Sodium alginate and gum acacia hydrogels of zinc oxide nanoparticles reduce hemolytic and oxidative stress inflicted by zinc oxide nanoparticles on mammalian cells

The effect of deoxycholic acid-based hydrogels on hepatic, muscle and pancreatic beta cells

Aim: The aim of this study is to test the biocompatibility of hydrogels with polysaccharides and bile acids on three murine cell lines. Materials & methods: Novel hydrogels containing poloxamer 407, polysaccharides (starch, pectin, acacia, carboxymethyl and methyl 2-hydroxyethyl cellulose) and deoxycholic acid were prepared using cold method, sterilized and used in biological assays to determine effects on hepatic, muscle, and pancreatic beta cells. Results and conclusion: Hydrogels with deoxycholic acid had tissue-depending effects on cellular survival and bioenergetics, resulting in the best cellular viability and bioenergetics within pancreatic beta cells. Further research is needed as proposed hydrogels may be beneficial for cell delivery systems of pancreatic beta cells.

Synergistic Effect of Zinc-Chitosan Nanoparticles and Hydroxychloroquine to Inhibit Buffalo Coronavirus

Zinc ions can hinder the synthesis of proteins required for accomplishing several stages of the viral life cycle. The intracellular zinc concentration can be increased by using zinc ionophores which transport zinc ions into the cells and hinder viral replication. (Hydroxy)chloroquine is an example of a zinc ionophore, but both zinc and (hydroxy)chloroquine can be toxic to the host organism. The nanocarriers may serve as camouflage to evade the adverse effects of drugs, chemicals, and nanoparticles on the host. We formulated ZnO nanoparticles with flower-like morphology (ZnONFs). It was further decorated with chitosan along with hydroxychloroquine (as a zinc ionophore) (CHCZnO NPs). We have chosen the cationic polymer chitosan since it is biocompatible, biodegradable and binds easily with the cells, and enhances the transport of drugs across cell membranes. The formulation was investigated for size, shape, surface charge, and interaction of chemicals used. We evaluated the formulations for cytotoxicity, and biocompatibility in embryonated chicks and their efficacy against bovine coronavirus (BCoV) isolated from a buffalo calf, and pneumo-enteric coronaviruses isolated from a buffalo calf with promising results in comparison to ZnONFs/hydroxychloroquine alone. Furthermore, we elucidate the mechanism underlying the lysosomotropic effect of various formulations on Vero cells infected with the buffalo coronavirus.

Chloroquine chaos and COVID-19: Smart delivery perspectives through pH sensitive polymers/micelles and ZnO nanoparticles

The global pandemic of COVID-19 had a consequential impact on our lives. (Hydroxy)chloroquine, a well-known drug for treatment or prevention against malaria and chronic inflammatory conditions, was also used for COVID patients with reported potential efficacy. Although it was well tolerated, however in some cases, it produced severe side effects, including grave cardiac issues. The variable reports on the administration of (hydroxy)chloroquine in COVID19 patients led to chaos. This drug is a well-known zinc ionophore, besides possessing antiviral effects. Zinc ionophores augment the intracellular Zn²⁺ concentration by facilitating the zinc ions into the cells and subsequently impair virus replication. Zinc oxide nanoparticles (ZnO NPs) have been reported to possess antiviral activity. However, the adverse effects of both components are also reported. We discussed in depth their possible mechanism as antiviral and smart delivery perspectives through pH-sensitive polymers/ micelles and ZnO NPs.

Metal/metal oxide nanoparticles: Toxicity concerns associated with their physical state and remediation for biomedical applications

Metal/metal oxide nanoparticles show promise for various applications, including diagnosis, treatment, theranostics, sensors, cosmetics, etc. Their altered chemical, optical, magnetic, and structural properties have differential toxicity profiles. Depending upon their physical state, these NPs can also change their properties due to alteration in pH, interaction with proteins, lipids, blood cells, and genetic material. Metallic nanomaterials (comprised of a single metal element) tend to be relatively stable and do not readily undergo dissolution. Contrarily, metal oxide and metal alloy-based nanomaterials tend to exhibit a lower degree of stability and are more susceptible to dissolution and ion release when introduced to a biological milieu, leading to reactive oxygen species production and oxidative stress to cells. Since NPs have considerable mobility in various biological tissues, the investigation related to their adverse effects is a critical issue and required to be appropriately addressed before their biomedical applications. Short and long-term toxicity assessment of metal/metal oxide nanoparticles or their nano-formulations is of paramount importance to ensure the global biome's safety; otherwise, to face a fiasco. This article provides a comprehensive introspection regarding the effects of metal/metal oxides' physical state, their surface properties, the possible mechanism of actions along with the potential future strategy for remediation of their toxic effects.

