Cellular Responses Induced by Zinc in Zebra Mussel Haemocytes. Loss of DNA Integrity as a Cellular Mechanism to Evaluate the Suitability of Nanocellulose-Based Materials in Nanoremediation

Abstract

Zinc environmental levels are increasing due to human activities, posing a threat to ecosystems and human health. Therefore, new tools able to remediate Zn contamination in freshwater are highly recommended. Specimens of Dreissena polymorpha (zebra mussel) were exposed for 48 h and 7 days to a wide range of ZnCl2 nominal concentrations (1–10–50–100 mg/L), including those environmentally relevant. Cellulose-based nanosponges (CNS) were also tested to assess their safety and suitability for Zn removal from freshwater. Zebra mussels were exposed to 50 mg/L ZnCl2 alone or incubated with 1.25 g/L of CNS (2 h) and then removed by filtration. The effect of Zn decontamination induced by CNS has been verified by the acute toxicity bioassay Microtox®. DNA primary damage was investigated by the Comet assay; micronuclei frequency and nuclear morphological alterations were assessed by Cytome assay in mussels’ haemocytes. The results confirmed the genotoxic effect of ZnCl2 in zebra mussel haemocytes at 48 h and 7-day exposure time. Zinc concentrations were measured in CNS, suggesting that cellulose-based nanosponges were able to remove Zn(II) by reducing its levels in exposure waters and soft tissues of D. polymorpha in agreement with the observed restoration of genetic damage exerted by zinc exposure alone.

Eco-Friendly Engineered Nanomaterials Coupled with Filtering Fine-Mesh Net as a Promising Tool to Remediate Contaminated Freshwater Sludges: An Ecotoxicity Investigation

“…The effect of the decontamination of industrial canal sludge by CNS in combination with a fine-mesh net has been verified by an acute toxicity test on Aliivibrio fischeri performed as reported by Guidi et al [ 24 ] following the standard protocol UNI EN ISO (ISO 11348-3:2019) [ 30 ]. This test is based on the luminescence naturally emitted by the marine bacterium A. fischeri after its exposure to a toxic substance in the water matrix.…”

“…In this context, in recent years, we have reported the eco-design and synthesis of a new class of cross-linked nanocellulose (CNS), characterized by nanoporosity [ 18 , 19 ], which was safe and highly effective for water decontamination from heavy metals and organic molecules [ 20 , 21 , 22 ]. CNS were already proven to be safe for aquatic species by ecotoxicity assessment either with marine or freshwater species [ 10 , 23 , 24 ]. Specifically, in the framework of the Nanomaterials for Remediation of Environmental Matrices associated to Dewatering (NANOBOND) POR CReO FESR project, we have conceptualized the combination of CNS with a filtering fine-mesh net for the treatment of contaminated dredged sludge, in order to achieve the direct decontamination of outflowing water [ 16 ].…”

“…Herein, we report, for the first time, the results obtained at the laboratory scale by testing this approach on a real environmental matrix, characterized by the presence of different inorganic pollutants (mainly Zn, Ni, Cu, Fe, Ba, and As), with the final aim of both validating CNS decontamination efficiency in a simulated scenario and transferring the information obtained in previous single-contaminant exposure studies [ 10 , 24 ] to a laboratory scale prototype for freshwater sludge nanoremediation. Moreover, the coupling of both technologies (CNS and fine-mesh net) avoids the direct release of CNS into an aqueous matrix upon application for sludge treatment.…”

Cellulose for the Production of Air-Filtering Systems: A Critical Review

“…Combining the sustainability, biocompatibility, and biodegradability of cellulose to the lightweight open porous structures of aerogel systems is a great advantage for the production of promising materials [44]. Currently, research on cellulose and nanocellulosebased aerogels has gained large interest [45][46][47], and our research group has also widely contributed to the development of these porous materials by promoting the cross-linking of cellulose nanofibers for different purposes, including water decontamination [48][49][50][51][52], sensing [53,54], controlled drug-release [55], and more recently also for heterogeneous catalysis [56,57]. Made from gels, which result in interconnected nanostructures by converting the liquid phase in gas commonly though a freeze-drying process, aerogel systems present a large surface area and a low density [58,59].…”

Pd-Loaded Cellulose NanoSponge as a Heterogeneous Catalyst for Suzuki–Miyaura Coupling Reactions

“…The high porosity of the system derived from the freeze-drying process followed for converting the original hydrogel-like suspension of the two polymers into the resulting xerogel, with ice crystals acting as pores’ templates, while its chemical stability was guaranteed by the thermally induced (~100 °C) formation of amide bonds between the carboxyl groups of the oxidized nanocellulose and the amine groups of the polyamine. Further optimization of pristine formulations by addition of citric acid (CA) allowed the nanostructure to have higher mechanical resistance [ 25 ] and to better fix bPEI, improving the eco-safety [ 26 , 27 , 28 , 29 ] and the sustainability [ 30 ] of the material. More recently, the nanoporosity of the material was revealed by small-angle neutron scattering (SANS) investigation [ 31 ] and by FTIR-ATR analysis of the H-bond network, which evidenced water nanoconfinement in the nanostructure [ 32 , 33 ].…”