Table 5.
Cytotoxicity evaluations in in vitro studies induced by CNF- and CNF-based materials.
| Material | Cellulose Source | Toxicological Experiment |
Cells Lines |
Toxicological Results | Results and Possible Application |
Ref. |
|---|---|---|---|---|---|---|
| CNF | ||||||
| CNF | Bleached dissolving pulp Norway spruce (Picea bies) | MTT assay [3H]-thymidine uptake assay |
L929; Thymocytes PBMNCs |
CNFs were not cytotoxic; CNC has non-inflammatory and on-immunogenic properties. |
Implantable biomaterials TE | [184] |
| CNF |
Pinus radiata pulp |
LDH assay MTT assay |
HEK NHDF |
No toxic effect for keratinocytes and fibroblasts; Non-immunotoxic. |
Wound dressings | [208] |
| CNF CNC |
Wood pulp | TB assay | A549 | CNF caused a significant decrease in cell viability, at 72 h; Decrease in GSH levels after exposure to CNF. |
CNC toxicity | [185] |
| U-NFC A-NFC C-NFC |
Never-dried bleached sulfite softwood dissolving pulp | AB assay LDH assays |
HDF MRC-5 THP-1 |
No cytotoxicity for treated NFC; HDF and MRC-5 cells: the metabolic activity of the treated cells was comparable to that of the negative control; THP-1 cells: a higher metabolic activity of the NFC-treated; U-CNF has an inflammatory response, which was suppressed when surface charges were introduced on the CNFs. |
Toxicity impacts on dermal, lung, and macrophage cells | [187] |
| CNF | Bleached Eucalyptus Globulus kraft pulp |
MTT assay | A549 THP-1 |
Cytotoxic effect at the highest dose tested; Genotoxic effects in A549 cells in the co-cultures; No oxidative DNA damages. |
TE | [209] |
| CNF | Curauá fibers (Ananas erectifolius L. B. Smith) | Cytotoxicity assays ISO 10993-5 |
Vero | CNF shows no cytotoxicity and suitable biocompatibility; The morphology and basic functions of the cells are not affected by the direct contact with the tested materials. |
Scaffold TE |
[186] |
| CNF | Softwood bleached kraft fiber | LDH assay |
Caco-2, HT-29MTX Raji B |
Minimal or no cytotoxicity in a cellular model of the intestinal epithelium (for CNC-25 at 0.75% and 1.5% w/w, as well as for CNF-50 at 0.75% w/w). | Biocompatible material | [210] |
| CNF | Banana peel bran | MTT assay | Caco-2 | CNF conc. < 500 mg/mL are not cytotoxic to Caco-2 cells; Viability of Caco-2 decreased with increasing CNF conc. |
Biocompatible material | [211] |
| U-NFC A-NFC C-NFC P-NFC S-NFC |
Never-dried bleached sulfite softwood dissolving pulp | Resazurin Assay | Caco-2 | None of the NFCs inducing cytotoxic effects in the intestinal cells; The differences in physics-chemical properties of the studied NFCs were not reflected in the Caco-2 response in terms of metabolic activity and cell membrane integrity. |
Drug release in gastrointestinal tract (GIT) | [188] |
| U-NFC C-NFC H-NFC P-NFC S-NFC |
Never-dried bleached sulfite softwood dissolving pulp | MTS Assay | BEAS-2B | No cytotoxicity for the highest tested dose (500 μg/mL) for any of the NFCs; None of the NFCs induced genotoxic effects; All samples were able to increase intracellular formation of ROS. |
In vitro toxicity of NFCs | [189] |
| c-CNF cys-CNF |
Never-dried bleached sulfite softwood dissolving pulp | PB assay | hDF | cys-CNF did not induce toxic effects on hDF when tested at a concentration up to 0.5 mg/mL, nor did the starting material c-NF cys-CNF presented a dual action in vitro: inhibition of metalloproteinase and radical scavenging activity. |
Wound dressing | [190] |
| CNF in nanocomposites | ||||||
| CNF L-CNF CNC L-CNC |
Dissolving pulp | AB assay | A549 THP-1 |
Cytotoxic and inflammatory responses were dependent on type, size, and hydrophobicity Low or inexistent toxicity of all CNMs in A549 cells Dose-dependent cytotoxic and inflammatory responses in THP-1 cells. |
TE | [199] |
| CNF /GEL/ApA | Bleached birch pulp | MTT assay | MSCs | CNFs and CNF-COOHs have no cytotoxicity; CNF-COOH-ApA cells expressed a low level of stress, visible through lower cell density and the cell inclusions. |
Bone TE | [130] |
| NFC hydrogels crosslinked with Ca2+ | Bleached sulfite softwood pulp | AB assay | hDF | Cell viability about 78% indicates no toxic effects. No inflammatory response of blood-derived mononuclear cells was observed in relation to the cytokines secretion. |
Wound healing | [27] |
| TEMPO-CNF hydrogel |
Bleached birch kraft pulp | MTT assay | hDF | Nontoxicity effect and great hDF cells viability. | Wound healing | [172] |
| NFC/QCRs nanocomposites | Brown algae | MTT assay | L929 | Cells viability is higher than 80% (for 5 to 1000 μg/mL CNFs/QCRs), indicating that there is no cytotoxicity. | Wound healing | [119] |
Abbreviations: PBMNC—Human peripheral blood mononuclear cells; HEK—Human epidermal keratinocytes; NHDF—Normal human dermal fibroblasts; A549—Human lung alveolar epithelial cells; HDF—Human dermal fibroblasts; MRC-5—Human lung fibroblast cell line; THP-1—Human monocytic leukemia cell line; A549—Human alveolar epithelial cell line; Caco-2—Human epithelial colorectal adenocarcinoma cells; BEAS-2B—Transformed human bronchial epithelial cells; hDF—Adult human dermal fibroblasts; MSCs—Mesenchymal stem cells; L929—Mouse fibroblast cells; GSH—Levels of glutathione (marker of oxidative stress); GIT—Gastrointestinal tract; MTT—Methylthiazolyldiphenyl-tetrazolium bromide; AB assay—Alamar blue assay; MTS assay—CellTiter-Glo luminescent cell viability assay; PB assay—Presto blue assay; AB assay—Alamar blue cell viability assay; U-NFC—Unmodified NFC; A-NFC—Carboxymethylated-NFC; C-NFC—Hydroxypropyltrimethylammonium-NFC; P-NFC—Phosphorylated NFC; S-NFC—Sulfoethylated NFC; C-NFC—Carboxymethylated-NFC; H-NFC—Hydroxypropyltrimethylammonium-NFC; c-CNF—Carboxylated CNF; cys-CNF—Cysteine-functionalized CNF; L-CNC—Lignin-coated-CNC; L-CNF—Lignin-coated-CNF.