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以生物相容性好、价格低廉的海藻酸钠(ALG)为聚阴离子芯材,通过静电液滴装置制备了平均粒径在290μm左右、球形度好、表面光洁的海藻酸钙胶珠;再将生物可降解、具有介入治疗作用的聚精氨酸(PLA)与聚组氨酸(PLH)的混合物作为聚阳离子壁材,在海藻酸钙胶珠表面覆上一层高分子聚合膜以制备聚氨基酸复合微胶囊;并以牛血红蛋白Hb为药物模型,对微胶囊的控制释放性能进行了考察并将其初步应用于体外模拟口服给药。结果表明:聚氨基酸复合微胶囊在前0.5 h的累积释放量均低于40%,溶出结束时累积释放量均达到80%以上;ALG/(PLA-PLH)复合微胶囊和ALG/PLH微胶囊的药物释放速率均低于ALG/PLA微胶囊;于10 min成膜时间内制备的微胶囊具有较高的载药量、包封率和缓释性能;以pH 4.6 HAc-NaAc缓冲液为成膜溶媒制备的微胶囊,Hb持续释放时间和残留量均高于蒸馏水组;前2 h在模拟胃液的pH 1.2 HCl溶媒中累计释放的Hb不超过10%且绝大部分是在模拟肠液环境即pH 6.8 PBS溶媒中释放的;壳聚糖的引入能在一定程度上延长药物释放时间。聚氨基酸复合微胶囊具备一定的缓释性、pH响应性和生理黏附性,有望成为一种口服给药系统用药物载体。
Biocompatible and inexpensive alginate (ALG) was used as the polyanionic core material. Calcium alginate beads with average diameter of 290μm, sphericity and smooth surface were prepared by electrostatic droplet device. A biodegradable, poly-arginine (PLA) polyhistidine (PLH) mixture with intervening therapeutic effects was used as the polycation wall material to coat the surface of the calcium alginate beads with a polymeric polymeric film to prepare Polyamino acid composite microcapsules. The controlled release properties of microcapsules were investigated with bovine hemoglobin Hb as a drug model, and initially applied in vitro to simulate oral administration. The results showed that the cumulative release of polyamino acid composite microcapsules in the first 0.5 h was less than 40%, and the cumulative release of polyamino acid composite microcapsules reached more than 80% at the end of dissolution. The ALG / PLA-PLH composite microcapsules and ALG / PLH microcapsules The drug release rate of ALG / PLA microcapsules was lower than that of ALG / PLA microcapsules. The microcapsules prepared at the time of 10 min exhibited higher drug loading, entrapment efficiency and sustained release performance. The sustained release time and residual amount of Hb in the microcapsules prepared by membrane medium were higher than those in the distilled water group. The cumulative release of Hb in the simulated gastric fluid pH 1.2 HCl medium in the first 2 h did not exceed 10% and most of them were in simulated intestinal fluid environment pH 6.8 PBS vehicle release; the introduction of chitosan can extend the drug release time to a certain extent. Polyamino acid microcapsules with a certain degree of sustained-release, pH-responsiveness and physiological adhesion, is expected to become an oral drug delivery system with a drug carrier.