A bibliometric analysis of cellulose anti-fouling in marine environments

Marine biofouling poses significant challenges to maritime industries worldwide, affecting vessel performance, fuel efficiency, and environmental sustainability. These challenges demand innovative and sustainable solutions. In this review, the evolving landscape of cellulose-based materials for anti-fouling applications in marine environments is explored. Through a comprehensive bibliometric analysis, the current state of research is examined, highlighting key trends, emerging technologies, and geographical distributions. Cellulose, derived from renewable resources, offers a promising avenue for sustainable anti-fouling strategies due to its biodegradability, low toxicity, and resistance to microbial attachment. Recent advancements in cellulose-based membranes, coatings, and composites are discussed, showcasing their efficacy in mitigating biofouling while minimizing environmental impact. Opportunities for interdisciplinary collaboration and innovation are identified to drive the development of next-generation anti-fouling solutions. By harnessing the power of cellulose, progress towards cleaner, more sustainable oceans can be facilitated, fostering marine ecosystems and supporting global maritime industries.

Development of a yeast reporter gene assay to detect ligands of freshwater cladoceran Daphnia magna ultraspiracle, a homolog of vertebrate retinoid X receptors

Endocrine-disrupting chemicals (EDCs) often affect homeostatic regulation in living organisms by directly acting on nuclear receptors (NRs). Retinoid X receptors (RXRs), the most highly conserved members of the NR superfamily during evolution, function as partners to form heterodimers with other NRs, such as retinoic acid, thyroid hormone, and vitamin D3 receptors. RXRs also homodimerize and induce the expression of target genes upon binding with their natural ligand, 9-cis-retinoic acid (9cRA), and typical EDCs organotin compounds, such as tributyltin and triphenyltin. In the present study, we established a new yeast reporter gene assay (RGA) to detect the ligands of freshwater cladoceran Daphnia magna ultraspiracle (Dapma-USP), a homolog of vertebrate RXRs. D. magna has been used as a representative crustacean species for aquatic EDC assessments in the Organization for Economic Corporation and Development test guidelines. Dapma-USP was expressed along with the Drosophila melanogaster steroid receptor coactivator Taiman in yeast cells carrying the lacZ reporter plasmid. The RGA for detecting agonist activity of organotins and o-butylphenol was improved by use of mutant yeast strains lacking genes encoding cell wall mannoproteins and/or plasma membrane drug efflux pumps as hosts. We also showed that a number of other human RXR ligands, phenol and bisphenol A derivatives, and terpenoid compounds such as 9c-RA exhibited antagonist activity on Dapma-USP. Our newly established yeast-based RGA system is valuable as the first screening tool to detect ligand substances for Dapma-USP and for evaluating the evolutionary divergence of the ligand responses of RXR homologs between humans and D. magna.

Physiomimetic biocompatibility evaluation of directly printed degradable porous iron implants using various cell types

Additively manufactured (AM) degradable porous metallic biomaterials offer unique opportunities for satisfying the design requirements of an ideal bone substitute. Among the currently available biodegradable metals, iron has the highest elastic modulus, meaning that it would benefit the most from porous design. Given the successful preclinical applications of such biomaterials for the treatment of cardiovascular diseases, the moderate compatibility of AM porous iron with osteoblast-like cells, reported in earlier studies, has been surprising. This may be because, as opposed to static in vitro conditions, the biodegradation products of iron in vivo are transported away and excreted. To better mimic the in situ situations of biodegradable biomaterials after implantation, we compared the biodegradation behavior and cytocompatibility of AM porous iron under static conditions to the conditions with dynamic in situ-like fluid flow perfusion in a bioreactor. Furthermore, the compatibility of these scaffolds with four different cell types was evaluated to better understand the implications of these implants for the complex process of natural wound healing. These included endothelial cells, L929 fibroblasts, RAW264.7 macrophage-like cells, and osteoblastic MG-63 cells. The biodegradation rate of the scaffolds was significantly increased in the perfusion bioreactor as compared to static immersion. Under either condition, the compatibility with L929 cells was the best. Moreover, the compatibility with all the cell types was much enhanced under physiomimetic dynamic flow conditions as compared to static biodegradation. Our study highlights the importance of physiomimetic culture conditions and cell type selection when evaluating the cytocompatibility of degradable biomaterials in vitro. STATEMENT OF SIGNIFICANCE: Additively manufactured (AM) degradable porous metals offer unique opportunities for the treatment of large bony defects. Despite the successful preclinical applications of biodegradable iron in the cardiovascular field, the moderate compatibility of AM porous iron with osteoblast-like cells was reported. To better mimic the in vivo condition, we compared the biodegradation behavior and cytocompatibility of AM porous iron under static condition to dynamic perfusion. Furthermore, the compatibility of these scaffolds with various cell types was evaluated to better simulate the process of natural wound healing. Our study suggests that AM porous iron holds great promise for orthopedic applications, while also highlighting the importance of physio-mimetic culture conditions and cell type selection when evaluating the cytocompatibility of degradable biomaterials in vitro.

