Polysaccharide nanofiber made from euglenoid alga

We have fabricated a polysaccharide nanofiber made from paramylon (β-1,3-glucan), a storage polysaccharide stored as a micrometer-sized particle in the cell of euglenoid alga. Preparation of this nanofiber primarily hinges on the bottom-up approach. First, paramylon, which is originally present in the form of a bundle of nanofibers in a particle, was fibrillated to a randomly coiled polymer by dissolving the particle in a 1.0-mol/L NaOH aqueous solution. Second, the randomly coiled polymer was allowed to self-assemble into a triplex as the NaOH concentration was reduced to 0.25–0.20 mol/L. Third, a 20-nm-width nanofiber made from the triplex emerged in the solution when the NaOH concentration was reduced to approximately 0.20 mol/L.

► Triplex and nanofiber made from paramylon were prepared. ► Preparation process hinges on the self-assembly ability of paramylon. ► Fiber width is controlled by adjusting NaOH concentration of paramylon solutions. ► Nanofiber has an ordered structure produced by a hierarchic association process.