Cigdem Yucel Falco1, Javier Sotres2, Ana Rascón3, Jens Risbo4, Marité Cárdenas5. 1. University of Copenhagen, Department of Food Science, Rolighedsvej 30, DK-1958 Frederiksberg, Copenhagen, Denmark. 2. Malmö University, Biomedical Laboratory Science and Biofilm - Research Center for Biointerfaces, Faculty of Health and Society, SE-20506 Malmö, Sweden. 3. Lund University, Food for Health Science Centre, 22100 Lund, Sweden. 4. University of Copenhagen, Department of Food Science, Rolighedsvej 30, DK-1958 Frederiksberg, Copenhagen, Denmark. Electronic address: jri@food.ku.dk. 5. Malmö University, Biomedical Laboratory Science and Biofilm - Research Center for Biointerfaces, Faculty of Health and Society, SE-20506 Malmö, Sweden; University of Copenhagen, Department of Chemistry, Universitetsparken 5, DK-2100 Copenhagen, Denmark. Electronic address: marite.cardenas@mah.se.
Abstract
HYPOTHESIS: 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. EXPERIMENT: 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. FINDINGS: 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.
HYPOTHESIS: 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. EXPERIMENT: 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. FINDINGS: 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.