Molecular and Functional Characterization of Different BrainSphere Models for Use in Neurotoxicity Testing on Microelectrode Arrays

The currently accepted methods for neurotoxicity (NT) testing rely on animal studies. However, high costs and low testing throughput hinder their application for large numbers of chemicals. To overcome these limitations, in vitro methods are currently being developed based on human-induced pluripotent stem cells (hiPSC) that allow higher testing throughput at lower costs. We applied six different protocols to generate 3D BrainSphere models for acute NT evaluation. These include three different media for 2D neural induction and two media for subsequent 3D differentiation resulting in self-organized, organotypic neuron/astrocyte microtissues. All induction protocols yielded nearly 100% NESTIN-positive hiPSC-derived neural progenitor cells (hiNPCs), though with different gene expression profiles concerning regional patterning. Moreover, gene expression and immunocytochemistry analyses revealed that the choice of media determines neural differentiation patterns. On the functional level, BrainSpheres exhibited different levels of electrical activity on microelectrode arrays (MEA). Spike sorting allowed BrainSphere functional characterization with the mixed cultures consisting of GABAergic, glutamatergic, dopaminergic, serotonergic, and cholinergic neurons. A test method for acute NT testing, the human multi-neurotransmitter receptor (hMNR) assay, was proposed to apply such MEA-based spike sorting. These models are promising tools not only in toxicology but also for drug development and disease modeling.

Perinatal exposure to tributyltin affects feeding behavior and expression of hypothalamic neuropeptide Y in the paraventricular nucleus of adult mice

Organotins such as tributyltin chloride (TBT), are highly diffused environmental pollutants, which act as metabolism disrupting chemicals, i.e. may interfere with fat tissue differentiation, as well as with neuroendocrine circuits, thus impairing the control of energetic balance. We have previously demonstrated that adult exposure to TBT altered the expression of neuropeptides in the hypothalamus. In this study, we orally administered daily a solution containing oil, or TBT (0.25, 2.5, or 25 μg/kg body weight/day) to pregnant females from gestational day 8 until birth, and to their pups from day 0 until post-natal day 21. Our results showed that TBT exposure of female mice during gestation and of pups during lactation permanently altered the feeding efficiency of pups of both sexes and subcutaneous fat distribution in adult males. In addition, the neuropeptide Y system was affected at the level of the paraventricular nucleus, with a decrease in immunoreactivity in both sexes (significant in females for all TBT doses and in males only for intermediate TBT doses), while no effect was observed in other hypothalamic areas (arcuate, ventromedial and dorsomedial nuclei). Metabolic syndrome, as well as obesity and diabetes, which are significant health issues, are considered multifactorial diseases and may be caused by exposure to metabolic disruptors, both in adults and during perinatal life. In addition, our work indicates that TBT doses defined as the tolerably daily intake had a profound and sex-specific long-term effect.

High-content analysis of larval phenotypes for the screening of xenobiotic toxicity using Phallusia mammillata embryos

In recent years, pollution of surface waters with xenobiotic compounds became an issue of concern in society and has been the object of numerous studies. Most of these xenobiotic compounds are man-made molecules and some of them are qualified as endocrine disrupting chemicals (EDCs) when they interfere with hormones actions. Several studies have investigated the teratogenic impacts of EDCs in vertebrates (including marine vertebrates). However, the impact of such EDCs on marine invertebrates is much debated and still largely obscure. In addition, DNA-altering genotoxicants can induce embryonic malformations. The goal of this study is to develop a reliable and effective test for assessing toxicity of chemicals using embryos of the ascidian (Phallusia mammillata) in order to find phenotypic signatures associated with xenobiotics. We evaluated embryonic malformations with high-content analysis of larval phenotypes by scoring several quantitative and qualitative morphometric endpoints on a single image of Phallusia tadpole larvae with semi-automated image analysis. Using this approach we screened different classes of toxicants including genotoxicants, known or suspected EDCs and nuclear receptors (NRs) ligands. The screen presented here reveals a specific phenotypic signature for ligands of retinoic acid receptor/retinoid X receptor. Analysis of larval morphology combined with DNA staining revealed that embryos with DNA aberrations displayed severe malformations affecting multiple aspects of embryonic development. In contrast EDCs exposure induced no or little DNA aberrations and affected mainly neural development. Therefore the ascidian embryo/larval assay presented here can allow to distinguish the type of teratogenicity induced by different classes of toxicants.

