CaCO3 Nanoparticles Research Articles

Redox/Near-Infrared Dual-Responsive Hollow Mesoporous Organosilica Nanoparticles for Pesticide Smart Delivery.

Extremely inefficient utilization of pesticides has prompted a study of low-cost, sustainable, and smart application systems. Herein, as a promising pesticide nanocarrier, hollow mesoporous organosilica nanoparticles (HMONs) were first synthesized by using inexpensive CaCO3 nanoparticles as the hollow templates. A redox/near-infrared light dual-triggered pesticide release system was further achieved via loading avermectin (AVM) into the HMONs and coating a layer of polydopamine (PDA). The as-prepared AVM@HMONs@PDA displays a favorable pesticide load capability (24.8 wt %), outstanding photothermal performance, and high adhesion to leaves. In addition, with glutathione (GSH), the AVM cumulative release from AVM@HMONs@PDA was 3.5 times higher than that without GSH. Under ultraviolet light irradiation, the half-life of AVM@HMONs@PDA was prolonged by 17.0-fold compared to that of the AVM technical. At day 21 after treatment in the insecticidal activity, the median lethal concentrations (LC50) values displayed that the toxicity of AVM@HMONs@PDA for Panonychus citri (McGregor) was enhanced 4.0-fold compared with the commercial emulsifiable concentrate. In the field trial, at day 28 after spraying, AVM@HMONs@PDA was significantly more control effective than AVM-EC in controlling the P. citri (McGregor), even at a 50% reduced dosage. Moreover, HMONs@PDA was safe for crops. This research presents a novel preparation approach for HMONs, and it also offers a promising nanoplatform for the precise release of pesticides.

Microfluidic Vaterite Synthesis: Approaching the Nanoscale Particles

The challenge of continuous CaCO3 particle synthesis is addressed using microfluidic technology. A custom microfluidic chip was used to synthesize CaCO3 nanoparticles in vaterite form. Our focus revolved around exploring one-phase and two-phase synthesis methods tailored for the crystallization of these nanoparticles. The combination of scanning electron microscopy, X-ray diffraction, dynamic light scattering, and small-angle scattering allowed for an evaluation of the synthesis efficiency, including the particle size distribution, morphology, and polymorph composition. The results demonstrated the superior performance of the two-phase system when precipitation occurred inside emulsion microreactors, providing improved size control compared with the one-phase approach. We also discussed insights into particle size changes during the transition from one-phase to two-phase synthesis. The ability to obtain CaCO3 nanoparticles in the desired polymorph form (∼50 nm in size, 86–99% vaterite phase) with the possibility of scaling up the synthesis will open up opportunities for various industrial applications of the developed two-phase microfluidic method.

Chemically Modified Nanoparticles for Enhanced Antioxidant and Antimicrobial Properties with Cinnamon Essential Oil.

We explored the potential of different nanoparticles (TiO2, CaCO3, and Al2O3), considering their pure form and modified with cinnamon essential oil (CEO). These materials were characterized using various techniques, including FTIR spectroscopy, XRD analysis, TGA, and SEM. The interaction between CEO and nanoparticles changed depending on the nanoparticle type. Al2O3 nanoparticles exhibited the strongest interaction with CEO, increasing their antioxidant capacity by around 40% and their transfer of antimicrobial properties, particularly against Gram-negative bacteria. In contrast, TiO2 and CaCO3 nanoparticles showed limited interaction with CEO, resulting in lower antioxidant capacity and antimicrobial activity. Incorporating pure and CEO-modified nanoparticles into polylactic acid (PLA) films improved their mechanical and thermal properties, which are suitable for applications requiring greater strength. This research highlights the potential of metal oxide nanoparticles to enhance the antimicrobial and antioxidant capabilities of polymers. In addition, incorporating cinnamon essential oil can increase the antioxidant and antimicrobial effectiveness of the metal oxide nanoparticles and improve the mechanical and thermal properties of PLA films. Thus, these PLA films exhibit favorable characteristics for active packaging applications.

