“Safe” Chitosan/Zinc Oxide Nanocomposite Has Minimal Organ-Specific Toxicity in Early Stages of Zebrafish Development

Ecotoxicity and environmental safety assessment of two-dimensional niobium carbides (MXenes)

Two-dimensional (2D) MXenes have gained great interest in water treatment, biomedical, and environmental applications. The antimicrobial activity and cell toxicity of several MXenes including Nb4C3Tx and Nb2CTx have already been explored. However, potential side effects related to Nb-MXene toxicity, especially on aquatic pneuma, have rarely been studied. Using zebrafish embryos, we investigated and compared the potential acute toxicity between two forms of Nb-MXene: the multilayer (ML-Nb4C3Tx, ML-Nb2CTx) and the delaminated (DL-Nb2CTx, and DL-Nb4C3Tx) Nb-MXene. The LC50 of ML-Nb4C3Tx, ML-Nb2CTx, DL-Nb2CTx, and DL-Nb4C3Tx were estimated to be 220, 215, 225, and 128 mg/L, respectively. Although DL-Nb2CTx, and DL-Nb4C3Tx derivatives have similar sizes, DL-Nb4C3Tx not only shows the higher mortality (LC50 = 128 mg/L Vs 225 mg/L), but also the highest teratogenic effect (NOEC = 100 mg/L Vs 200 mg/L). LDH release assay suggested more cell membrane damage and a higher superoxide anion production in DL-Nb4C3Tx than DL-Nb2CTx,. Interestingly, both DL-Nb-MXene nanosheets showed insignificant cardiac, hepatic, or behavioral toxic effects compared to the negative control. Embryos treated with the NOEC of DL-Nb2CTx presented hyperlocomotion, while embryos treated with the NOEC of DL-Nb4C3Tx presented hyperlocomotion, suggesting developmental neurotoxic effect and muscle impairment induced by both DL-Nb-MXene. According to the Fish and Wildlife Service (FSW) Acute Toxicity Rating Scale, all tested Nb-MXene nanosheets were classified as "Practically not toxic". However, DL-Nb4C3Tx should be treated with caution as it might cause a neurotoxic effect on fauna when it ends up in wastewater in high concentrations.

Recent development of carrier materials in anthocyanins encapsulation applications: A comprehensive literature review

Anthocyanins are natural polyphenols belonging to the flavonoid family that possess a variety of putative health benefits when consumed in a balanced diet. However, applications of anthocyanins in, for example, functional foods are limited due to poor stability, degradation, and low transmembrane efficiency. To maintain bioactivities of anthocyanins and optimize their use, various carrier materials have been developed. Here, we reviewed the uses of the different carrier materials (organic/inorganic, micro/nano) for anthocyanin encapsulation and delivery over the past five years. The performance of different materials and interactions between anthocyanins and these materials are described. Lastly, we give our perspective on the future development trend of anthocyanin encapsulation strategies.

Exploring the current landscape of chitosan-based hybrid nanoplatforms as cancer theragnostic

In the last decade, investigators have put significant efforts to develop several diagnostic and therapeutic strategies against cancer. Many novel nanoplatforms, including lipidic, metallic, and inorganic nanocarriers, have shown massive potential at preclinical and clinical stages for cancer diagnosis and treatment. Each of these nano-systems is distinct with its own benefits and limitations. The need to overcome the limitations of single-component nano-systems, improve their morphological and biological features, and achieve multiple functionalities has resulted in the emergence of hybrid nanoparticles (HNPs). These HNPs integrate multicomponent nano-systems with diagnostic and therapeutic functions into a single nano-system serving as promising nanotools for cancer theragnostic applications. Chitosan (CS) being a mucoadhesive, biodegradable, and biocompatible biopolymer, has emerged as an essential element for the development of HNPs offering several advantages over conventional nanoparticles including pH-dependent drug delivery, sustained drug release, and enhanced nanoparticle stability. In addition, the free protonable amino groups in the CS backbone offer flexibility to its structure, making it easy for the modification and functionalization of CS, resulting in better drug targetability and cell uptake. This review discusses in detail the existing different oncology-directed CS-based HNPs including their morphological characteristics, in-vitro/in-vivo outcomes, toxicity concerns, hurdles in clinical translation, and future prospects.

