Borodina T N, Rumsh L D, Kunizhev S M, Sukhorukov G B, Vorozhtsov G N, Fel'dman B M, Markvicheva E A
Biomed Khim. 2007 Sep-Oct;53(5):557-65.
Novel biodegradable microcapsules for delivery of biologically active substances (BAS) were prepared by layer-by-layer (LbL) adsorption of oppositely charged polyelectrolytes, namely sodium alginate (Alg) and poly-L-lysine (PLL). To immobilize these BAS, porous spherical CaCO3 microparticles were used as templates. The templates (cores) were coated with several layers of oppositely charged polyelectrolytes forming shell on a core surface. The core-shell microparticles were converted into hollow microcapsules by a core dissolution after an EDTA treatment. Mild conditions for microcapsule fabrication allow to perform an entrapment of various biomolecules while keeping their bioactivity. Biocompatibility and biodegradable capability of the polyelectrolytes give a possibility to use the microcapsules as the target delivery systems. Chymotrypsin (Chym) entrapped into the microcapsules was used as a model enzyme. The immobilized enzyme was found to keep about 86% of the activity compared to a native Chym. The obtained microcapsules were stable at an acidic medium while they could be easily decomposed by trypsin treatment at an slightly alkaline medium. Chym was shown to be active after being released from the microcapsules decomposed by trypsin treatment. Thus, the microcapsules prepared by the LbL - technique can be used for the development of new type of BAS delivery systems in humans and animals.
通过带相反电荷的聚电解质（即海藻酸钠（Alg）和聚-L-赖氨酸（PLL））的逐层（LbL）吸附制备了用于递送生物活性物质（BAS）的新型可生物降解微胶囊。为了固定这些BAS，使用多孔球形碳酸钙微粒作为模板。模板（核）用几层带相反电荷的聚电解质包覆，在核表面形成壳。经乙二胺四乙酸（EDTA）处理后，通过核溶解将核壳微粒转化为中空微胶囊。微胶囊制备的温和条件允许在保持各种生物分子生物活性的同时将其包封。聚电解质的生物相容性和可生物降解能力使得微胶囊有可能用作靶向递送系统。包封在微胶囊中的胰凝乳蛋白酶（Chym）用作模型酶。与天然Chym相比，固定化酶的活性保留约86%。所获得的微胶囊在酸性介质中稳定，而在微碱性介质中经胰蛋白酶处理可容易地分解。经胰蛋白酶处理分解的微胶囊释放后，Chym显示具有活性。因此，通过LbL技术制备的微胶囊可用于开发新型的人类和动物BAS递送系统。
