Toxicity in vitro and in Zebrafish Embryonic Development of Gold Nanoparticles Biosynthesized Using Cystoseira Macroalgae Extracts

Zebrafish Insights into Nanomaterial Toxicity: A Focused Exploration on Metallic, Metal Oxide, Semiconductor, and Mixed-Metal Nanoparticles

Nanomaterials are widely used in various fields, and ongoing research is focused on developing safe and sustainable nanomaterials. Using zebrafish as a model organism for studying the potentially toxic effects of nanomaterials highlights the importance of developing safe and sustainable nanomaterials. Studies conducted on nanomaterials and their toxicity and potential risks to human and environmental health are vital in biomedical sciences. In the present review, we discuss the potential toxicity of nanomaterials (inorganic and organic) and exposure risks based on size, shape, and concentration. The review further explores various types of nanomaterials and their impacts on zebrafish at different levels, indicating that exposure to nanomaterials can lead to developmental defects, changes in gene expressions, and various toxicities. The review also covers the importance of considering natural organic matter and chorion membranes in standardized nanotoxicity testing. While some nanomaterials are biologically compatible, metal and semiconductor nanomaterials that enter the water environment can increase toxicity to aquatic creatures and can potentially accumulate in the human body. Further investigations are necessary to assess the safety of nanomaterials and their impacts on the environment and human health.

Cartilage-inspired self-assembly glycopeptide hydrogels for cartilage regeneration via ROS scavenging

Cartilage injury represents a frequent dilemma in clinical practice owing to its inherently limited self-renewal capacity. Biomimetic strategy-based engineered biomaterial, capable of coordinated regulation for cellular and microenvironmental crosstalk, provides an adequate avenue to boost cartilage regeneration. The level of oxidative stress in microenvironments is verified to be vital for tissue regeneration, yet it is often overlooked in engineered biomaterials for cartilage regeneration. Herein, inspired by natural cartilage architecture, a fibril-network glycopeptide hydrogel (Nap-FFGRGD@FU), composed of marine-derived polysaccharide fucoidan (FU) and naphthalenephenylalanine-phenylalanine-glycine-arginine-glycine-aspartic peptide (Nap-FFGRGD), was presented through a simple supramolecular self-assembly approach. The Nap-FFGRGD@FU hydrogels exhibit a native cartilage-like architecture, characterized by interwoven collagen fibers and attached proteoglycans. Beyond structural simulation, fucoidan-exerted robust biological effects and Arg-Gly-Asp (RGD) sequence-provided cell attachment sites realized functional reinforcement, synergistically promoted extracellular matrix (ECM) production and reactive oxygen species (ROS) elimination, thus contributing to chondrocytes-ECM harmony. In vitro co-culture with glycopeptide hydrogels not only facilitated cartilage ECM anabolic metabolism but also scavenged ROS accumulation in chondrocytes. Mechanistically, the chondro-protective effects induced by glycopeptide hydrogels rely on the activation of endogenous antioxidant pathways associated with nuclear factor erythroid 2-related factor 2 (NRF2). In vivo implantation of glycopeptide hydrogels successfully improved the de novo cartilage generation by 1.65-fold, concomitant with coordinately restructured subchondral bone structure. Collectively, our ingeniously crafted bionic glycopeptide hydrogels simultaneously rewired chondrocytes' function by augmenting anabolic metabolism and rebuilt ECM microenvironment via preserving redox equilibrium, holding great potential for cartilage tissue engineering.

Toxicity evaluation of zinc oxide nanoparticles green synthesized using papaya extract in zebrafish

In green synthesis of zinc oxide nanoparticles (ZnO NPs), the use of papaya extract as a capping and reducing agent shows promise for potential applications of these particles in biomedicine. However, toxicity evaluation is necessary to ensure the safety of humans and the environment. The zebrafish model is used to assess toxicity with embryo developmental observation as it is a rapid, simple method for screening of toxicity. The objective of the present study was to assess the toxicological characteristics of ZnO NPs produced from papaya extract using a zebrafish model. The preparation of plant extracts from papaya using two solvents (water and methanol) and characterization of bioactive compounds in the extracts were reported. ZnO NPs were synthesized from both plant extracts and characterized with scanning electron microscopy, X-ray diffraction and Fourier transform infrared spectroscopy. Toxicity evaluation was conducted on zebrafish embryos for 96 h. ZnO NPs synthesized from aqueous and methanol extracts had mean crystallite diameters of 13 and 12 nm, respectively. Mortality, hatching rate and malformation of zebrafish embryos were assessed at different concentrations of ZnO NPs. Both NPs showed high mortality rates at high concentrations, with 100 (aqueous) and 20 mg/l (methanol extract) being lethal for all embryos. Concentrations <10 mg/l for both synthesized ZnO NPs had similar results to the negative control, indicating a safe dosage for embryos. The hatching rate and malformation were also affected, with higher concentrations of NPs causing a delayed hatching rate and malformation in pericardial and yolk sac edema. Whole embryo mRNA expression of immune-associated genes, including IL-1 and -10 and TNF-α, was upregulated following lethal concentration 50 (LC50) ZnO NP exposure. ZnO NPs synthesized from papaya extract (both in aqueous and methanol environments) had a dose- and time-dependent embryonic toxicity effect. Hence, the present study demonstrated initial toxicity screening of ZnO NPs synthesized from plant extract.

