Yucel Falco Cigdem, Sotres Javier, Rascón Ana, Risbo Jens, Cárdenas Marité
University of Copenhagen, Department of Food Science, Rolighedsvej 30, DK-1958 Frederiksberg, Copenhagen, Denmark.
Malmö University, Biomedical Laboratory Science and Biofilm - Research Center for Biointerfaces, Faculty of Health and Society, SE-20506 Malmö, Sweden.
J Colloid Interface Sci. 2017 Feb 1;487:97-106. doi: 10.1016/j.jcis.2016.10.019. Epub 2016 Oct 12.
Chitosan and sulfated oat β-glucan are materials suitable to create a prebiotic coating for targeted delivery to gastrointestinal system, using the layer by layer technology.
Quartz crystal microbalance with dissipation (QCM-D), spectroscopic ellipsometry (SE) and atomic force microscopy (AFM) were used to assess the multilayer formation capacity and characterize the resulting coatings in terms of morphology and material properties such as structure and rigidity. The coating of colloidal materials was proven, specifically on L. acidophilus bacteria as measured by changes in the bacterial suspension zeta potential. Viability of coated cells was shown using plate counting method. The coatings on solid surfaces were examined after exposure to mimics of gastrointestinal fluids and a commercially available β-glucanase.
Successful build-up of multilayers was confirmed with QCM-D and SE. Zeta potential values proved the coating of cells. There was 2 log CFU/mL decrease after coating cells with four alternating layers of chitosan and sulfated β-glucan when compared to viability of uncoated cells. The coatings were partially degraded after exposure to simulated intestinal fluid and restructured as a result of β-glucanase treatment, mimicking enzymes present in the microflora of the human gut, but seemed to resist acidic gastric conditions. Therefore, coatings of chitosan and sulfated β-glucan can potentially be exploited as carriers for probiotics and delicate nutraceuticals.
壳聚糖和硫酸化燕麦β-葡聚糖是适合利用层层技术制备用于靶向递送至胃肠道系统的益生元涂层的材料。
采用带耗散监测的石英晶体微天平（QCM-D）、椭圆偏振光谱法（SE）和原子力显微镜（AFM）来评估多层膜形成能力，并从形态和材料特性（如结构和刚性）方面对所得涂层进行表征。通过细菌悬浮液ζ电位的变化证实了胶体材料在嗜酸乳杆菌上的涂层。使用平板计数法显示了包被细胞的活力。在将固体表面的涂层暴露于模拟胃肠液和市售β-葡聚糖酶后，对其进行了检查。
QCM-D和SE证实了多层膜的成功构建。ζ电位值证明了细胞被包被。与未包被细胞的活力相比，用壳聚糖和硫酸化β-葡聚糖的四层交替层包被细胞后，细胞活力降低了2 log CFU/mL。暴露于模拟肠液后，涂层部分降解，并由于β-葡聚糖酶处理而重构，模拟了人类肠道微生物群中存在的酶，但似乎能抵抗酸性胃环境。因此，壳聚糖和硫酸化β-葡聚糖涂层有可能被用作益生菌和精致营养保健品的载体。
