Design of starch-formate compound fibers as encapsulation platform for biotherapeutics

Effective encapsulation and protection of biotherapeutics using a bio-based carrier, preferably issued from renewable resources, remains a challenge. Herein, we demonstrate application of coaxial electro-spinning to fabric starch-based core-sheath compound fibers as a bacterial cells' carrier. Starch-formate is employed as an encapsulation agent, while the fiber core is made of glycerol, serving as a cell suspension medium. SEM microscopy reveals a distinct core-sheath morphology of the starch-formate/glycerol (SFG) compound fibers with mean diameters of 4.13 +/- 1.05 mu m. Calorimetric and thermomechanical analyses and FTIR spectroscopy show a progressive interaction between the starch-formate and the glycerol with time, pronounced with temperature increase. SFG fibers with encapsulated Lactobacillus paracasei are proved stable with retained bacterial viability when stored at 4 degrees C and room temperature for up to 21 days. SFG fibers present a potential biotherapeutic products', encapsulation platform, guaranteeing the stability at refrigerated and ambient storage conditions, as determined in this study. (C) 2016 Elsevier Ltd. All rights reserved.