Protein Component of Oyster Glycogen Nanoparticles: An Anchor Point for Functionalization

Abstract

Bio-sourced nanoparticles have a range of desirable properties for therapeutic applications, including biodegradability and low immunogenicity. Glycogen, a natural polysaccharide nanoparticle, has garnered much interest as a component of advanced therapeutic materials. However, functionalizing glycogen for use as a therapeutic material typically involves synthetic approaches that can negatively affect the intrinsic physiological properties of glycogen. Herein, the protein component of glycogen is examined as an anchor point for the photopolymerization of functional poly(N-isopropylacrylamide) (PNIPAM) polymers. Oyster glycogen (OG) nanoparticles partially degrade to smaller spherical particles in the presence of protease enzymes, reflecting a population of surface-bound proteins on the polysaccharide. The grafting of PNIPAM to the native protein component of OG produces OG-PNIPAM nanoparticles of ~45 nm in diameter and 6.2 MDa in molecular weight. PNIPAM endows the nanoparticles with temperatureresponsive aggregation properties that are controllable, reversible, and which can be removed by the biodegradation of the protein. The OG-PNIPAM nanoparticles retain the native biodegradability of glycogen. Whole blood incubation assays revealed that the OG-PNIPAM nanoparticles have a low cell association and inflammatory response similar to that of OG. The reported strategy provides functionalized glycogen nanomaterials that retain their inherent biodegradability and low immune cell association.

From Prokaryotes to Eukaryotes: Insights Into the Molecular Structure of Glycogen Particles

“…The result shows that the radial density reaches maximum close to the center of glycogen particles, which is consistent with random growth pattern of glycogen particles ( Zhang et al, 2018 ). Even more recent work by Besford et al (2020) has again shown these same density distributions (pair-distance distributions) for commercial glycogen beta particle preparations that matches the density observed previously.…”

“… Powell et al (2015) studied size change of glycogen α particles in liver glycogen and phytoglycogen via acid hydrolysis, according to which, formation of α particles in liver glycogen might be due to the linkage of β particles via covalent or strong non-covalent bonds involving proteins. Recently, Besford et al (2020) shows that glycogen particle sizes and shapes change in the presence of protease enzymes that removes proteins from the particles, which reflects that reduction in surface-bound protein leads to the potential cleavage of alpha particles. However, it is currently not clear which protein(s) are involved in glycogen α particle formation.…”

Ultrasound-Assisted Microencapsulation of Soybean Oil and Vitamin D Using Bare Glycogen Nanoparticles

“…The protein content per mass of glycogen nanoparticle was found to be 8 μg/mg for OG, 5.3 μg/mg for BG, 2.9 μg/mg for RG and 1.6 μg/mg for PG [ 32 ]. Previous studies suggest that the protein component of glycogen may be either incorporated within the structure and/or situated on the surface of the particles [ 32 , 36 ].…”

“…The protein content per mass of glycogen nanoparticle was found to be 8 μg/mg for OG, 5.3 μg/mg for BG, 2.9 μg/mg for RG and 1.6 μg/mg for PG [ 32 ]. Previous studies suggest that the protein component of glycogen may be either incorporated within the structure and/or situated on the surface of the particles [ 32 , 36 ]. We have recently shown that the protein component of OG can be exploited as an anchor point for the photopolymerization of poly( N -isopropylacrylamide) chains on the surface of glycogen nanoparticles [ 32 ].…”

Nanoparticle Delivery Platforms for RNAi Therapeutics Targeting COVID-19 Disease in the Respiratory Tract

“…The outer surface of GNPs is highly branched and has a dense inner core. Because of their high hydrophilicity and biocompatibility, they can easily be biochemically modified to produce functional derivatives [ 198 ], such as adhesive GNPs composed of lipoate-conjugated phytoglycogen (L-PG) [ 199 ] and oyster GNPs with poly(N-isopropylacrylamide) (PNIPAM) chains on their surface [ 200 ].…”