Morphological Characterization of Calcium Carbonate Nanoparticles Derived from Blood Cockle Shells (Anadara granosa)

Blood cockle shells are a type of shellfish with distinctive bright red color that is commonly found in coastal areas of Asia, a rich source of protein, vitamins, and minerals, including calcium carbonate. Calcium carbonate (CaCO3) is a common mineral supplement that slowly paved its way into nano research to support bone health that also used in the treatment of bone infections due to its inherent properties; reduces inflammation, promotes bone healing, crucial role in the immune system, and slow degradability. The latest invention on CaCO3 from cockle shells, is an alternative mode of drug delivery to circumvent existing antibiotic resistance mechanisms and allow direct drug delivery to the target site, using locally sourced ingredients to reduce long-term high production costs. A top-down approach CaCO3 nanoparticles from blood cockle (Anadara granosa) shells were developed, known as calcium carbonate nanoparticles (CNPs). This research aims to characterize the morphology of CNPs from blood cockle shells via Transmission Electron Microscopy (TEM), Scanning Electron Microscopy (SEM), and Atomic Force Microscopy (AFM). A homogeneously spherical CNPs. with a mean diameter of 36.5 ± 2.3 nm was observed on TEM, so as FESEM. From AFM, the mean diameter for CNPs was 38.6 ± 3.6 nm The CNPs were spherical in shape, homogenously scattered, less agglomerate, porous with rough surfaces. The size and morphology of the CNPs from blood cockle shells were suitable for transport carrier in situ bone infection, according to the results.

Synthesis and characterization of bio-nanocomposite based on chitosan and CaCO3 nanoparticles for heavy metals removal

Water is a vital component of life; therefore, it is critical to have access to pure water for various life-sustaining activities including agriculture and human consumption. An eco-friendly nanocomposite based on chitosan (Cs) and nanomaterials (CaCO3-NPs) were combined to amalgamate the advantages of biopolymers and nanomaterials to overcome the problems of instability, poor mechanical properties, and low removal percentage of biopolymers. The as-prepared samples were characterized and were used for the removal of heavy metal from wastewater. X-ray diffractometer, Fourier transform infrared spectroscopy, and transmission electron microscope were used to distinguish the prepared absorbents. The absorption of the heavy metals by as-prepared samples was examined at different conditions. The kinetic and isotherm models of the adsorption process were also studied. The data showed that the removal percentages of Cd, Cu, Pb, Zn, Cr and Ni by the composite were 98.0, 94.8, 99.0, 97.9, 97.4 and 98.3 %, respectively. The kinetic and isothermal studies showed that the absorption of these metal ions by the samples obeyed a pseudo-second-order mechanism and Langmuir isotherm model, respectively. In addition, the maximum adsorption capacities of Cd, Cu, Pb, Zn, Cr, and Ni ions by as-prepared nanocomposite were 83.33, 47.84, 98.03, 89.28, 62.11, and 63.69 mg/g, respectively.

Of Glasses and Crystals: Mitigating the Deactivation of CaO-Based CO2 Sorbents through Calcium Aluminosilicates.

CaO-based sorbents are cost-efficient materials for high-temperature CO2 capture, yet they rapidly deactivate over carbonation-regeneration cycles due to sintering, hindering their utilization at the industrial scale. Morphological stabilizers such as Al2O3 or SiO2 (e.g., introduced via impregnation) can improve sintering resistance, but the sorbents still deactivate through the formation of mixed oxide phases and phase segregation, rendering the stabilization inefficient. Here, we introduce a strategy to mitigate these deactivation mechanisms by applying (Al,Si)Ox overcoats via atomic layer deposition onto CaCO3 nanoparticles and benchmark the CO2 uptake of the resulting sorbent after 10 carbonation-regeneration cycles against sorbents with optimized overcoats of only alumina/silica (+25%) and unstabilized CaCO3 nanoparticles (+55%). 27Al and 29Si NMR studies reveal that the improved CO2 uptake and structural stability of sorbents with (Al,Si)Ox overcoats is linked to the formation of glassy calcium aluminosilicate phases (Ca,Al,Si)Ox that prevent sintering and phase segregation, probably due to a slower self-diffusion of cations in the glassy phases, reducing in turn the formation of CO2 capture-inactive Ca-containing mixed oxides. This strategy provides a roadmap for the design of more efficient CaO-based sorbents using glassy stabilizers.