Benefits of Polyamide Nanofibrous Materials: Antibacterial Activity and Retention Ability for Staphylococcus Aureus

Although nanomaterials are used in many fields, little is known about the fundamental interactions between nanomaterials and microorganisms. To test antimicrobial properties and retention ability, 13 electrospun polyamide (PA) nanomaterials with different morphology and functionalization with various concentrations of AgNO₃ and chlorhexidine (CHX) were analyzed. Staphylococcus aureus CCM 4516 was used to verify the designed nanomaterials’ inhibition and permeability assays. All functionalized PAs suppressed bacterial growth, and the most effective antimicrobial nanomaterial was evaluated to be PA 12% with 4.0 wt% CHX (inhibition zones: 2.9 ± 0.2 mm; log₁₀ suppression: 8.9 ± 0.0; inhibitory rate: 100.0%). Furthermore, the long-term stability of all functionalized PAs was tested. These nanomaterials can be stored at least nine months after their preparation without losing their antibacterial effect. A filtration apparatus was constructed for testing the retention of PAs. All of the PAs effectively retained the filtered bacteria with log₁₀ removal of 3.3–6.8 and a retention rate of 96.7–100.0%. Surface density significantly influenced the retention efficiency of PAs (p ≤ 0.01), while the effect of fiber diameter was not confirmed (p ≥ 0.05). Due to their stability, retention, and antimicrobial properties, they can serve as a model for medical or filtration applications.

Effects of ZnO nanoparticles on flocculation and sedimentation of activated sludge in wastewater treatment process

Despite the behaviors of ZnO nanoparticles (ZnO NPs) in wastewater treatment processes have been widely explored, the impacts of ZnO NPs on the activated sludge's flocculation and sedimentation performances for solid-liquid separation have rarely been involved yet. In this study, ZnO NPs were observed to exert a dose-dependent negative effect on the sludge's flocculation performance but did not significantly impact the sludge' sedimentation behaviors. Furthermore, it was NPs themselves rather than the dissolved Zn²⁺ who impaired on the sludge flocculation performance because the Zn²⁺ alone would not compromise the sludge's flocculation efficiency. In addition, the sludge flocculation performance was revealed to be inversely related to the extracellular polymeric substances (EPS) content in the sludge and the direct contacts between ZnO NPs and the cells in the sludge should be the prerequisite to stimulate the secretion of the sludge EPS. The poor sludge flocculation performance could also be caused by the reduced protein/polysaccharide (PN/PS) ratio and the zeta (ζ) potential in the loosely bound (LB-EPS) after the sludge exposure to ZnO NPs. Fourier transform-infrared spectra (FT-IR) and three dimensional - excitation emission fluorescence spectra (3D-EEM) analysis further revealed that the decrease of the tyrosine PN-like substance level in the LB-EPS was probably the key reason for the decreased PN/PS ratio and ζ potential in the LB-EPS, which eventually induced the decline of the sludge flocculation performance under the ZnO NP stress. These results could potentially expand the knowledge on sludge flocculation and sedimentation in the presence of ZnO NPs.

Aggregation behavior of zinc oxide nanoparticles and their biotoxicity to Daphnia magna: Influence of humic acid and sodium alginate

The widespread applications of zinc oxide nanoparticles (ZnO NPs) have raised increasing concerns due to their adverse environmental effects. The ubiquitous natural organic matter in natural aqueous environments can interact with ZnO NPs, thereby affecting their aggregation, sedimentation and biotoxicity. Here, we systematically investigated the effects of humic acid (HA) and sodium alginate (SA) on the aggregation behavior of ZnO NPs and their biotoxicity to Daphnia magna. High concentrations (9.0 mg/L) of HA and SA accelerated the aggregation of ZnO NPs with maximum aggregation rates (ΔD/Δt) of 22.1 and 19.2 nm/min, respectively. Both HA and SA led to 31.2% and 30.1% decrease of ZnO NPs concentration compared with the control experiment. The results calculated by Derjaguin-Landau-Verwey-Overbeek theoretical formula were consistent with these of aggregation and sedimentation of ZnO NPs. Furthermore, excitation-emission-matrix fluorescence spectroscopy verified that the carboxylic groups of HA and SA have high complexation capacity with ZnO NPs. Daphnia magna was used to evaluate the biotoxicity of ZnO NPs, and the toxicity of ZnO NPs to Daphnia magna was alleviated as the HA concentration increased from 0 to 1.2 mg/L. Toxicity mitigation experiments confirmed that photocatalytic generation of reactive oxygen species was more toxic to Daphnia magna than dissolved Zn²⁺ in acute and chronic toxicity tests. Moreover, the attacks of active oxygen free radical damaged the antioxidant system of Daphnia magna. The information obtained will help us to improve the understanding of the impacts of ZnO NPs on freshwater ecosystems.

