Genotoxicity of Three Micro/Nanocelluloses with Different Physicochemical Characteristics in MG-63 and V79 Cells

Abstract

(1) Background: Nanocellulose is an innovative engineered nanomaterial with an enormous potential for use in a wide array of industrial and biomedical applications and with fast growing economic value. The expanding production of nanocellulose is leading to an increased human exposure, raising concerns about their potential health effects. This study was aimed at assessing the potential toxic and genotoxic effects of different nanocelluloses in two mammalian cell lines; (2) Methods: Two micro/nanocelluloses, produced with a TEMPO oxidation pre-treatment (CNFs) and an enzymatic pre-treatment (CMFs), and cellulose nanocrystals (CNCs) were tested in osteoblastic-like human cells (MG-63) and Chinese hamster lung fibroblasts (V79) using the MTT and clonogenic assays to analyse cytotoxicity, and the micronucleus assay to test genotoxicity; (3) Results: cytotoxicity was observed by the clonogenic assay in V79 cells, particularly for CNCs, but not by the MTT assay; CNF induced micronuclei in both cell lines and nucleoplasmic bridges in MG-63 cells; CMF and CNC induced micronuclei and nucleoplasmic bridges in MG-63 cells, but not in V79 cells; (4) Conclusions: All nanocelluloses revealed cytotoxicity and genotoxicity, although at different concentrations, that may be related to their physicochemical differences and availability for cell uptake, and to differences in the DNA damage response of the cell model.

Assessing the Genotoxicity of Cellulose Nanomaterials in a Co-Culture of Human Lung Epithelial Cells and Monocyte-Derived Macrophages

“…The results from the micronucleus assay showed no effect on CBPI and no significant increase in the frequency of micronucleated cells after 48 h exposure to each CMNM, suggesting no cytotoxic or genotoxic effect, respectively. It is generally assumed that CMNMs are not cytotoxic (reviewed in [ 24 ]), although there are studies indicating some cytotoxicity with longer exposure times [ 29 ]. In a previous study using the same concentration range of these three CMNMs, none induced a significant cytotoxic effect in A549 cells as compared to the controls, after a 24 h exposure period [ 47 ].…”

“…In fact, in previous studies, only the two lowest concentrations tested of the same CNF-TEMPO and CMF-ENZ (1.5 and 3 µg/cm 2 ) caused a significant increase in micronuclei frequencies in osteoblastic-like human cells (MG-63 cells). In addition, chinese hamster lung fibroblasts (V79 cells) displayed an increased frequency of micronuclei after treatment with 3 and 12.5 µg/cm 2 of CNF-TEMPO, being much more resistant to the genotoxic effects of CNMNs than MG-63 cells [ 29 ]. The general absence of genotoxicity of CMNMs, particularly at higher concentrations, may be related to their entanglement and aggregation, as already demonstrated [ 47 ].…”

“…Some studies showed a low internalization ability in cells, and no strong evidence of significant cytotoxicity or genotoxicity [ 24 ]. However, some contradictory results have also been reported, pointing to in vivo [ 25 , 26 ] and in vitro [ 21 , 27 , 28 ] genotoxicity of some CNF, and inflammatory effects of several CNC in macrophages that ranged from mild to severe, according to their functionalization [ 29 , 30 , 31 , 32 ].…”