Optimization of Alginate-Whey Protein Isolate Microcapsules for Survivability and Release Behavior of Probiotic Bacteria.

The present study aimed to improve the survivability of L. acidophilus encapsulated in alginate-whey protein isolate (AL-WPI) biocomposite under simulated gastric juice (SGJ) and simulated intestinal juice (SIJ). Microcapsules were prepared based on emulsification/internal gelation technique. Optimal compositions of AL and WPI and their ratio in the aqueous phase were evaluated based on minimizing mean diameter (MD) of the microcapsules and maximizing encapsulation efficiency (EE), survivability of cells under SGJ (Viability), and release of viable cells under SIJ (Release) using Box-Behnken experimental design. Optimal composition comprising 4.54% (w/v) AL, 10% (w/v) WPI, and 10% (v/v) AL-WPI gum in the aqueous phase was determined statistically. Physicochemical characteristics of the optimized matrix were investigated by SEM, FTIR, and XRD analysis to determine surface morphology, molecular bonds, and crystalline nature of such hydrocolloid. It could be concluded that the proposed biocomposite is a good promise for nutrients encapsulation in the food industry.

Encapsulation of mesenchymal stem cells in glycosaminoglycans-chitosan polyelectrolyte microcapsules using electrospraying technique: Investigating capsule morphology and cell viability.

Polyelectrolyte microcapsules are modular constructs which facilitate cell handling and assembly of cell-based tissue constructs. In this study, an electrospray (ES) encapsulation apparatus was developed for the encapsulation of mesenchymal stem cells (MSCs). Ionic complexation between glycosaminoglycans (GAGs) and chitosan formed a polyelectrolyte complex membrane at the interface. To optimize the capsules, the effect of voltage, needle size and GAG formulation on capsule size were investigated. It was observed that by increasing the voltage and decreasing the needle size, the capsule size would decrease but at voltages above 12 kV, capsule size distribution broadened significantly which yields lower circularity. Increase in GAG viscosity resulted in larger microcapsules and cell viability exhibited no significant changes during the encapsulation procedure. These results suggest that ES is a highly efficient, and scalable approach to the encapsulation of MSCs for subsequent use in bioprinting and other modular tissue engineering or regenerative medicine applications.