Producing amorphous calcium carbonate using waste Ca-rich solution generated through the bio-leaching of slag

This study presents a new method for treating waste Ca-rich solutions (WCS), from which amorphous calcium carbonate (ACC) nanoparticles, an industrial product in high demand, are produced. The distinctive feature of this method is the use of tannic acid (TA) as a surfactant, employing a CO2 bubbling method under ambient conditions. By modulating the concentration of TA, the morphology and crystallization of the generated CaCO3 nanoparticles can be effectively controlled. Experimental results reveal that with increasing TA dosage, the crystallinity of CaCO3 decreases until an amorphous phase is obtained. The crystallization of ACC in solution was completely inhibited when TA was added at a concentration of more than 1%. Therefore, the proposed method provides a new strategy for the efficient preparation of ACC from WCS.

Simulation of the effect of nano-CaCO3 agglomeration on the hydration process and microstructural evolution of cement paste

In this study, three-dimensional simulations of cement hydration are conducted to investigate the effect of nano-CaCO3 (NC) agglomeration on the hydration process and microstructural evolution of cement pastes (CPs). Few experimental studies have reported on the effect of NC agglomeration on the properties of CPs because the degree of NC agglomeration is difficult to control in experiments. Herein, NC agglomeration was first investigated in a simulation by assigning different contents of NC in water-filled voxels in a three-dimensional cement hydration and microstructure development model (CEMHYD3D). CPs containing 3 wt% NC with a water-to-cement ratio (w/c) of 0.3 were considered in the simulation. Four levels (1, 2, 3, and 4) of NC agglomeration were investigated by assigning 8.5, 13.7, 19.8, and 27 vol% of NC in a C–H voxel, respectively. Agglomeration level 0 refers to the condition in which no NC particles are deposited in a water-filled voxel. An isothermal calorimetry test was conducted to validate the simulation results obtained for plain CPs. A comparison of experimental data and simulation results in terms of heat flow rate and heat formation revealed that level 3 showed better agreement than the other levels. The effect of NC agglomeration on cement hydration was more evident in the early stages of the process than in the later stages. Lower levels of agglomeration resulted in a faster hydration rate, a higher degree of hydration (DOH), and higher C–S–H and CH contents at an early age. However, the addition of NC particles did not result in an increase in ultimate DOH.

Multifunctional CaCO3@Cur@QTX125@HA nanoparticles for effectively inhibiting growth of colorectal cancer cells

Colorectal cancer (CRC) is a major cause of cancer-related deaths in humans, and effective treatments are still needed in clinical practice. Despite significant developments in anticancer drugs and inhibitors, their poor stability, water solubility, and cellular membrane permeability limit their therapeutic efficacy. To address these issues, multifunctional CaCO3 nanoparticles loaded with Curcumin (Cur) and protein deacetylase (HDAC) inhibitor QTX125, and coated with hyaluronic acid (HA) (CaCO3@Cur@QTX125@HA), were prepared through a one-step gas diffusion strategy. Dynamic light scattering (DLS), transmission electron microscopy (TEM), and scanning electron microscopy (SEM) showed that CaCO3@Cur@QTX125@HA nanoparticles have uniform spherical morphology and elemental distribution, with diameters around 450 nm and a Zeta potential of − 8.11 mV. The controlled release of Cur from the nanoparticles was observed over time periods of 48 h. Cellular uptake showed that CaCO3@Cur@QTX125@HA nanoparticles were efficiently taken up by cancer cells and significantly inhibited their growth. Importantly, CaCO3@Cur@QTX125@HA nanoparticles showed specific inhibitory effects on CRC cell growth. Encouragingly, CaCO3@Cur@QTX125@HA nanoparticles successfully internalized into CRC patient-derived organoid (PDO) models and induced apoptosis of tumor cells. The multifunctional CaCO3@Cur@QTX125@HA nanoparticles hold promise for the treatment of CRC.

Physico-mechanical properties of gamma irradiated polypropylene/ ethylene propylene diene monomer/CaCO3 nanocomposites

ABSTRACT The effect of gamma irradiation on the physico-mechanical properties of nanocomposites-based ethylene propylene diene monomer (EPDM) rubber and polypropylene (PP) blends reinforced with CaCO3 nanoparticles was studied. The nanocomposites were characterized in terms of mechanical, thermal and morphological properties and XRD diffraction. The results indicated, generally, that the elongation at break (E%) was found to decrease by increasing the ratio of PP in the nanocomposite blends and the irradiation dose. The E% values of unirradiated pure EPDM and PP polymers were 1785.0 and 125.0%, respectively. The nanocomposite EPDM/PP (50%)/CaCO3 irradiated to 60 kGy displayed the best properties.

