Carboxymethyl konjac glucomannan-chitosan complex nanogels stabilized double emulsions incorporated into alginate hydrogel beads for the encapsulation, protection and delivery of probiotics

In this study, we developed (W-1/O/W-2) double emulsions encapsulated by calcium-alginate hydrogel beads system (ACGs) for intestinal-targeted delivery of probiotics (Lactobacillus reuteri). Firstly, the carboxymethyl konjac glucomannan-chitosan (CMKGM-CS) nanogels were successfully fabricated by EDC/NHS initiated cross linking, as concluded from the TEM images, FTIR spectra, XRD, etc. Then, double emulsions were prepared and encapsulated with various concentrations of alginate to form ACGs hydrogel beads. In vitro probiotic release experiments showed the lyophilized ACG-2 and ACG-3 hydrogel beads had a sustained release in simulated intestinal fluid (SIF), the viability of cells exceeded 10(7) CFU/mL at 6 h. The lyophilized ACG-3 hydrogel beads exhibited the viable release amount of 8.4 x 10(7) CFU/mL after storage for 90 d at 4 degrees C. Besides, the alginate concentration in the ACGs hydrogel beads influences the swelling behavior and structure of hydrogel beads by affecting the hydrogen bonds between alginate and CMKGM-CS, thereby mediating the release of probiotics.

Automated summary

In this study, double emulsions encapsulated by calcium-alginate hydrogel beads system (ACGs) were developed for intestinal-targeted delivery of probiotics. The experimental results showed that ACG-2 and ACG-3 hydrogel beads had sustained release properties in simulated intestinal fluid and high cell viability. Moreover, the alginate concentration in ACGs hydrogel beads influenced the swelling behavior and structure, thus mediating the release of probiotics.