MSc Candidate

Yasmeen El-Rayyes

Abstract

Phytoglycogen (PG) is a compact nanoparticle with dendritic architecture that is produced in sweet corn. Its deformability and biocompatibility make PG nanoparticles ideal for applications in personal care, nutraceuticals, and drug delivery. Chemical modifications tune the physical and chemical properties of the particles, adapting them for specific applications. We performed acid hydrolysis, a process where bonds between the glucose subunits are broken with dilute acid at elevated temperature, and measured changes to the radius and Young's modulus of the particles. I used light scattering to measure the radius and molecular weight of the acid-hydrolyzed particles, and atomic force microscopy force spectroscopy to generate high resolution maps of the Young’s modulus of the particles, characterizing the dependence of the particles’ size and deformability on the hydrolysis time. Intermediate hydrolysis times produced changes in the inner and outer regions of PG, whereas long hydrolysis times produced significant overall decreases in modulus. Additional measurements using dynamic light scattering and size exclusion chromatography-multiangle light scattering provided further insight into the modified particles’ size and shape.

Examination Committee

• Dr. Hermann Eberl, Chair 
• Dr. John Dutcher, Advisor 
• Dr. Erica Pensini, Advisory Committee 
• Dr. Robert Wickham, Graduate Faculty