In Vitro Enzymatic Polymerization of α-1,6-Graft-α-1,3-glucan and Structural Analysis of Gel Formation

alpha-1,6-Graft-alpha-1,3-glucan comprises a main-chain of alpha-1,6-glucan and side-chains of alpha-1,3-glucan. It was synthesized by a one-pot in vitro enzymatic polymerization of sucrose and dextran (alpha-1,6-glucan) of different molecular weights. In the presence of the high-molecular-weightdextran (M-w >= 650 000), the graft glucan formed a self-standing hydrogel without any cross-linker. It was possible to control the number of alpha-1,3-glucan side-chains by controlling the molecular weight and concentration of the dextran. Consequently, it was possible to control the compression strength of the obtained gels. Hydrogels of the graft glucan were formed by physically cross-linking the alpha-1,3-glucan side-chains. These physical gels are potentially useful biomaterials with high biocompatible, because the graft glucan is composed of glucose alone.