Synthesis of monodisperse starch microparticles through molecular rearrangement of short-chain glucans from natural waxy maize starch.

Here, we report a sustainable approach for the synthesis of starch-based microparticles with well-defined shape and size through molecular self-assembly of short-chain glucan (SCG) obtained enzymatically from waxy maize starch. We employed chitosan as a steric stabilizer to modulate the nucleation process, which significantly reduced undesirable aggregations during the nucleation and growth phases, resulting in the production of highly monodisperse microparticles. The size of chitosan-assisted starch microparticles (CS-SMPs) was effectively controlled by the concentration of debranching enzyme as well as by debranching time, of which the factors influencing the final size were investigated. By modulating the rate and time of debranching reaction in combination with the steric stabilizing effect of chitosan, we were able to prepare highly monodisperse CS-SMPs from 200 nm to 5 μm with a production yield of over 70% from natural starch. Furthermore, the potential of CS-SMPs as a carrier system for oral delivery of bioactive compounds were demonstrated using model guest molecules.