New investigation of anti-inflammatory activity of Polycladia crinita and biosynthesized selenium nanoparticles: isolation and characterization

BACKGROUND

Marine macroalgae have gained interest recently, mostly due to their bioactive components. Polycladia crinita is an example of marine macroalgae from the Phaeophyceae class, also known as brown algae. They are characterized by a variety of bioactive compounds with valuable medical applications. The prevalence of such naturally active marine resources has made macroalgae-mediated manufacturing of nanoparticles an appealing strategy. In the present study, we aimed to evaluate the antioxidant and anti-inflammatory features of an aqueous extract of Polycladia crinita and biosynthesized P. crinita selenium nanoparticles (PCSeNPs) via a carrageenan-induced rat paw edema model. The synthesized PCSeNPs were fully characterized by UV-visible spectroscopy, FTIR, XRD, and EDX analyses.

RESULTS

FTIR analysis of Polycladia crinita extract showed several sharp absorption peaks at 3435.2, 1423.5, and 876.4 cm-1 which represent O-H, C=O and C=C groups. Moreover, the most frequent functional groups identified in P. crinita aqueous extract that are responsible for producing SeNPs are the -NH2-, -C=O-, and -SH- groups. The EDX spectrum analysis revealed that the high percentages of Se and O, 1.09 ± 0.13 and 36.62 ± 0.60%, respectively, confirmed the formation of SeNPs. The percentages of inhibition of the edema in pretreated groups with doses of 25 and 50 mg/kg, i.p., of PCSeNPs were 62.78% and 77.24%, respectively. Furthermore, the pretreated groups with 25, 50 mg/kg of P. crinita extract displayed a substantial decrease in the MDA levels (P < 0.00, 26.9%, and 51.68% decrease, respectively), indicating potent antioxidant effect. Additionally, the pretreated groups with PCSeNPs significantly suppressed the MDA levels (P < 0.00, 54.77%, and 65.08% decreases, respectively). The results of immune-histochemical staining revealed moderate COX-2 and Il-1β expressions with scores 2 and 1 in rats pre-treated with 25 and 50 mg/kg of free extract, respectively. Additionally, the rats pre-treated with different doses of PCSeNPs demonstrated weak COX-2 and Il-1β expressions with score 1 (25 mg/kg) and negative expression with score 0 (50 mg/kg). Both antioxidant and anti-inflammatory effects were dose-dependent.

CONCLUSIONS

These distinguishing features imply that this unique alga is a promising anti-inflammatory agent. Further studies are required to investigate its main active ingredients and possible side effects.

Antimicrobial and anti-biofilm activity of silver nanoparticles biosynthesized with Cystoseira algae extracts

Antimicrobial resistance is an ever-growing global concern to public health with no clear or immediate solution. Silver nanoparticles (AgNPs) have long been proposed as efficient agents to fight the growing number of antibiotic-resistant strains. However, the synthesis of these particles is often linked to high costs and the use of toxic, hazardous chemicals, with environmental and health impact. In this study, we successfully produced AgNPs by green synthesis with the aid of the extract of two brown algae-Cystoseira baccata (CB) and Cystoseira tamariscifolia (CT)-and characterized their physico-chemical properties. The NPs produced in both cases (Ag@CB and Ag@CT) present similar sizes, with mean diameters of around 22 nm. The antioxidant activity of the extracts and the NPs was evaluated, with the extracts showing important antioxidant activity. The bacteriostatic and bactericidal properties of both Ag@CB and Ag@CT were tested and compared with gold NPs produced in the same algae extracts as previously reported. AgNPs demonstrated the strongest bacteriostatic and bactericidal properties, at concentrations as low as 2.16 µg/mL against Pseudomonas aeruginosa and Escherichia coli. Finally, the capacity of these samples to prevent the formation of biofilms characteristic of infections with a poorer outcome was assessed, obtaining similar results. This work points towards an alternative for the treatment of bacterial infections, even biofilm-inducing, with the possibility of minimizing the risk of drug resistance, albeit the necessary caution implied using metallic NPs.

