Layer-by-layer coating of alginate matrices with chitosan-alginate for the improved survival and targeted delivery of probiotic bacteria after oral administration
Layer-by-layer coating of alginate matrices with chitosan-alginate for the improved survival and targeted delivery of probiotic bacteria after oral administration
复制标题
DOI：
10.1039/c2tb00126h
复制
发表时间：
2013-01-01
影响因子：
7
通讯作者：
Charalampopoulos, Dimitris
中科院分区：
文献类型：
--
作者：
Cook, Michael T.;Tzortzis, George;Charalampopoulos, Dimitris
口服益生菌在临床试验中显示出缓解胃肠道特定疾病的潜力。然而，细胞必须存活才能发挥这些益处。胃的低pH值会大大减少到达肠道的活微生物数量，从而降低给药功效。在此，一种模型益生菌短双歧杆菌被封装到藻酸盐基质中，然后涂上多层交替的藻酸盐和壳聚糖。该配方的目的是提高短双歧杆菌在低 pH 条件下的存活率，并将细胞输送到肠道。在体外测试之前首先对材料特性进行表征。 Biacore (TM) 实验可以确认聚合物之间的相互作用；此外，还证明了这些多层膜对模拟胃肠道 pH 值的缓冲液的稳定性。使用质地分析来监测制备过程中凝胶强度的变化，显示由于钙离子螯合而导致包衣过程中基质的弱化。共焦激光扫描显微镜证实了多层膜的形成，这也表明涂层厚度随着时间的推移而增加。在暴露于体外胃条件期间，存活率增加
The oral administration of probiotic bacteria has shown potential in clinical trials for the alleviation of specific disorders of the gastrointestinal tract. However, cells must be alive in order to exert these benefits. The low pH of the stomach can greatly reduce the number of viable microorganisms that reach the intestine, thereby reducing the efficacy of the administration. Herein, a model probiotic, Bifidobacterium breve, has been encapsulated into an alginate matrix before coating in multilayers of alternating alginate and chitosan. The intention of this formulation was to improve the survival of B. breve during exposure to low pH and to target the delivery of the cells to the intestine. The material properties were first characterized before in vitro testing. Biacore (TM) experiments allowed for the polymer interactions to be confirmed; additionally, the stability of these multilayers to buffers simulating the pH of the gastrointestinal tract was demonstrated. Texture analysis was used to monitor changes in the gel strength during preparation, showing a weakening of the matrices during coating as a result of calcium ion sequestration. The build-up of multilayers was confirmed by confocal laser-scanning microscopy, which also showed the increase in the thickness of coat over time. During exposure to in vitro gastric conditions, an increase in viability from