Microwave assisted fast fabrication of zinc/iron oxides based polymeric nanocomposites and evaluation on equine fibroblasts

We aimed to provide a tissue repair material, which can be synthesized rapidly, using polymers mimicking the natural environment in the extra-cellular matrix and metals/minerals. The components should have the potential to be used in tissue repair and simultaneously, reducing the side-effects of the incorporated molecules. It is challenging to manage the dispersibility of ZnO NPs in common solutions like water. Here, we report a novel method for preparing highly dispersible suspensions of ZnO NPs. In contrast to those synthesized by conventional methods, microwave assisted method allowed synthesis of dispersible ZnO NPs and the incorporation of zinc/Iron oxides NPs within alginate and gum matrix (AG) in a short span of time providing high yield of the product. The nanoformulations were characterized for size, morphology, interaction of various chemicals used during their synthesis by transmissible electron microscopy, X-ray diffraction, Fourier transform infrared spectroscopy and energy dispersive X ray Spectrum. It was also evaluated for cytotoxicity and their effect on equine fibroblast cells. Microwave-assisted fabrication of zinc/iron oxides nanoparticles provided flowerlike morphology with good dispersibility and high yield in a short span of time. Our results revealed that ZnO NPs were more cytotoxic than AG ZnO NPs and doped AG Fe₃O₄ doped ZnO NPs at higher concentrations. Further metal nanoparticles capped with alginate/acacia with size range less than 100 nm demonstrated high stability, good biocompatibility, re-epithelization and enhanced mineralization in horse fibroblast cells.

Accelerated healing of full thickness excised skin wound in rabbits using single application of alginate/acacia based nanocomposites of ZnO nanoparticles

A perfect wound covering should prevent dryness of the wound and provide a favourable moist milieu at the wound interface allowing gas access but act as a barrier to the dirt and microorganisms. It is imperative to ensure early restoration of wound without scar formation at the site. Topical application of antiseptic preparation is the best for wound treatment because of its direct action. Zinc oxide nanoparticles (ZnO NPs) possess antimicrobial activity and enhance wound healing. Biocompatible polymers for inclusion of ZnO NPs can enhance the efficacy at lower doses while reducing the unwanted toxic effects. We synthesized ZnO NPs nanocomposites by impregnating the NPs in covalently attached gum acacia to the alginate exploiting the hydroxyl groups with aldehydes of glutaraldehyde, providing hydrated environment during wound application. Its topical application accelerated the full-thickness excision wound healing in rabbits. The polymers exerted synergistic effects due to their wound-healing potential. The wound-healing process was also investigated by transmission electron microscopy of regenerated tissues, collagen contents, alizared staining and histological observations to elucidate the healing mechanism compared to a commercially available ointment and negative controls. It has promising properties of biocompatibility, anti-inflammatory, cell adhesion and proliferation without any scar formation which are crucial for healing.

Green synthesis of anisotropic zinc oxide nanoparticles with antibacterial and cytofriendly properties

Zinc oxide nanoparticles (ZnONPs) exhibit abundant biomedical applications. Anisotropic ZnONPs with a defined shape and size were synthesized using Bacillus megaterium (NCIM 2326) cell free extract as a bio-reductant. The study investigated the multidimensional effect of ZnONPs on Helicobacter pylori strains and assessed its biosafety in normal human mesenchymal stem cells (hMSc). The highly stable ZnONPs were produced using B. megaterium and Zinc nitrate as a precursor. The phase of ZnONPs formation and structural characterization were performed by UV- visible (UV-Vis), Fourier transform infrared (FTIR) spectroscopy, X-ray diffraction (XRD) and Field Emission Scanning electron microscopy (FESEM) analysis. Furthermore, the ZnONPs exhibited higher biocompatibility against human mesenchymal stem cells (hMSC) and proved to be potentially safe in mammalian cells. Corroborating the current investigation, we described the anti-H. Pylori dosage of ZnONPs was safe to hMSC and could efficiently use as nano-antibiotic.