Sodium Lignosulfonate Induced Vaterite Calcium Carbonate with Multilayered Structure

Insights into the physico-chemical and biological characterization of sodium lignosulfonate - silver nanosystems designed for wound management

Chronic wounds represent one of the complications that might occur from the disruption of wound healing process. Recently, there has been a rise in interest in employing nanotechnology to develop novel strategies for accelerating wound healing. The aim of the present study was to use a green synthesis method to obtain AgNPs/NaLS systems useful for wounds management and perform an in-depth investigation of their behavior during and post-synthesis as well as of their biological properties. The colloids obtained from silver nanoparticles (AgNPs) and commercial sodium lignosulfonate (NaLS) in a single-pot aqueous procedure have been fully characterized by UV-Vis, FT-IR, DLS, TEM, XRD, and XPS to evaluate the synthesis efficiency and to provide new insights in the process of AgNPs formation and NaLS behavior in aqueous solutions. The effects of various concentrations of NaLS (0-16 mg/mL) and AgNO3 (0-20 mM) and of two different temperatures on AgNPs formation have been analyzed. Although the room temperature is feasible for AgNPs synthesis, the short mixing at 70 °C significantly increases the speed of nanoparticle formation and storage stability. In all experimental conditions AgNPs of 20-40 nm in size have been obtained. The antimicrobial activity assessed quantitatively on clinical and reference bacterial strains, both in suspension and biofilm growth state, revealed a broad antimicrobial spectrum, the most intensive inhibitory effect being noticed against Pseudomonas aeruginosa and Escherichia coli strains. The AgNP/NaLS enhanced the NO extracellular release, potentially contributing to the microbicidal and anti-adherence activity by protein oxidation. Both AgNP/NaLS and NaLS were non-hemolytic (hemolytic index<5%, 2.26 ± 0.13% hemolysis) and biocompatible (102.17 ± 3.43 % HaCaT cells viability). The presence of AgNPs increased the antioxidative activity and induced a significant cytotoxicity on non-melanoma skin cancer cells (62.86 ± 8.27% Cal-27 cells viability). Taken together, all these features suggest the multivalent potential of these colloids for the development of novel strategies for wound management, acting by preventing infection-associated complications and supporting the tissue regeneration.

Hazard Assessment of the Effects of Acute and Chronic Exposure to Permethrin, Copper Hydroxide, Acephate, and Validamycin Nanopesticides on the Physiology of Drosophila: Novel Insights into the Cellular Internalization and Biological Effects

New insights into the interactions between nanopesticides and edible plants are required in order to elucidate their impacts on human health and agriculture. Nanopesticides include formulations consisting of organic/inorganic nanoparticles. Drosophila melanogaster has become a powerful model in genetic research thanks to its genetic similarity to mammals. This project mainly aimed to generate new evidence for the toxic/genotoxic properties of different nanopesticides (a nanoemulsion (permethrin nanopesticides, 20 ± 5 nm), an inorganic nanoparticle as an active ingredient (copper(II) hydroxide [Cu(OH)₂] nanopesticides, 15 ± 6 nm), a polymer-based nanopesticide (acephate nanopesticides, 55 ± 25 nm), and an inorganic nanoparticle associated with an organic active ingredient (validamycin nanopesticides, 1177 ± 220 nm)) and their microparticulate forms (i.e., permethrin, copper(II) sulfate pentahydrate (CuSO₄·5H₂O), acephate, and validamycin) widely used against agricultural pests, while also showing the merits of using Drosophila—a non-target in vivo eukaryotic model organism—in nanogenotoxicology studies. Significant biological effects were noted at the highest doses of permethrin (0.06 and 0.1 mM), permethrin nanopesticides (1 and 2.5 mM), CuSO₄·5H₂O (1 and 5 mM), acephate and acephate nanopesticides (1 and 5 mM, respectively), and validamycin and validamycin nanopesticides (1 and 2.5 mM, respectively). The results demonstrating the toxic/genotoxic potential of these nanopesticides through their impact on cellular internalization and gene expression represent significant contributions to future nanogenotoxicology studies.

Composite Porous Liquid for Recyclable Sequestration, Storage and In Situ Catalytic Conversion of Carbon Dioxide at Room Temperature

Permanent pores combined with fluidity renders flow processability to porous liquids otherwise not seen in porous solids. Although porous liquids have been utilized for sequestration of different gases and their separation, there is still a dearth of studies for deploying in situ chemical reactions to convert adsorbed gases into utility chemicals. Here, we show the design and development of a new type of solvent-less and hybrid (meso-)porous liquid composite, which, as demonstrated for the first time, can be used for in situ carbon mineralization of adsorbed CO₂ . The recyclable porous liquid composite comprising polymer-surfactant modified hollow silica nanorods and carbonic anhydrase enzyme not only sequesters (5.5 cm³  g^-1 at 273 K and 1 atm) and stores CO₂ but is also capable of driving an in situ enzymatic reaction for hydration of CO₂ to HCO₃ ^- ion, subsequently converting it to CaCO₃ due to reaction with pre-dissolved Ca²⁺ . Light and electron microscopy combined with X-ray diffraction reveals the nucleation and growth of calcite and aragonite crystals. Moreover, the liquid-like property of the porous composite material can be harnessed by executing the same reaction via diffusion of complimentary Ca²⁺ and HCO₃ ^- ions through different compartments separated by an interfacial channel. These studies provide a proof of concept of deploying chemical reactions within porous liquids for developing utility chemical from adsorbed molecules.

A study of the effects of NH4+ on the fast precipitation of vaterite CaCO3 formed from steamed ammonia liquid waste and K2CO3/Na2CO3

The results indicated that the CaCO₃ morphology, particle size, and crystal phase were significantly influenced by the NH₄⁺ concentration were investigated upon the use of steamed ammonia liquid waste (CaCl₂) in a rapid fabrication technique.

