Dense Packing of Soft Phytoglycogen Nanoparticles: Insight into the Compressibility and Radial Particle Density

Phytoglycogen is a natural polysaccharide produced in the form of compact 35 nm diameter nanoparticles by some varieties of plants such as sweet corn. The highly-branched, dendrimeric structure of phytoglycogen leads to interesting and useful properties that make the particles ideal as unique additives in personal care, nutrition and biomedical formulations. Equilibrium osmotic pressure measurements of aqueous phytoglycogen dispersions allow the determination of the compressional modulus of the particles and add additional insight into their internal structure. Osmotic pressure measurements of native and acid hydrolyzed particles, together with tracking of the particle diameter during acid hydrolysis, are consistent with a new model of phytoglycogen nanoparticle structure consisting of a dense core and less dense shell. These results suggest new possibilities for the attachment and encapsulation of bioactive compounds.