Probing inhibitory effects of nanocrystalline cellulose: inhibition versus surface charge (original) (raw)
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ACS Applied Materials & Interfaces, 2010
Probing of cellular uptake and cytotoxicity was conducted for two fluorescent cellulose nanocrystals (CNCs): CNCfluorescein isothiocyanate (FITC) and newly synthesized CNC-rhodamine B isothiocyanate (RBITC). The positively charged CNC-RBITC was uptaken by human embryonic kidney 293 (HEK 293) and Spodoptera frugiperda (Sf9) cells without affecting the cell membrane integrity. The cell viability assay and cell-based impedance spectroscopy revealed no noticeably cytotoxic effect of the CNC-RBITC conjugate. However, no significant internalization of negatively charged CNC-FITC was observed at physiological pH. Indeed, the effector cells were surrounded by CNC-FITC, leading to eventual cell rupture. As the surface charge of CNC played an important role in cellular uptake and cytotoxicity, facile surface functionalization together with observed noncytotoxicity rendered modified CNC as a promising candidate for bioimaging and drug delivery systems.
Colloids and surfaces. B, Biointerfaces, 2014
A controlled preparation of cellulose nanocrystals of different sizes and shapes has been carried out by acid hydrolysis of microcrystalline cellulose. The size-and concentration-dependent toxicity effects of the resulting cellulose nanocrystals were evaluated against two different cell lines, NIH3T3 murine embryo fibroblasts and HCT116 colon adenocarcinoma. It could serve as a therapeutic platform for cancer treatment.
ACS Sustainable Chemistry & Engineering, 2014
The use of cellulose as building blocks for the development of novel functional materials is rapidly growing. Cellulose nanocrystals (CNC), with advantageous chemical and mechanical properties, have gained prominence in a number of applications, such as in nanofillers in polymer composites, building materials, cosmetics, food, and the drug industry. Therefore, it becomes critical to evaluate the potential health effects associated with CNC exposures. The objective of this study was to compare pulmonary outcomes caused by exposure of C57BL/6 mice to two different processed forms of CNC derived from wood, i.e., CNCS (10 wt %; gel/suspension) and CNCP (powder), and compare to asbestos induced responses. Pharyngeal aspiration with CNCS and CNCP was found to facilitate innate inflammatory response assessed by an increase in leukocytes and eosinophils recovered by bronchoalveolar lavage (BAL). Biomarkers of tissue damage were elevated to a higher extent in mice exposed to CNCP. Compared to CNCP, CNCS caused a significant increase in the accumulation of oxidatively modified proteins. The up-regulation of inflammatory cytokines was higher in the lungs after CNCS treatments. Most importantly, CNCP materials were significantly longer than CNCS. Taken together, our data suggests that particle morphology and nanosize dimensions of CNCs, regardless of the same source, may be critical factors affecting the type of innate immune inflammatory responses. Because various processes have been developed for producing highly sophisticated nanocellulose materials, detailed assessment of specific health outcomes with respect to their physical−structural−chemical properties is highly warranted.
An ecotoxicological characterization of nanocrystalline cellulose (NCC)
Nanotoxicology, 2010
The pulp and paper industry in Canada is developing technology for the production and use of nanocrystalline cellulose (NCC). A key component of the developmental work is an assessment of potential environmental risks. Towards this goal, NCC samples as well as carboxyl methyl cellulose (CMC), a surrogate of the parent cellulosic material, were subjected to an ecotoxicological evaluation. This involved toxicity tests with rainbow trout hepatocytes and nine aquatic species. The hepatocytes were most sensitive (EC20s between 10 and 200 mg/L) to NCC, although neither NCC nor CMC caused genotoxicity. In tests with the nine species, NCC affected (IC25) the reproduction of the fathead minnow at 0.29 g/L, but no other effects on endpoints such as survival and growth occurred in the other species at concentrations below 1 g/L, which was comparable to CMC. Based on this ecotoxicological characterization, NCC was found to have low toxicity potential and environmental risk.
