3B's Research Group-Biomaterials, Biodegradables and Biomimetics, University of Minho, Headquarters of the European Institute of Excellence on Tissue Engineering and Regenerative Medicine, AvePark, S. Cláudio do Barco, 4806-909 Taipas, Guimarães, Portugal.
Colloids Surf B Biointerfaces. 2011 Jun 1;84(2):498-507. doi: 10.1016/j.colsurfb.2011.02.005. Epub 2011 Mar 3.
Poly(butylene succinate) (PBSu), poly(butylene succinate-co-adipate) (PBSA) and poly(butylene terephthalate-co-adipate) (PBTA) microcapsules were prepared by the double emulsion/solvent evaporation method. The effect of polymer and poly(vinyl alcohol) (PVA) concentration on the microcapsule morphologies, drug encapsulation efficiency (EE) and drug loading (DL) of bovine serum albumin (BSA) and all-trans retinoic acid (atRA) were all investigated. As a result, the sizes of PBSu, PBSA and PBTA microcapsules were increased significantly by varying polymer concentrations from 6 to 9%. atRA was encapsulated into the microcapsules with an high level of approximately 95% EE. The highest EE and DL of BSA were observed at 1% polymer concentration in values of 60 and 37%, respectively. 4% PVA was found as the optimum concentration and resulted in 75% EE and 14% DL of BSA. The BSA release from the capsules of PBSA was the longest, with 10% release in the first day and a steady release of 17% until the end of day 28. The release of atRA from PBSu microcapsules showed a zero-order profile for 2 weeks, keeping a steady release rate during 4 weeks with a 9% cumulative release. Similarly, the PBSA microcapsules showed a prolonged and a steady release of atRA during 6 weeks with 12% release. In the case of PBTA microcapsules, after a burst release of 10% in the first day, showed a parabolic release profile of atRA during 42 days, releasing 36% of atRA.
聚丁二酸丁二醇酯（PBSu）、聚丁二酸丁二醇酯-己二酸酯（PBSA）和聚对苯二甲酸丁二醇酯-己二酸酯（PBTA）微胶囊采用双乳液/溶剂蒸发法制备。研究了聚合物和聚乙烯醇（PVA）浓度对微胶囊形态、牛血清白蛋白（BSA）和全反式视黄酸（atRA）的包封效率（EE）和载药量（DL）的影响。结果表明，通过将聚合物浓度从 6%变化到 9%，PBSu、PBSA 和 PBTA 微胶囊的粒径显著增大。atRA 的包封率约为 95%。在聚合物浓度为 1%时，BSA 的 EE 和 DL 最高，分别为 60%和 37%。发现 4%的 PVA 是最佳浓度，可使 BSA 的 EE 达到 75%，DL 达到 14%。BSA 从 PBSA 胶囊中的释放时间最长，第 1 天释放 10%，第 28 天稳定释放 17%。PBSu 微胶囊中 atRA 的释放呈现零级释放模式，在 4 周内保持稳定的释放速率，累积释放率为 9%。类似地，PBSA 微胶囊在 6 周内表现出 atRA 的延长和稳定释放，释放量为 12%。对于 PBTA 微胶囊，在第 1 天有 10%的突释后，在 42 天内呈现出 atRA 的抛物线释放曲线，释放了 36%的 atRA。