Chitosan nanocomposite for tissue engineering and regenerative medicine: A review

Regenerative medicine and tissue engineering have emerged as a multidisciplinary promising field in the quest to address the limitations of traditional medical approaches. One of the key aspects of these fields is the development of such types of biomaterials that can mimic the extracellular matrix and provide a conducive environment for tissue regeneration. In this regard, chitosan has played a vital role which is a naturally derived linear bi-poly-aminosaccharide, and has gained significant attention due to its biocompatibility and unique properties. Chitosan possesses many unique physicochemical properties, making it a significant polysaccharide for different applications such as agriculture, nutraceutical, biomedical, food, nutraceutical, packaging, etc. as well as significant material for developing next-generation hydrogel and bio-scaffolds for regenerative medicinal applications. Moreover, chitosan can be easily modified to incorporate desirable properties, such as improved mechanical strength, enhanced biodegradability, and controlled release of bioactive molecules. Blending chitosan with other polymers or incorporating nanoparticles into its matrix further expands its potential in tissue engineering applications. This review summarizes the most recent studies of the last 10 years based on chitosan, blends, and nanocomposites and their application in bone tissue engineering, hard tissue engineering, dental implants, dental tissue engineering, dental fillers, and cartilage tissue engineering.

Nanobiotechnology-based strategies in alleviation of chemotherapy-mediated cardiotoxicity

The cardiovascular diseases have been among the most common malignancies and the first leading cause of death, even higher than cancer. The cardiovascular diseases can be developed as a result of cardiac dysfunction and damages to heart tissue. Exposure to toxic agents and chemicals that induce cardiac dysfunction has been of interest in recent years. The chemotherapy drugs are commonly used for cancer therapy and in these patients, cardiovascular diseases have been widely observed that is due to negative impact of chemotherapy drugs on the heart. These drugs increase oxidative damage and inflammation, and mediate apoptosis and cardiac dysfunction. Hence, nanotechnological approaches have been emerged as new strategies in attenuation of chemotherapy-mediated cardiotoxicity. The first advantage of nanoparticles can be explored in targeted and selective delivery of drugs to reduce their accumulation in heart tissue. Nanostructures can deliver bioactive and therapeutic compounds in reducing cardiotoxicity and alleviation toxic impacts of chemotherapy drugs. The functionalization of nanostructures increases their selectivity against tumor cells and reduces accumulation of drugs in heart tissue. The bioplatforms such as chitosan and alginate nanostructures can also deliver chemotherapy drugs and reduce their cardiotoxicity. The function of nanostructures is versatile in reduction of cardiotoxicity by chemotherapy drugs and new kind of platforms is hydrogels that can mediate sustained release of drug to reduce its toxic impacts on heart tissue. The various kinds of nanoplatforms have been developed for alleviation of cardiotoxicity and their future clinical application depends on their biocompatibility. High concentration level of chitosan nanoparticles can stimulate cardiotoxicity. Therefore, if nanotechnology is going to be deployed for drug delivery and reducing cardiotoxicity, the first pre-requirement is to lack toxicity on normal cells and have high biocompatibility.

Fabrication of chitosan and Trianthema portulacastrum mediated copper oxide nanoparticles: Antimicrobial potential against MDR bacteria and biological efficacy for antioxidant, antidiabetic and photocatalytic activities

