Abstract
A finely ground fibrillated cellulose was fractionated
into separate size fractions. The characteristics of the
smallest size fractions were studied, and the toxicity to
humans was tested as part of a safety assessment.
Morphological studies performed with state-of-the-art
methods, such as scanning electron microscopy and atomic
force microscopy, showed that the fraction obtained
consisted of long thin fibrils but also larger fibril
agglomerates, and spherical particles were present. The
finest fraction did not show any sub-lethal effects as
assessed by RNA inhibition test in vitro, nor were there
any indications of genotoxicity as tested by the Ames
test in vitro. Systemic effects tested in vivo with the
nematode were also absent. No cytotoxic effects were seen
in the highest tolerated dose test in vitro, but some
indication of cytotoxicity was observed in the total
protein content test in vitro at the highest sample
concentration. The significance of this toxicity test
result should be addressed in relation to the other
toxicity tests, in which no toxicity was observed, with
special emphasis on the in vivo test. Given this, the
overall toxicity analyses support the conclusion that
nano-scale cellulose fibrils can be considered to be safe
towards humans. However, the reason for the positive
cytotoxicity test result and, in addition, the effect of
the biocide used in sample preservation on the toxicity
tests need to be clarified before generalizing these
results and declaring nanocellulose to be unambiguously
safe.
Original language | English |
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Pages (from-to) | 3871-3886 |
Journal | Cellulose |
Volume | 21 |
Issue number | 6 |
DOIs | |
Publication status | Published - 2014 |
MoE publication type | A1 Journal article-refereed |
Keywords
- cellulose
- nanocellulose
- fibrillated cellulose
- cytotoxicity
- genotoxicity