Dual-Wavelength Passively Q-Switched Erbium-Doped Fiber Laser Incorporating Calcium Carbonate Nanoparticles as Saturable Absorber

This study experimentally demonstrates the operation of a dual-wavelength passively Q-switched erbium-doped fiber laser that incorporates CaCO3 nanoparticles as a saturable absorber (SA). The SA was prepared by using the drop-casting method, wherein CaCO3 nanoparticles were embedded in a polyvinyl alcohol (PVA) polymer to form a CaCO3/PVA film SA. The film was integrated into a ring laser cavity with a 976 nm pump to generate Q-switched pulses. The properties of the SA were examined experimentally, and its modulation depth is approximately 47%. As the pump power increased from 180 mW to 270 mW and the pulse repetition rate increased from 12.67 kHz to 21.3 kHz, the corresponding pulse width decreased from 35.27 μs to 18.74 μs. The signal-to-noise ratio was approximately 25 dB, highlighting the laser’s stability. The results indicate that the proposed CaCO3/PVA SA is suitable for realizing portable Q-switched lasers.

Surface tension, wettability and tribological properties of a low viscosity oil using CaCO3 and CeF3 nanoparticles as additives

The rise of the electric vehicles as a more sustainable transport alternative makes it necessary to study new transmission fluids that adapt to their needs and improve their efficiency. The thermophysical properties (contact angle, surface tension and rheology) and tribological properties (friction and wear) of potential PAO8 transmission nanofluids using CaCO3 and CeF3 nanoparticles as additives are evaluated at mass concentrations of 0.05, 0.10, 0.15 and 0.20 wt%. Low contact angle and surface tension values are obtained, indicating good wettability. When the nanoparticles are used as PAO8 additives, small reductions in surface tension are achieved, but no differences in contact angle are observed. All nanolubricants and base oil exhibit Newtonian behavior. Concerning the tribological behavior, reductions in the friction coefficient are achieved for both types of nanoparticles, with the largest reductions comparing to PAO8 base oil being 13 % and 10 % for nanolubricants containing 0.05 wt% CaCO3 and 0.10 wt% CeF3 nanoparticles (NPs), respectively. In terms of antiwear performance, maximum reductions are obtained for the CaCO3 nanolubricant of 28 % (0.15 wt%), 41 % (0.10 wt%) and 59 % (0.15 wt%) and for the CeF3 nanolubricant of 19 % (0.20 wt%), 53 % (0.10 wt%) and 58 % (0.20 wt%) for the parameters of diameter, depth, and area of the worn track, respectively. Through Raman microscopy, the tribological mechanisms of tribofilm formation, repairing, and rolling can be proposed. A discontinuous tribofilm formed by the CaCO3 and CeF3 nanoparticles reduces the contact area between the two surfaces protecting them.

A tumor microenvironment responsive titanium-based nanosonosensitizer for combination sonodynamic-immunotherapy with calcium ion overload

Ultrasound (US)-triggered sonodynamic therapy (SDT) has become a promising method and has attracted considerable attention for cancer therapy due to its high accuracy, deep tissue penetration, and few side effects. However, the therapeutic efficacy of SDT is limited by the hypoxic tumor microenvironment (TME) and the low quantum yield of sonosensitizers. Immunogenic cell death (ICD) induced by calcium ion overload has attracted widespread attention because it can trigger antitumor immune responses and reconstitute tumor immune microenvironment (TIM).In this study, a TME-responsive CaCO3@Pt-TiO2 nanocomposite (CaPT) was engineered, which combined platinum (Pt) nanoparticles and CaCO3 nanoparticles to amplify oxidative stress in cancer cells for cancer sonodynamic immunotherapy. The Pt nanoparticles not only enhanced the reactive oxygen species (ROS) quantum yield of TiO2 during SDT but also catalyzed the decomposition of H2O2 to overcome tumor hypoxia. The CaCO3@Pt-TiO2 nanocomposite responded to the TME and released a large amount of Ca2+, which amplified oxidative stress and triggered robust ICD activation. This process greatly contributed to inflammatory cell infiltration and shifted the TIM from cold to hot. The experimental results confirmed and demonstrated the synergistic therapeutic effects of sonodynamic-immunotherapy in vitro and in vivo. The antitumor mechanisms of sonodynamic immunotherapy were demonstrated by RNA sequencing. This study paves the way for Ti-based nanosensitizers, providing a novel strategy for sonodynamic-cooperated immunotherapy.

