Cytotoxicity and physico-chemical evaluation of acetylated and pegylated cellulose nanocrystals

• Published in: Journal of nanoparticle research : an interdisciplinary forum for nanoscale science and technology Vol. 20; no. 8; pp. 1 - 12
• Main Authors: Montanheiro, Thaís L.A., Montagna, Larissa S., de Farias, Marcelo A., Magalhães, Jéssica A., Tada, Dayane B., Passador, Fabio R., Machado, João Paulo B., Lemes, Ana Paula
• Format: Journal Article
• Language: English
• Published: Dordrecht Springer Netherlands 01.08.2018; Springer Nature B.V
• Subjects: Acetic acid; Acetylation; Cell proliferation; Cellulose; Characterization and Evaluation of Materials; Chemistry and Materials Science; Crystals; Cytotoxicity; Fourier transforms; Hydrochloric acid; Hydrophilicity; Infrared spectroscopy; Inorganic Chemistry; Lasers; Light diffraction; Light scattering; Materials Science; Morphology; Nanocrystals; Nanotechnology; Optical Devices; Optics; Organic chemistry; Photon correlation spectroscopy; Photonics; Physical Chemistry; Polyethylene glycol; Reduction; Research Paper; Thermal stability; Thermogravimetric analysis; Toxicity; Transmission electron microscopy; Viability; X-ray diffraction; Zeta potential; Cell proliferation; Cellulose nanocrystal; Functionalization; Hydrophilicity; Nanoparticle; Pegylation; Acetylation
• ISSN: 1388-0764; 1572-896X
• DOI: 10.1007/s11051-018-4306-3

The high hydrophilicity of cellulose nanocrystals (CNC) may result in poor dispersion in some matrices and solvents. So in this work, two different methodologies were used to reduce the hydrophilicity of CNC. In the first methodology, CNC were acetylated (CNC-Ac) in a mixture of acetic and hydrochloric acid, and in the second methodology, polyethylene glycol (PEG) was adsorbed onto CNC surface (CNC-PEG) under stirring in aqueous solution. CNC obtained by both methods were characterized by transmission electron microscopy (TEM), infrared spectroscopy (FTIR), X-ray diffraction (XRD), dynamic light scattering (DLS), zeta potential, and thermogravimetric analysis (TGA). Images of TEM showed that the intrinsic morphology of cellulose was preserved after both treatments. FTIR confirmed acetylation reaction by the presence of a new band at 1732 cm −1 (acetate groups) and the consumption of OH groups. XRD showed a reduction in the crystallinity index for both applied methodologies. DLS showed reduced stability in water for CNC-Ac and CNC-PEG. Values of zeta potential changed after acetylation, from − 45 mV (CNC) to − 1 mV (CNC-Ac), and after adsorption of PEG, to − 26.7 mV (CNC-PEG). TGA showed a reduction in the thermal stability after both treatments and a change in the main degradation behavior for CNC-PEG. MTT assays showed that both proposed functionalizations induce cell proliferation, being even more evident for acetylation because, in addition to viability increase with time, it increased with the sample concentration.