Structure, Hydration, and Interactions of Native and Hydrophobically Modified Phytoglycogen Nanoparticles

Area of Science:

• Biomaterials Science
• Nanotechnology
• Polymer Chemistry

Background:

• Phytoglycogen nanoparticles, derived from sweet corn, are biodegradable, non-toxic, and possess unique properties like softness and porosity.
• These nanoparticles show promise for personal care and biomedical applications.
• Chemical modification, particularly with octenyl succinic anhydride (OSA), can expand their utility.

Purpose of the Study:

• To develop a self-consistent model for the structure, water content, and modification of phytoglycogen nanoparticles.
• To investigate structural changes in OSA-modified phytoglycogen nanoparticles using small-angle neutron scattering (SANS).
• To elucidate the impact of varying degrees of substitution (DS) on nanoparticle morphology.

Main Methods:

• Small-angle neutron scattering (SANS) was employed on aqueous dispersions of native and OSA-modified phytoglycogen nanoparticles.
• Isotopic variants of OSA (protonated and deuterated) were used to enhance scattering contrast.
• Analysis focused on particle morphology, water content, and interparticle spacing.

Main Results:

• Native phytoglycogen nanoparticles were modeled as hairy particles (core-chain geometry).
• OSA modification led to structural changes, with low DS showing lightly modified hairy chains and high DS resulting in a raspberry particle geometry.
• Well-defined interparticle spacings were observed in concentrated dispersions.

Conclusions:

• A refined structural model for native and OSA-modified phytoglycogen nanoparticles was established.
• The study provides a quantitative basis for understanding how hydrophobic modification influences nanoparticle structure.
• These findings support the development of novel applications for this sustainable nanotechnology.