Preparation of vaterite calcium carbonate granules from discarded oyster shells as an adsorbent for heavy metal ions removal

We used discarded oyster shells to prepare vaterite calcium carbonate microparticles and explored the removal effects and the underlying mechanism toward several heavy metal ions. The removal efficiency for each ion type was: Pb²⁺ (99.9%), Cr³⁺ (99.5%), Fe³⁺ (99.3%), and Cu²⁺ (57.1%). With the exception of Cu²⁺, vaterite calcium carbonate particles exhibited excellent removal performance on all tested heavy metal ions, with exceptional results for Pb²⁺. The factor affecting the removal efficiency of heavy metal ions is shown to involve an ion exchange reaction between calcium and the heavy metal ions resulting in recrystallization. Vaterite calcium carbonate particles prepared by this method have the advantage of low price, easy synthesis, and reduction of environmental waste. Thus, this procedure for synthesizing vaterite CaCO₃ provides an environmentally responsible method for preparing materials that can be economically incorporated into common consumer products such as household drinking water filtration systems.

Phase selection of calcium carbonate crystals under the induction of lignin monomer model compounds

The formation and application of ‘cinnamic acid & CaCO₃ crystals’ (CACs) induced by a lignin monomer compound.

Investigation of calcium carbonate synthesized by steamed ammonia liquid waste without use of additives

The aim of this work is to study the effect of reaction conditions using steamed ammonia liquid waste without the use of additives on the crystallization of calcium carbonate. CaCO₃ was prepared by steamed ammonia liquid waste (CaCl₂) and (NH₄)₂CO₃ solution. The produced crystals were characterized by scanning electron microscopy (SEM), Fourier transform infrared spectrometry (FTIR) and X-ray diffraction (XRD). We have investigated the effect of the concentration of reactants, stirring speed, Ca²⁺ : CO₃²⁻ ratio, aging time and adding mode on the particle size and size distribution, final morphology and polymorph of calcium carbonate crystals during precipitation. The influence of concentration of reactants, stirring speed, Ca²⁺ : CO₃²⁻ ratio, aging time and adding mode on the morphology, size and polymorph of CaCO₃ particles and possible formation mechanism were discussed. The exploration provides the possibility for large-scale synthesis of CaCO₃ materials with controllable morphology and crystallographic structure by steamed ammonia liquid waste without use of additives at room temperature.

The aim of this work is to study the effect of reaction conditions using steamed ammonia liquid waste without the use of additives on the crystallization of calcium carbonate.

Cellulose/vaterite nanocomposites: Sonochemical synthesis, characterization, and their application in protein adsorption

Vaterite is recognized as an important biomedical material owing to its features such as high specific surface area, high solubility, high dispersion, and small specific gravity. Herein, we report a facile and green sonochemical route to prepare vaterite nanospheres (assembled from rice-shaped nanoparticles) with average diameter of 206-246 nm by using cellulose as substrate. The important role of cellulose concentration on the phase of the products was systematically investigated, and the formation mechanism of vaterite was proposed. Moreover, the as-prepared cellulose/vaterite nanocomposites have a good cytocompatibility and a relatively high protein adsorption ability using hemoglobin as a model protein. These results indicate that the as-prepared cellulose/vaterite nanocomposites are promising for applications in biomedical fields, such as protein adsorption.

Intracellular carbonic anhydrase from Citrobacter freundii and its role in bio-sequestration

The aim of this work was to study the CO₂ bio-sequestration application of indigenous Citrobacter species and its carbonic anhydrase (CA). Intracellular CA was purified from Citrobacter freundii (CF; accession no: MH283871) isolated from limestone rock site in Kumaun region of Indian Himalaya studied for the sequestration of carbon dioxide and the formation of calcite. CF showed maximum CA enzyme activity at 11.3 EU/ml at pH 7.0 and 37 °C. Hydration of CO₂ into carbonate was characterized by calcite phase of calcium carbonate using absorption spectroscopy and imaging technique. Purified CA showed a significantly high CO₂ sequestration capacity of 230 mg CaCO₃/mg of purified as compared to crude enzyme (50 mg CaCO₃/ml of enzyme).

Preparation and characterization of antibacterial paper coated with sodium lignosulfonate stabilized ZnO nanoparticles

The ZnO nanoparticles were synthesized using sodium lignosulfonate as a stabilizing agent and sodium hydroxide as a precipitation agent. The negatively charged ZnO nanoparticles were deposited onto cellulose paper through a layer-by-layer approach.

Biomineralization of stable and monodisperse vaterite microspheres using silk nanoparticles

The influence of silk fibroin (SF) on calcium carbonate (CaCO3) biomineralization has been investigated; however, the formation of small, uniform SF-regulated vaterite microspheres has not been reported. In this work, spherical CaCO3 was synthesized via coprecipitation in the presence of SF. SF nanostructures were first tuned by self-assembly at 60 °C to provide better control of the nucleation of CaCO3. Subsequently, monodisperse vaterite microspheres about 1.1 μm were generated by controlling aggregation and growth of CaCO3 under appropriate concentrations of SF and Ca ions. In contrast to unstable vaterite, the microspheres generated in the present study have sufficient stability in aqueous solution for at least 8 days without transformation into calcite, due to the electrostatic interactions between the Ca ions and the preassembled SF nanostructures. The microspheres as drug carriers of doxorubicin (DOX) were assessed and found to have good encapsulation efficiency, sustained drug release without burst release, and pH sensitivity. These new SF/CaCO3 hybrids may provide new options for various biomedical applications.