Biopolymer based metal oxide nanoparticles, prepared by eco-friendly approach, are gaining interest owing to their wide range of applications. In this study, aqueous extract of Trianthema portulacastrum was used for the green synthesis of chitosan base copper oxide (CH-CuO) nanoparticles. The nanoparticles were characterized through UV-Vis Spectrophotometry, SEM, TEM, FTIR and XRD analysis. These techniques provided evidence for the successful synthesis of the nanoparticles, having poly-dispersed spherical shaped morphology with average crystallite size of 17.37 nm. The antibacterial activity for the CH-CuO nanoparticles was determined against multi-drug resistant (MDR), Escherichia coli, Pseudomonas aeruginosa (gram-negative), Enterococcus faecium and Staphylococcus aureus (gram-positive). Maximum activity was obtained against Escherichia coli (24 ± 1.99 mm) while least activity was observed against Staphylococcus aureus (17 ± 1.54 mm). In-vitro analysis for biofilm inhibition, EPS and cell surface hydrophobicity showed >60 % inhibitions for all the bacterial isolates. Antioxidant and photocatalytic assays for the nanoparticles showed significant activities of radical scavenging (81 ± 4.32 %) and dye degradation (88 %), respectively. Antidiabetic activity for the nanoparticles, determined by in-vitro analysis of alpha amylase inhibition, showed enzyme inhibition of 47 ± 3.29 %. The study signifies the potential of CH-CuO nanoparticle as an effective antimicrobial agent against MDR bacteria along with the antidiabetic and photocatalytic activities.

Nanotechnology: the Alternative and Efficient Solution to Biofouling in the Aquaculture Industry

Biofouling is a global issue in aquaculture industries. It adversely affects marine infrastructure (ship's hulls, mariculture cages and nets, underwater pipes and filters, building materials, probes, and sensor devices). The estimated cost of managing marine biofouling accounts for 5-10% of production cost. Non-toxic foul-release coating and biocide-based coating are the two current approaches. Recent innovation and development of a surface coating with nanoparticles such as photocatalytic zinc oxide nanocoating on fishing nets, copper oxide nanocoating on the water-cooling system, and silver nanoparticle coating to inhibit microalgal adhesion on submerged surfaces under natural light (photoperiod) could present meaningful anti-biofouling application. Nanocoating of zinc, copper, and silver oxide is an environmentally friendly surface coating strategy that avoid surface adhesion of bacteria, diatoms, algal, protozoans, and fungal species. Such nanocoating could also provide a solution to strains tolerant to Cu, Zn, and Ag. This draft of the special issue demonstrates the anti-biofouling potential of various metal and metal oxide nanoparticle coating to combat aquaculture industry biofouling problems.

Pectin functionalized metal-organic frameworks as dual-stimuli-responsive carriers to improve the pesticide targeting and reduce environmental risks

Encapsulation of active ingredients into intelligent response controlled release carriers has been recognized as a promising approach to enhance the utilization efficiency and reduce the environmental risks of pesticides. In this work, an intelligent redox and pectinase dual stimuli-responsive pesticide delivery system was constructed by bonding pectin with metal-organic frameworks (FeMOF nanoparticles) which were loaded with pyraclostrobin (PYR@FeMOF-pectin nanoparticles). The successful fabrication of PYR@FeMOF-pectin nanoparticles was proved by a series of physicochemical characterizations. The results indicated that the loading capacity of PYR@FeMOF-pectin nanoparticles for pyraclostrobin was approximately 20.6%. The pectin covered on the surface of PYR@FeMOF nanoparticles could protect pyraclostrobin from photolysis and improve their spreadability on rice blades effectively. Different biological stimuli associated with Magnaporthe oryzae could trigger the release of pyraclostrobin from the pesticide-loaded core-shell nanoparticles, resulting in the death of pathogens. The bioactivity survey determined that PYR@FeMOF-pectin nanoparticles had a superior fungicidal activity and a longer duration against Magnaporthe oryzae than pyraclostrobin suspension concentrate. In addition, the FeMOF-pectin nanocarriers showed no obvious phytotoxicity and could enhance the shoot length and root length of rice plants. More importantly, PYR@FeMOF-pectin nanoparticles had an 8-fold reduction in acute toxicity to zebrafish than that of pyraclostrobin suspension concentrate. Therefore, the dual-responsive FeMOF-pectin nanocarriers have great potential for realizing site-specific pesticide delivery and promoting plant growth.