Terminalia chebula-Assisted Silver Nanoparticles: Biological Potential, Synthesis, Characterization, and Ecotoxicity

In the current research, an aqueous extract of Terminalia chebula fruit was used to produce silver nanoparticles (Ag NPs) in a sustainable manner. UV-visible spectrophotometry, transmission electron microscopy (TEM), and scanning electron microscopy (SEM) were used to characterize the synthesized nanoparticles. Synthesized Ag NPs were detected since their greatest absorption peak was seen at 460 nm. The synthesized Ag NPs were spherical and had an average size of about 50 nm, with agglomerated structures, as shown via SEM and TEM analyses. The biological activities of the synthesized Ag NPs were evaluated in terms of their antibacterial and antioxidant properties, as well as protein leakage and time-kill kinetics assays. The results suggest that the green synthesized Ag NPs possess significant antibacterial and antioxidant activities, making them a promising candidate for therapeutic applications. Furthermore, the study also evaluated the potential toxicological effects of the Ag NPs using zebrafish embryos as a model organism. The findings indicate that the synthesized Ag NPs did not induce any significant toxic effects on zebrafish embryos, further supporting their potential as therapeutic agents. In conclusion, the environmentally friendly production of Ag NPs using the extract from T. chebula is a promising strategy for discovering novel therapeutic agents with prospective uses in biomedicine.

Nanoparticle delivery through the BBB in central nervous system tuberculosis

Recent advances in Nanotechnology have revolutionized the production of materials for biomedical applications. Nowadays, there is a plethora of nanomaterials with potential for use towards improvement of human health. On the other hand, very little is known about how these materials interact with biological systems, especially at the nanoscale level, mainly because of the lack of specific methods to probe these interactions. In this review, we will analytically describe the journey of nanoparticles (NPs) through the brain, starting from the very first moment upon injection. We will preliminarily provide a brief overlook of the physicochemical properties of NPs. Then, we will discuss how these NPs interact with the body compartments and biological barriers, before reaching the blood-brain barrier (BBB), the last gate guarding the brain. Particular attention will be paid to the interaction with the biomolecular, the bio-mesoscopic, the (blood) cellular, and the tissue barriers, with a focus on the BBB. This will be framed in the context of brain infections, especially considering central nervous system tuberculosis (CNS-TB), which is one of the most devastating forms of human mycobacterial infections. The final aim of this review is not a collection, nor a list, of current literature data, as it provides the readers with the analytical tools and guidelines for the design of effective and rational NPs for delivery in the infected brain.

Protection against Paraquat-Induced Oxidative Stress by Curcuma longa Extract-Loaded Polymeric Nanoparticles in Zebrafish Embryos

The link between oxidative stress and environmental factors plays an important role in chronic degenerative diseases; therefore, exogenous antioxidants could be an effective alternative to combat disease progression and/or most significant symptoms. Curcuma longa L. (CL), commonly known as turmeric, is mostly composed of curcumin, a multivalent molecule described as having antioxidant, anti-inflammatory and neuroprotective properties. Poor chemical stability and low oral bioavailability and, consequently, poor absorption, rapid metabolism, and limited tissue distribution are major restrictions to its applicability. The advent of nanotechnology, by combining nanosacale with multi-functionality and bioavailability improvement, offers an opportunity to overcome these limitations. Therefore, in this work, poly-Ɛ-caprolactone (PCL) nanoparticles were developed to incorporate the methanolic extract of CL, and their bioactivity was assessed in comparison to free or encapsulated curcumin. Their toxicity was evaluated using zebrafish embryos by applying the Fish Embryo Acute Toxicity test, following recommended OECD guidelines. The protective effect against paraquat-induced oxidative damage of CL extract, free or encapsulated in PCL nanoparticles, was evaluated. This herbicide is known to cause oxidative damage and greatly affect neuromotor functions. The overall results indicate that CL-loaded PCL nanoparticles have an interesting protective capacity against paraquat-induced damage, particularly in neuromuscular development that goes well beyond that of CL extract itself and other known antioxidants.

Evaluation of Metal‐Organic Framework MIL-89 nanoparticles toxicity on embryonic zebrafish development

Metal-Organic Framework MIL-89 nanoparticles garnered remarkable attention for their widespread use in technological applications. However, the impact of these nanomaterials on human and environmental health is still limited, and concerns regarding the potential risk of exposure during manipulation is constantly rising. Therefore, the extensive use of nanomaterials in the medical field necessitates a comprehensive assessment of their safety and interaction with different tissues of the body system. In this study, we evaluated the systemic toxicity of nanoMIL-89 using Zebrafish embryos as a model system to determine the acute developmental effect. Zebrafish embryos were exposed to a range of nanoMIL-89 concentrations (1 – 300 µM) at 4 h post-fertilization (hpf) for up to 120 hpf. The viability and hatching rate were evaluated at 24–72 hpf, whereas the cardiac function was assessed at 72 and 96 hpf, and the neurodevelopment and hepatic steatosis at 120 hpf. Our study shows that nanoMIL-89 exerted no developmental toxicity on zebrafish embryos at low concentrations (1–10 µM). However, the hatching time and heart development were affected at high concentrations of nanoMIL-89 (> 30 µM). Our findings add novel information into the available data about the in vivo toxicity of nanoMIL-89 and demonstrate its innocuity and safe use in biological, environmental, and medical applications.

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NanoMIL-89 is not lethal for zebrafish embryos.

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High concentrations of nanoMIL-89 alter the heart development and delay the hatching time in zebrafish embryos.

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Low concentrations of nanoMIL-89 showed no significant organ specific toxicity effects on zebrafish embryos.