Cellulose nanocrystals induce a dose-dependent effect on cytotoxicity and proliferative activity of human peripheral blood mononuclear cells

Abstract

Introduction. Cellulose nanocrystals (CNCs) as attractive natural materials,
have numerous applications in the biomedical field. Their unique biomechanical
characteristics, surface chemistry, low cost and sustainable nature
make them an engaging alternative to conventional materials and potentiate
their use as progressive material. Therefore, it is critical to evaluate the
cytocompatibility and immunomodulatory properties of nCNCs, which have
not been completely explored. The objective of this study was to examine
a dose-dependent effect of native (n)CNCs on cytotoxicity and proliferative
activity of human peripheral blood mononuclear cells (PBMNCs) in vitro.
Methods. PBMNCs, obtained from the healthy blood donors, were cultivated
with nCNCs. Cell viability was analyzed by flow cytometry assay, while
proliferative activity was determined by MTT, [3H]-thymidine uptake assay
and detection of IL-2 production.
Results. The cytotoxicity results suggested that no concentration of nCNCs
(50-400 μg/ml) affected necrosis of PBMNCs, whereas apoptosis was induced
by the highest concentration of nCNCs compared to control (p<0.05).
Unexpectedly, the highest concentration of nCNCs increased the metabolic
activity of PHA-stimulated cells compared to control (p<0.05). In contrast
to these findings, lower concentrations of nCNCs (50 μg/ml and 100 μg/ml)
stimulated proliferation of PBMNCs (p<0.05 and p<0.001). It was followed
by increased production of IL-2 (100 μg/ml) (p<0.001).
Conclusion. The results suggest that non-cytotoxic concentrations of nCNCs
modulate the proliferative activity of human PBMNCs, a phenomenon which
has not been published up to now and which is relevant for further studies.