Structure of Hydrophobically Modified Phytoglycogen Nanoparticles Using Small Angle Neutron Scattering

Phytoglycogen is a polysaccharide produced in the form of compact nanoparticles by sweet corn. The nanoparticles have exceptional properties that emerge from their highly-branched, dendrimeric structure and their unique interaction with water, which makes them desirable as additives for applications in personal care, food and biomedicine. Our initial small angle neutron scattering (SANS) study on phytoglycogen nanoparticles [1] revealed unique insights into their structure and hydration. By hydrophobically modifying the hydrophilic nanoparticles, we can change the nature of their interactions in a tunable manner. Specifically, we modified phytoglycogen nanoparticles by covalently attaching octenyl succinate anhydride (OSA), for which the octenyl groups convey a hydrophobic character. We used small angle neutron scattering at the Oak Ridge National Laboratory to perform a comprehensive study of OSA-modified phytoglycogen with different degrees of substitution. We synthesized deuterated OSA (dOSA) and used dOSA-phytoglycogen and OSA-phytoglycogen in contrast series SANS experiments to create a comprehensive picture of the radial distribution of the OSA molecules on the phytoglycogen nanoparticles.
[1] J.D. Nickels, et al., Biomacromolecules 17 (3), 735-743 (2016).