Role of Surface Chemistry in the In Vitro Lung Response to Nanofibrillated Cellulose
Nanomaterials, 2021
Wood-derived nanofibrillated cellulose (NFC) has emerged as a sustainable material with a wide range of applications and increasing presence in the market. Surface charges are introduced during the preparation of NFC to facilitate the defibrillation process, which may also alter the toxicological properties of NFC. In the present study, we examined the in vitro toxicity of NFCs with five surface chemistries: nonfunctionalized, carboxymethylated, phosphorylated, sulfoethylated, and hydroxypropyltrimethylammonium-substituted. The NFC samples were characterized for surface functional group density, surface charge, and fiber morphology. Fibril aggregates predominated in the nonfunctionalized NFC, while individual nanofibrils were observed in the functionalized NFCs. Differences in surface group density among the functionalized NFCs were reflected in the fiber thickness of these samples. In human bronchial epithelial (BEAS-2B) cells, all NFCs showed low cytotoxicity (CellTiter-GloVR lumi...
Macromolecular Materials and Engineering, 2019
One of the most recent robust global trends in vogue is the extraction of nanostructured materials from cellulose to employ their improved properties to develop innovative high-value biocomposite materials with new advanced functionalities. [7-10] Cellulose, a ubiquitous biomaterial, is considered an inexhaustible source of feedstock that matches the worldwide trend for green and biocompatible products, [11-13] being a very attractive source of materials because of its availability, biodegradability, and renewable origin. Nowadays, cellulose represents about 50% of natural biomass, being biosynthesized from lower to higher plants, sea animals, bacteria, and fungi, with a yearly production estimated to be around 10 tons. [11,14-16] Due to the large number of commercial application possibilities and other miscellaneous applications, the cellulose market is related to their efficient fabrication at affordable quantity and quality. In 2015, one report from Market-Intell LCC stated that the worldwide market for products incorporating cellulosic nanotechnology in 2014 was around 250million,andwasexpectedtoreachavalueof250 million, and was expected to reach a value of 250million,andwasexpectedtoreachavalueof3 trillion in 2019. [17] Currently, there are several commercial entities producing nanocellulose crystallites at capacities beyond plant scale, that is, CelluForce, Canada (production capacity of 1000 kg day −1), American Process, United States (500 kg day −1), Holmen (Melodea), Sweden (100 kg day −1), Alberta Innovates, Canada (20 kg day −1) and another with lower capacity (US Forest Products Lab, Blue Goose Biorefineries, India Council for Agricultural Research, and FPInnovations). These promising characteristics go along with the environmental awareness and demand for sustainable plant-based raw materials for a rational and eco-friendly economy, also contributing to diminishing adverse environmental impacts and the reuse of industrial waste. [1] The submicromaterials market, which encompasses microfibrillated cellulose and cellulose nanofibrils (CNF), is also expanding, with consolidated companies like Paperlogic (2000 kg day −1) and the University of Maine, United States (1000 kg day −1). [17] Cellulosic fibers can be subjected to acid hydrolysis and produce cellulose nanocrystals (CNCs) or cellulose nanowhiskers: needle-shaped nanometric or rod like particles. The use of a diversified CNC extraction process or other manufacturing steps led to different properties, such as average diameter (D), length (L), aspect ratio (L/D), crystallinity index, and thermal stability. [1,9,18-25] In addition, numerous research facilities are producing nanocellulose, and several new labs and pilot plants have been announced. [17] Cellulose monocrystals impart an attractive arrangement of biophysicochemical characteristics, such as low toxicity, stiffness, lightweight, low thermal expansion, gas impermeability, thermal stability, hydrophilic absorbent, adaptable surface chemistry, and remarkable mechanical and optical properties, like high tensile strength and elasticity, optical transparency, and anisotropic behavior. In addition, CNCs are capable to selforganize and produce materials with improved appearance, thermal properties, and barrier performances. [13,26-29] These properties can be exploited in numerous fields, including the pharmaceutical industry and regenerative medicine, [13] with the development of new formulations and drug delivery systems, such as emulsions, [30-34] liposomes, [35] aerogels and hydrogels, [36-40] DNA hybrid nanomaterials, [41] polymeric films, [42-46] adhesives and coatings, [47] packaging applications, [48-52] tissue Bruna Luíza Pelegrini is a master in pharmaceutical sciences from the University of Maringá (UEM, Brazil). She has developed research at the Instituit des Molécules et Matériaux du Maine