Dynamic cytotoxicity of ZnO nanoparticles and bulk particles to Escherichia coli: A view from unfixed ZnO particle:Zn2+ ratio

ZnO nanoparticles (NPs) form binary mixtures of ZnO particles and released Zn²⁺ in the environment, and the quantitative contributions of these components to toxicity are still uncertain. Herein, quantitative contribution of ZnO particle and Zn²⁺ to cytotoxicity of ZnO NPs to Escherichia coli were determined during 48 h bioassay. The cytotoxicity and mechanisms of ZnO NPs were dynamic and affected by ionic strength, Fe³⁺, humic acid, and temperature due to the unfixed ZnO particle:Zn²⁺ ratio. ZnO NPs and ZnO bulk particles (BPs) had comparable cytotoxicity but distinct cytotoxic mechanisms. ZnO NPs cytotoxicity arises mainly from ZnO particles for 3 h and from Zn²⁺ afterwards (8-48 h). The cytotoxicity of ZnO BPs depends predominantly on ZnO particles for 12 h and on Zn²⁺ from 24 to 48 h. The cytotoxicity of ZnO NPs and BPs is partially attributable to Zn accumulation, and dependent on ZnO particle:Zn²⁺ ratio. The linear regressions of acute toxicity for ZnO NPs vs. BPs and Zn²⁺ yielded excellent r² (0.9994 and 0.9998) from literature data and good r² (≥ 0.714) under certain environmental factors, which can be applied to assess environmental risk of ZnO NPs. Furthermore, dynamic cytotoxicity and mechanisms should be seriously considered during the environmental risk assessment of ZnO NPs.

Initial Assessment of Variability of Responses to Toxicants in Donor-Specific Endothelial Colony Forming Cells

There is increased interest in using high throughput in vitro assays to characterize human population variability in response to toxicants and drugs. Utilizing primary human endothelial colony-forming cells (ECFCs) isolated from blood would be highly useful for this purpose because these cells are involved in neonatal and adult vasculogenesis. We characterized the cytotoxicity of four known toxic chemicals (NaAsO2, CdCl2, tributyltin [TBT], and menadione) and their four relatively nontoxic counterparts (Na2HAsO4, ZnCl2, SnCl2, and phytonadione, respectively) in eight ECFC clones representing four neonatal donors (2 male and 2 female donors, 2 clones per donor). ECFCs were exposed to 9 concentrations of each chemical in duplicate; cell viability was evaluated 48 h later using the fluorescent vital dye fluorescent dye 5-Carboxyfluorescein Diacetate (CFDA), yielding concentration-effect curves from each experiment. Technical (day-to-day) variability of the assay, assessed from three independent experiments, was low: p-values for the differences of results were 0.74 and 0.64 for the comparison of day 2 vs. day 1 and day 3 vs. day 1, respectively. The statistical analysis used to compare the entire concentration-effect curves has revealed significant differences in levels of cytotoxicity induced by the toxic and relatively nontoxic chemical counterparts, demonstrating that donor-specific ECFCs can clearly differentiate between these two groups of chemicals. Partitioning of the total variance in the nested design assessed the contributions of between-clone and between-donor variability for different levels of cytotoxicity. Individual ECFC clones demonstrated highly reproducible responses to the chemicals. The most toxic chemical was TBT, followed by NaAsO2, CdCl2, and Menadione. Nontoxic counterparts exhibited low cytotoxicity at the higher end of concentration ranges tested. Low variability was observed between ECFC clones obtained from the same donor or different donors for CdCl2, NaAsO2, and TBT, but for menadione, the between-donor variability was much greater than the between-clone variability. The low between-clone variability indicates that an ECFC clone may represent an individual donor in cell-based assays, although this finding must be confirmed using a larger number of donors. Such confirmation would demonstrate that an in vitro ECFC-based testing platform can be used to characterize the inter-individual variability of neonatal ECFCs exposed to drugs and/or environmental toxicants.

