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

Introduction. Cellulose nanocrystals (CNCs) as attractive natural materials,have numerous applications in the biomedical field. Their unique biomechanicalcharacteristics, surface chemistry, low cost and sustainable naturemake them an engaging alternative to conventional materials and potentiatetheir use as progressive material. Therefore, it is critical to evaluate thecytocompatibility and immunomodulatory properties of nCNCs, which havenot been completely explored. The objective of this study was to examinea dose-dependent effect of native (n)CNCs on cytotoxicity and proliferativeactivity of human peripheral blood mononuclear cells (PBMNCs) in vitro.Methods. PBMNCs, obtained from the healthy blood donors, were cultivatedwith nCNCs. Cell viability was analyzed by flow cytometry assay, whileproliferative activity was determined by MTT, [3H]-thymidine uptake assayand 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 inducedby the highest concentration of nCNCs compared to control (p<0.05).Unexpectedly, the highest concentration of nCNCs increased the metabolicactivity of PHA-stimulated cells compared to control (p<0.05). In contrastto 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 followedby increased production of IL-2 (100 μg/ml) (p<0.001).Conclusion. The results suggest that non-cytotoxic concentrations of nCNCsmodulate the proliferative activity of human PBMNCs, a phenomenon whichhas not been published up to now and which is relevant for further studies.