Dissolution and Biological Assessment of Cancer-Targeting Nano-ZIF-8 in Zebrafish Embryos

Cancer-targeting nanotherapeutics offer promising opportunities for selective delivery of cytotoxic chemotherapeutics to cancer cells. However, the understanding of dissolution behavior and safety profiles of such nanotherapeutics is scarce. In this study, we report the dissolution profile of a cancer-targeting nanotherapeutic, gemcitabine (GEM) encapsulated within RGD-functionalized zeolitic imidazolate framework-8 (GEM⊂RGD@nZIF-8), in dissolution media having pH = 6.0 and 7.4. GEM⊂RGD@nZIF-8 was not only responsive in acidic media (pH = 6.0) but also able to sustain the dissolution rate (57.6%) after 48 h compared to non-targeting nanotherapeutic GEM⊂nZIF-8 (76%). This was reflected by the f₂ value of 36.1, which indicated a difference in the dissolution behaviors of GEM⊂RGD@nZIF-8 and GEM⊂nZIF-8 in acidic media compared to those in neutral media (pH = 7.4). A dissolution kinetic study showed that the GEM release mechanism from GEM⊂RGD@nZIF-8 followed the Higuchi model. In comparison to a non-targeting nanotherapeutic, the cancer-targeting nanotherapeutic exhibited an enhanced permeability rate in healthy zebrafish embryos but did not induce lethality to 50% of the embryos (LC₅₀ > 250 μg mL^-1) with significantly improved survivability (75%) after 96 h of incubation. Monitoring malformation showed minimal adverse effects with only 8.3% of edema at 62.5 μg mL^-1. This study indicates that cancer-targeting GEM⊂RGD@nZIF, with its pH-responsive behavior for sustaining chemotherapeutic dissolution in a physiologically relevant environment and its non-toxicity toward the healthy embryos within the tested concentrations, has considerable potential for use in cancer treatment.

Chitosan-Based Nanogels: Synthesis and Toxicity Profile for Drug Delivery to Articular Joints

One important challenge in treating avascular-degraded cartilage is the development of new drugs for both pain management and joint preservation. Considerable efforts have been invested in developing nanosystems using biomaterials, such as chitosan, a widely used natural polymer exhibiting numerous advantages, i.e., non-toxic, biocompatible and biodegradable. However, even if chitosan is generally recognized as safe, the safety and biocompatibility of such nanomaterials must be addressed because of potential for greater interactions between nanomaterials and biological systems. Here, we developed chitosan-based nanogels as drug-delivery platforms and established an initial biological risk assessment for osteocartilaginous applications. We investigated the influence of synthesis parameters on the physicochemical characteristics of the resulting nanogels and their potential impact on the biocompatibility on all types of human osteocartilaginous cells. Monodisperse nanogels were synthesized with sizes ranging from 268 to 382 nm according to the acidic solution used (i.e., either citric or acetic acid) with overall positive charge surface. Our results demonstrated that purified chitosan-based nanogels neither affected cell proliferation nor induced nitric oxide production in vitro. However, nanogels were moderately genotoxic in a dose-dependent manner but did not significantly induce acute embryotoxicity in zebrafish embryos, up to 100 µg∙mL⁻¹. These encouraging results hold great promise for the intra-articular delivery of drugs or diagnostic agents for joint pathologies.

Chitosan/benzyloxy-benzaldehyde modified ZnO nano template having optimized and distinct antiviral potency to human cytomegalovirus

Utilization of biomolecules encapsulated nano particles is currently originating ample attention to generate unconventional nanomedicines in antiviral research. Zinc oxide nanoparticle has been extensively studied for antimicrobial, antifungal and antifouling properties due to high surface to volume ratios and distinctive chemical as well as physical properties. Nevertheless, still minute information is available on their response on viruses. Here, in situ nanostructured and polysaccharide encapsulated ZnO NPs are fabricated with having antiviral potency and low cytotoxicity (%viability ~ 90%) by simply controlling the formation within interspatial 3D networks of hydrogels through perfect locking mechanism. The two composites ChH@ZnO and ChB@ZnO shows exceedingly effective antiviral activity toward Human cytomegalovirus (HCMV) having cell viability 93.6% and 92.4% up to 400 μg mL^-1 concentration. This study brings significant insights regarding the role of ZnO NPs surface coatings on their nanotoxicity and antiviral action and could potentially guide to the development of better antiviral drug.

