中。研究了PELA微胶囊包载牛血红蛋白的最佳制备条件。结果表明，均质速率、有机溶剂类型和固化溶液体积对包封的牛血红蛋白活性有影响。当均质速率低于9000 rpm且使用乙酸乙酯作为有机溶剂时，对血红蛋白活性无显著影响。12000 rpm的高均质速率降低了P50和希尔系数。增加固化溶液体积有提高微囊化血红蛋白活性的作用。PELA的组成对包封的成功有最重要的影响。由具有MPEG2k嵌段（MPEG嵌段分子量：2000）的PELA制备的微胶囊实现了90%的高包封率，优于PLA均聚物和具有MPEG5k嵌段的PELA。在最佳条件下获得了具有天然载氧活性（P50 = 26.0 mmHg，希尔系数 = 2.4）、平均粒径约为10微米且包封率高（约93%）的血红蛋白微胶囊。
