Synthesis of β-1,3-glucan esters showing nanosphere formation.

Polysaccharide nanoparticles are versatile functional materials used in drug delivery applications. Here we describe a method for the synthesis of β-1,3-glucan esters which show the formation of nanoparticles. Pyridine-soluble β-1,3-glucan formate was first synthesized as an intermediate and then reacted with various anhydrates to yield β-1,3-glucan acetate and hexaonate. The resultant esters were soluble in common organic solvents like acetone, pyridine and dimethylacetamide. By using a simple dialysis process, homogeneous hollow or solid nanospheres with diameter from 132 to 487 nm were prepared. The chemical structures of the obtained β-1,3-glucan esters were characterized and the morphologies of the β-1,3-glucan based nanoparticles were evaluated. These new types of nanoparticles could be potentially used for the encapsulation of hydrophobic drugs targeting immune cells.