JC-10 probe as a novel method for analyzing the mitochondrial membrane potential and cell stress in whole zebrafish embryos

BACKGROUND

A sensitive method to investigate cellular stress and cytotoxicity is based on measuring mitochondrial membrane potential. Recently, JC-10, was developed to measure mitochondrial membrane potential in vitro and used as an indicator for cytotoxicity. Yet, JC-10 has never been used in vivo (whole organism). In normal cells, JC-10 concentrates in the mitochondrial matrix, where it forms red fluorescent aggregates. However, in apoptotic/necrotic cells, JC-10 diffuses out of the mitochondria, changes to monomeric form, and stains cells in green. Here, we aimed to develop and optimize a JC-10 assay to measure cytotoxicity in zebrafish embryo. We also investigated the effectiveness of JC-10 assay by comparing it to common cytotoxicity assays.

METHODS

Zebrafish embryos were exposed to a toxic surfactant AEO-7 at no observed effect concentration (6.4 μg/L), and then cytotoxicity was measured using (i) JC-10 mitochondrial assay, (ii) acridine orange (AO), (iii) TUNEL assay, and (iv) measuring the level of Hsp70 by western blotting.

RESULTS

As compared to the negative control, embryos treated with NOEC of AEO-7 did not show significant cytotoxicity when assessed by AO, TUNEL or western blotting. However, when JC-10 was used under the same experimental conditions, a significant increase of green:red fluorescent ratio signal was detected in the AEO-7 treated embryos, indicating mitochondrial damage and cellular cytotoxicity. Noteworthy, the observed green: red ratio increase was dose dependent, suggesting specificity of the JC-10 assay.

CONCLUSION

JC-10 is a sensitive in vivo method, thus, can be used as surrogate assay to measure cytotoxicity in whole zebrafish embryos.

Eco-friendly highly efficient BN/rGO/TiO2 nanocomposite visible-light photocatalyst for phenol mineralization

Boron nitride (BN) and reduced graphene oxide (rGO) of different loadings were composited with commercial P25 TiO₂ (Ti) through the hydrothermal method. The as-prepared nanocomposites were characterized using various techniques: X-ray photoelectron spectroscopy, X-ray diffraction, thermal gravimetric analysis, Fourier transform infrared and Raman spectroscopies, and transmission and scanning electron microscopies. It was observed that 10% and 0.1% of BN and rGO, respectively, loaded on TiO₂ (10BNr0.1GOTi) resulted in the best nanocomposite in terms of phenol degradation under simulated sunlight. A 93.4% degradation of phenol was obtained within 30 min in the presence of H₂O₂. Finally, to ensure the safe use of BNrGOTi nanoparticles in the aquatic environment, acute zebrafish toxicity (acutoxicity) assays were studied. The 96-h acute toxicity assays using the zebrafish embryo model revealed that the LC₅₀ for the BNrGOTi nanoparticle was 677.8 mg L^-1 and the no observed effect concentration (NOEC) was 150 mg L^-1. Therefore, based on the LC₅₀ value and according to the Fish and Wildlife Service Acute Toxicity Rating Scale, BNrGOTi is categorized as a "practically not toxic" photocatalyst for water treatment.

A Review on Conventional and Advanced Methods for Nanotoxicology Evaluation of Engineered Nanomaterials

Nanotechnology can be defined as the field of science and technology that studies material at nanoscale (1-100 nm). These nanomaterials, especially carbon nanostructure-based composites and biopolymer-based nanocomposites, exhibit excellent chemical, physical, mechanical, electrical, and many other properties beneficial for their application in many consumer products (e.g., industrial, food, pharmaceutical, and medical). The current literature reports that the increased exposure of humans to nanomaterials could toxicologically affect their environment. Hence, this paper aims to present a review on the possible nanotoxicology assays that can be used to evaluate the toxicity of engineered nanomaterials. The different ways humans are exposed to nanomaterials are discussed, and the recent toxicity evaluation approaches of these nanomaterials are critically assessed.

