Abstract
Wood-derived nanofibrillated cellulose (NFC) has emerged as a sustainable material with a wide range of applications and increasing presence in the market. Surface charges are introduced during the preparation of NFC to facilitate the defibrillation process, which may also alter the toxicological properties of NFC. In the present study, we examined the in vitro toxicity of NFCs with five surface chemistries: nonfunctionalized, carboxymethylated, phosphorylated, sulfoethylated, and hydroxypropyltrimethylammonium-substituted. The NFC samples were characterized for surface functional group density, surface charge, and fiber morphology. Fibril aggregates predominated in the nonfunctionalized NFC, while individual nanofibrils were observed in the functionalized NFCs. Differences in surface group density among the functionalized NFCs were reflected in the fiber thickness of these samples. In human bronchial epithelial (BEAS-2B) cells, all NFCs showed low cytotoxicity (CellTiter-GloVR luminescent cell viability assay) which never exceeded 10% at any exposure time. None of the NFCs induced genotoxic effects, as evaluated by the alkaline comet assay and the cytokinesis-block micronucleus assay. The nonfunctionalized and carboxymethylated NFCs were able to increase intracellular reactive oxygen species (ROS) formation (chloromethyl derivative of 2′,7′-dichlorodihydrofluorescein diacetate assay). However, ROS induction did not result in increased DNA or chromosome damage.
Highlights
Cellulose nanofibers have emerged as sustainable and environmentally friendly materials with a wide range of industrial and medical applications [1]
Wood pulp fibers are processed with chemical and enzymatic pretreatments to facilitate the structural deconstruction of the fibers into two main types of nanocelluloses: nanofibrillated cellulose (NFC) and cellulose nanocrystal [2,3]
We investigated the role of surface chemistry in modulating the in vitro toxic potential of NFC, by analyzing the ability of the materials to induce cytotoxic effects, the formation of reactive oxygen species (ROS), and DNA and chromosomal damage in human bronchial epithelial BEAS-2B cells
Summary
Cellulose nanofibers have emerged as sustainable and environmentally friendly materials with a wide range of industrial and medical applications [1]. The conflicting results may partly be due to variation among NFCs because of different factors, e.g., cellulose source, mechanical fibrillation procedure, or pretreatments [21], which can modify the material properties It is well-recognized that the physicochemical features of nanomaterials may affect their toxicity [16,22,23], surface chemistry being one of the most relevant ones [18]. We investigated the role of surface chemistry in modulating the in vitro toxic potential of NFC, by analyzing the ability of the materials to induce cytotoxic effects, the formation of reactive oxygen species (ROS), and DNA and chromosomal damage in human bronchial epithelial BEAS-2B cells.
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
