Qi Wei, Yan Xuehai, Fei Jinbo, Wang Anhe, Cui Yue, Li Junbai
Beijing National Laboratory for Molecular Sciences, International Joint Laboratory, Key Laboratory of Colloid and Interface Sciences, Institute of Chemistry, Chinese Academy of Sciences, China.
Biomaterials. 2009 May;30(14):2799-806. doi: 10.1016/j.biomaterials.2009.01.027. Epub 2009 Feb 8.
A glucose-sensitive multilayer shell, which was fabricated by the layer-by-layer (LbL) assembly method, can be used as a carrier for the encapsulation and controlled release of insulin. In the present report, glucose oxidase (GOD) and catalase (CAT) were assembled on insulin particles alternately via glutaraldehyde (GA) cross-linking. The resulting core-shell system has been proven to be glucose-sensitive. When the external glucose was introduced, the release ratio of insulin from the protein multilayer can be increased observably. This is likely attributed to the catalysis interaction of CAT/GOD shells to glucose, which leads to the production of H(+) and thus drops the pH of the microenvironment. Under the acidic conditions, on the one hand, a part of C=N bond formed from Schiff base reaction can be broken and thus increasing the permeability of the capsule wall. On the other hand, the solubility of insulin can also be increased. The above factors may be the key control to increase the release of insulin from the multilayer. Therefore, such CAT/GOD multilayer may have a great potential as a glucose-sensitive release carrier for insulin, and may open the way for the further application of LbL capsules in the drug delivery and controlled release, etc.
通过层层组装（LbL）方法制备的葡萄糖敏感多层壳，可作为胰岛素包封和控释的载体。在本报告中，葡萄糖氧化酶（GOD）和过氧化氢酶（CAT）通过戊二醛（GA）交联交替组装在胰岛素颗粒上。所得的核壳系统已被证明对葡萄糖敏感。当引入外部葡萄糖时，胰岛素从蛋白质多层膜中的释放率可显著增加。这可能归因于CAT/GOD壳对葡萄糖的催化相互作用，导致产生H(+)，从而降低微环境的pH值。在酸性条件下，一方面，席夫碱反应形成的部分C=N键会断裂，从而增加胶囊壁的通透性。另一方面，胰岛素的溶解度也会增加。上述因素可能是增加胰岛素从多层膜中释放的关键控制因素。因此，这种CAT/GOD多层膜作为胰岛素的葡萄糖敏感释放载体可能具有巨大潜力，并可能为LbL胶囊在药物递送和控释等方面的进一步应用开辟道路。