Organ-specific toxicity evaluation of stearamidopropyl dimethylamine (SAPDMA) surfactant using zebrafish embryos

Surfactants are widely used in the industry of detergents, household products, and cosmetics. SAPDMA is a cationic surfactant that is used mostly in cosmetics, conditioning agents and has recently gained attention as a corrosion inhibitor in the sea pipelines industry. In this regard, literature concerning the ecotoxicological classification of SAPDMA on aquatic animals is lacking. This study aims to evaluate the potential ecotoxicity of SAPDMA using the aquatic zebrafish embryo model. The potential toxic effects of SAPDMA were assessed by different assays. This includes (i) mortality/survival assay to assess the median lethal concentration (LC₅₀); (ii) teratogenicity assay to assess the no observed effect concentration (NOEC); (iii) organ-specific toxicity assays including cardiotoxicity, neurotoxicity (using locomotion assay), hematopoietic toxicity (hemoglobin synthesis using o-dianisidine staining), hepatotoxicity (liver steatosis and yolk retention using Oil Red O (ORO) stain); (iv) cellular cytotoxicity (mitochondrial membrane potential) by measuring the accumulation of JC-1 dye into mitochondria. Exposure of embryos to SAPDMA caused mortality in a dose-dependent manner with a calculated LC₅₀ of 2.3 mg/L. Thus, based on the LC₅₀ value and according to the Fish and Wildlife Service (FWS) Acute Toxicity Rating Scale, SAPDMA is classified as "moderately toxic". The No Observed Effect Concentration (NOEC) concerning a set of parameters including scoliosis, changes in body length, yolk, and eye sizes was 0.1 mg/L. At the same NOEC concentration (0.1 mg/L), no organ-specific toxicity was detected in fish treated with SAPDMA, except hepatomegaly with no associated liver dysfunctions. However, higher SAPDMA concentrations (0.8 mg/L) have dramatic effects on zebrafish organ development (eye, heart, and liver development). Our data recommend a re-evaluation of the SAPDMA employment in the industry setting and its strictly monitoring by environmental and public health agencies.

Resveratrol Inhibits Oxidative Stress and Prevents Mitochondrial Damage Induced by Zinc Oxide Nanoparticles in Zebrafish (Danio rerio)

Despite their wide industrial use, Zinc oxide (ZnO) nanoparticles (NPs) exhibit a high toxic potential while concerns of their health-related risks are still present, urging additional in vivo clarification studies. Oxidative stress is recognized as the primary trigger of NP-associated toxicity, suggesting antioxidants as a promising counteractive approach. Here, we investigated the protective effect of the natural antioxidant resveratrol against ZnO NP-induced toxicity in vivo using the zebrafish model. Our findings demonstrate that resveratrol counteracts ZnO NP-induced zebrafish lethality preventing cardiac morphological and functional damage. NP-induced vascular structural abnormalities during embryonic fish development were significantly counteracted by resveratrol treatment. Mechanistically, we further showed that resveratrol inhibits ROS increase, prevents mitochondrial membrane potential dysfunction, and counteracts cell apoptosis/necrosis elicited by ZnO NP. Overall, our data provide further evidence demonstrating the primary role of oxidative stress in NP-induced damage, and highlight new insights concerning the protective mechanism of antioxidants against nanomaterial toxicity.

Synthesis, Bioapplications, and Toxicity Evaluation of Chitosan-Based Nanoparticles

The development of advanced nanomaterials and technologies is essential in biomedical engineering to improve the quality of life. Chitosan-based nanomaterials are on the forefront and attract wide interest due to their versatile physicochemical characteristics such as biodegradability, biocompatibility, and non-toxicity, which play a promising role in biological applications. Chitosan and its derivatives are employed in several applications including pharmaceuticals and biomedical engineering. This article presents a comprehensive overview of recent advances in chitosan derivatives and nanoparticle synthesis, as well as emerging applications in medicine, tissue engineering, drug delivery, gene therapy, and cancer therapy. In addition to the applications, we critically review the main concerns and mitigation strategies related to chitosan bactericidal properties, toxicity/safety using tissue cultures and animal models, and also their potential environmental impact. At the end of this review, we also provide some of future directions and conclusions that are important for expanding the field of biomedical applications of the chitosan nanoparticles.