NanoImpact, 2019
The characterization of cellulose-based nanomaterial (CNM) suspensions in environmental and biological media is impaired because of their high carbon content and anisotropic shape, thus making it difficult to derive structure activity relationships (SAR) in toxicological studies. Here, a standardized method for the dispersion preparation and characterization of cellulose nanofibrils (CNF) and nanocrystals (CNC) in biological and environmental media was developed. Specifically, electron microscopy was utilized and allowed to specify optimum practices for efficiently suspending CNF and CNC in water and cell culture medium. Furthermore, a technique for measuring the in vitro particle kinetics of CNF and CNC suspended in cell culture medium utilizing fluorescently tagged materials was developed to assess the delivery rate of such CNM at the bottom of the well. Interestingly, CNF were shown to settle and create a loosely packed layer at the bottom of cell culture wells within a few hours. On the contrary, CNC settled gradually at a significantly slower rate, highlighting the discordance between administered and delivered mass dose. This work is both novel and urgent in the field of environmental health and safety as it introduces well-defined techniques for the dispersion and characterization of emerging, cellulose-based engineered nanomaterials. It also provides useful insights to the in vitro behavior of suspended anisotropic nanomaterials in general, which should enable dosimetry and comparison of toxicological data across laboratories as well as promote the safe and sustainable use of nanotechnology.
Analysis of cellulose nanocrystals (CNCs) with flow cytometry
Cellulose, 2018
Cellulose nanocrystals (CNCs) were prepared from kraft pulps of eucalyptus, birch, and softwood. The different kraft pulps were hydrolyzed using strong sulfuric acid in order to obtain colloidally stable CNCs. The CNCs were studied using flow cytometry (FCM). The light scattering properties of the CNCs in side direction and forward direction were documented. The use of a selective staining agent in combination with FCM analysis enabled detection of the hydrophobic particle populations within the CNC suspensions. The hydrophobic particles were seen clearly in the CNCs from the eucalyptus and birch kraft pulps, but not in the CNCs from softwood pulp. These particles were shown to be linked with the content of lipophilic extractives, especially sterols, present in the kraft pulps. From this fact, it was concluded that FCM analyses offer useful information about the properties of CNCs in suspension. It was also concluded that the content of lipophilic extractives in different raw materials should be determined and considered prior to CNC production. Pre-extraction steps might be needed in order to produce high-quality CNCs from various raw materials, even from kraft pulps.
Biomolecules, 2019
Wood-based cellulose nanofibrils (CNF) offer an excellent scaffold for drug-delivery formulation development. However, toxicity and haemocompatibility of the drug carrier is always an important issue. In this study, toxicity-related issues of CNF were addressed. Different doses of CNF were orally administered to Drosophila and different tests like the developmental cycle, trypan blue exclusion assay, larva crawling assay, thermal sensitivity assay, cold sensitivity assay, larval light preference test, climbing behaviour, nitroblue tetrazolium (NBT) reduction assay, adult phenotype, and adult weight were conducted to observe the impact on its development and behaviour. A haemocompatibility assay was done on the blood taken from healthy Wistar rats. In Drosophila, the abnormalities in larval development and behaviour were observed in the behavioural assays. However, the cytotoxic effect could not be confirmed by the gut staining and level of reactive oxygen species. The larvae develop...