Surface Modification of Cellulose Nanocrystals (CNCs) to Form a Biocompatible, Stable, and Hydrophilic Substrate for MRI

Abstract

This study focused on surface modification of cellulose nanocrystals (CNCs) to create a biocompatible, stable, and hydrophilic substrate suitable for use as a coating agent to develop a dual-contrast composite material. The CNCs were prepared using acid hydrolysis. Hydrolysis was completed using 64% sulfuric acid at 45 °C for 1 h, which was combined with polyethylene glycol and sodium hydroxide (PEG/NaOH). The yield of samples exhibited prominent physicochemical properties. Zeta (ζ) potential analysis showed that the CNCs sample had excellent colloidal stability with a highly negative surface charge. Transmission electron microscopy (TEM) analysis confirmed that the CNCs sample had a rod-like morphology. On the other hand, field-emission scanning electron microscopy (FESEM) analysis showed that the acid hydrolysis process caused a significant reduction in particle size and changed surface morphology. In addition, cellulose nanocrystals with polyethylene glycol and sodium hydroxide (CNCs-PEG/NaOH) have many noteworthy properties such as colloidal stability, small hydrodynamic size, and water dispersibility. Furthermore, the MTT assay test on Hep G2 cells demonstrated good biocompatibility of the CNCs-PEG/NaOH and did not exhibit any cytotoxic effects. Hence, CNCs-PEG/NaOH holds the potential to serve as a dual-contrast agent for MRI techniques and other biomedical applications.

Innovative ionic liquid pretreatment followed by wet disk milling treatment provides enhanced properties of sugar palm nano-fibrillated cellulose

“…In practical terms, this stability facilitates consistent and uniform dispersion when integrating SPNFC into composite materials or formulations. As the zeta potential is large, it indicates that there is a strong repulsive force between the particles, which improves the stability of the suspended and makes it less probable to flocculate [ 101 ]. In the context of potential interactions with other materials, the negative charge on SPNFC surfaces may influence its compatibility with positively charged components.…”

Production and Characterization of Nanocellulose from Maguey (Agave cantala) Fiber

“…Nanocellulose with a negative zeta potential is highly preferred as it can resist aggregation in a colloidal environment, leading to a wider distribution [49]. The reported zeta potential value presents a more stable dispersed state compared with values between −15 and 15 mV where agglomeration forms due to the lack of necessary charges for a repelling effect [49]. This result implies that the produced nanocellulose would lead to a uniform nanocellulose suspension due to the strong electrostatic repulsive forces [49,50].…”

“…The reported zeta potential value presents a more stable dispersed state compared with values between −15 and 15 mV where agglomeration forms due to the lack of necessary charges for a repelling effect [49]. This result implies that the produced nanocellulose would lead to a uniform nanocellulose suspension due to the strong electrostatic repulsive forces [49,50]. The measurement results can be obtained from Section S.IV.4 in the Supplementary Material.…”

“…The nanocellulose displays a highly negative surface charge with a mean zeta potential value of −37.3 mV. This negative zeta potential was aided by the negative electrostatic layers formed on the nanocellulose due to the grafting of sulfate groups during sulfuric acid hydrolysis that link to the nanocellulose chains [49]. Nanocellulose with a negative zeta potential is highly preferred as it can resist aggregation in a colloidal environment, leading to a wider distribution [49].…”

“…This negative zeta potential was aided by the negative electrostatic layers formed on the nanocellulose due to the grafting of sulfate groups during sulfuric acid hydrolysis that link to the nanocellulose chains [49]. Nanocellulose with a negative zeta potential is highly preferred as it can resist aggregation in a colloidal environment, leading to a wider distribution [49]. The reported zeta potential value presents a more stable dispersed state compared with values between −15 and 15 mV where agglomeration forms due to the lack of necessary charges for a repelling effect [49].…”