Prenatal exposure to oxidative phosphorylation xenobiotics and late-onset Parkinson disease

Late-onset Parkinson disease is a multifactorial and multietiological disorder, age being one of the factors implicated. Genetic and/or environmental factors, such as pesticides, can also be involved. Up to 80% of dopaminergic neurons of the substantia nigra are lost before motor features of the disorder begin to appear. In humans, these neurons are only formed a few weeks after fertilization. Therefore, prenatal exposure to pesticides or industrial chemicals during crucial steps of brain development might also alter their proliferation and differentiation. Oxidative phosphorylation is one of the metabolic pathways sensitive to environmental toxicants and it is crucial for neuronal differentiation. Many inhibitors of this biochemical pathway, frequently found as persistent organic pollutants, affect dopaminergic neurogenesis, promote the degeneration of these neurons and increase the risk of suffering late-onset Parkinson disease. Here, we discuss how an early, prenatal, exposure to these oxidative phosphorylation xenobiotics might trigger a late-onset, old age, Parkinson disease.

Organotins in Neuronal Damage, Brain Function, and Behavior: A Short Review

The consequences of exposure to environmental contaminants have shown significant effects on brain function and behavior in different experimental models. The endocrine-disrupting chemicals (EDC) present various classes of pollutants with potential neurotoxic actions, such as organotins (OTs). OTs have received special attention due to their toxic effects on the central nervous system, leading to abnormal mammalian neuroendocrine axis function. OTs are organometallic pollutants with a tin atom bound to one or more carbon atoms. OT exposure may occur through the food chain and/or contaminated water, since they have multiple applications in industry and agriculture. In addition, OTs have been used with few legal restrictions in the last decades, despite being highly toxic. In addition to their action as EDC, OTs can also cross the blood-brain barrier and show relevant neurotoxic effects, as observed in several animal model studies specifically involving the development of neurodegenerative processes, neuroinflammation, and oxidative stress. Thus, the aim of this short review is to summarize the toxic effects of the most common OT compounds, such as trimethyltin, tributyltin, triethyltin, and triphenyltin, on the brain with a focus on neuronal damage as a result of oxidative stress and neuroinflammation. We also aim to present evidence for the disruption of behavioral functions, neurotransmitters, and neuroendocrine pathways caused by OTs.

Deleterious effects of tributyltin on porcine vascular stem cells physiology

The vascular functional and structural integrity is essential for the maintenance of the whole organism and it has been demonstrated that different types of vascular progenitor cells resident in the vessel wall play an important role in this process. The purpose of the present research was to observe the effect of tributyltin (TBT), a risk factor for vascular disorders, on porcine Aortic Vascular Precursor Cells (pAVPCs) in term of cytotoxicity, gene expression profile, functionality and differentiation potential. We have demonstrated that pAVPCs morphology deeply changed following TBT treatment. After 48h a cytotoxic effect has been detected and Annexin binding assay demonstrated that TBT induced apoptosis. The transcriptional profile of characteristic pericyte markers has been altered: TBT 10nM substantially induced alpha-SMA, while, TBT 500nM determined a significant reduction of all pericyte markers. IL-6 protein detected in the medium of pAVPCs treated with TBT at both doses studied and with a dose response. TBT has interfered with normal pAVPC functionality preventing their ability to support a capillary-like network. In addition TBT has determined an increase of pAVPC adipogenic differentiation. In conclusion in the present paper we have demonstrated that TBT alters the vascular stem cells in terms of structure, functionality and differentiating capability, therefore effects of TBT in blood should be deeply explored to understand the potential vascular risk associated with the alteration of vascular stem cell physiology.

Toxicology of organic-inorganic hybrid molecules: bio-organometallics and its toxicology

Bio-organometallics is a research strategy of biology that uses organic-inorganic hybrid molecules. The molecules are expected to exhibit useful bioactivities based on the unique structure formed by interaction between the organic structure and intramolecular metal(s). However, studies on both biology and toxicology of organic-inorganic hybrid molecules have been incompletely performed. There can be two types of toxicological studies of bio-organometallics; one is evaluation of organic-inorganic hybrid molecules and the other is analysis of biological systems from the viewpoint of toxicology using organic-inorganic hybrid molecules. Our recent studies indicate that cytotoxicity of hybrid molecules containing a metal that is nontoxic in inorganic forms can be more toxic than that of hybrid molecules containing a metal that is toxic in inorganic forms when the structure of the ligand is the same. Additionally, it was revealed that organic-inorganic hybrid molecules are useful for analysis of biological systems important for understanding the toxicity of chemical compounds including heavy metals.