Insight into biomolecular interaction-based non-classical crystallization of bacterial biocement.

In an attempt to draw a correlation between calcium carbonate (CaCO3) precipitation and biomacromolecules such as extracellular polymeric substances and enzyme activity in biomineralizing microbe, this report aims to elucidate the ureolytic and ammonification route in Paenibacillus alkaliterrae to explore the possible role of organic biomolecule(s) present on cell surface in mediating nucleation and crystallization of biogenic CaCO3. After 168h of biomineralization in ureolysis and ammonification, 2.2g/l and 0.87g/l of CaCO3 precipitates were obtained, respectively. The highest carbonic anhydrase activity (31.8 µmoles/min/ml) was evidenced in ammonification as opposed to ureolysis (24.8 µmoles/min/ml). Highest urease activity reached up to 9.26 µmoles/min/ml in ureolytic pathway. Extracellular polymeric substances such as polysaccharides and proteins were found to have a vital role not only in the nucleation and crystal growth but also in addition direct polymorphic fate of CaCO3 nanoparticles. EPS production was higher during ammonification (3.1mg/ml) than in ureolysis (0.72mg/ml). CaCO3 nanoparticle-associated proteins were found to be 0.82mg/ml in ureolysis and 0.56mg/ml in ammonification. After 30days of biomineralization, all the polymorphic forms stabilized to calcite in ureolysis but in ammonification vaterite predominated. In our study, we showed that organic template-mediated prokaryotic biomineralization follows the non-classical nucleation and varying proportions of these organic components causes selective polymorphism of CaCO3 nanoparticles. Overall, the findings are expected to further the fundamental understanding of enzymes, EPS-driven non-classical nucleation of CaCO3, and we foresee the design of fit-for-purpose futuristic biominerals arising from such renewed understanding of biomineralization. KEY POINTS: • Organic-inorganic interface of cell surface promote crystallization of biominerals • Carbohydrate and proteins in the interface results selective polymorphism of CaCO3 • Calcite stabilized at 30days in ureolysis, vaterite-calcite mix in ammonification.

Biosynthesis of magnesium oxide and calcium carbonate nanoparticles using Moringa oleifera extract and their effectiveness on the growth, yield and photosynthetic performance of groundnut (Arachis hypogaea L.) genotypes

Small-scale crop production has been significantly impacted by the heavy price, limited supply, and frequent shortage of inorganic fertilisers, which is partly attributable to the Covid-19 pandemic outbreak and led to rising oil and food prices. Thus, integrating environmentally friendly agricultural practices that can improve crop productivity and advance the sustainability of agricultural cropping systems is critical.This study synthesized and characterised MgO and CaCO3Moringa oleifera nanoparticles and assessed their effects on groundnut genotypes. The effect of biosynthesized MgO and CaCO3 nanoparticles using Moringa oleifera extract on the growth and yield of groundnut genotypes exposed to different concentrations of 50, 100 and 200 mg/L was examined. The experiment was carried laid out in a 3 × 8 factorial completely randomized design (CRD) with eight replicates per treatment. Each plant was sprayed with 5 ml of the solution crystalline size of the MgO and CaCO3 nanoparticles 2.48 nm and 10.30 nm, respectively. Foliar application of nanoparticle treatments was applied weekly except for the negative control. The collected data were subjected to a two-way analysis of variance (ANOVA). Mean separations were done using Tukey's Honest Significant Difference (HSD) at P < 0.05.The findings demonstrated that foliar application of MgO and CaCO3 nanoparticles positively affected groundnut biomass production. The results further revealed that the concentration of 50 mg/L of MgO and 100 mg/L of CaCO3 considerably improved groundnut plant growth, yield, and nodulation in comparison with other treatments. There is a great deal of evidence signifying that foliar applications of 50 mg/L of MgO 100 mg/L CaCO3 contributed greatly to plant growth and crop production. Therefore, 50 mg/L of MgO and 100 mg/L CaCO3 nanoparticles foliar application could be recommended as nano-fertilisers application rate for groundnut production.

Preparation of polystyrene/EVA/CaCO3 microspheres using a novel one-pot method via a phase inversion emulsion process

The polymer/nano-inorganics composite microsphere possesses excellent application prospects, but it is difficult to resolve the problem of the aggregation of nano-inorganic particles in polymer and the affinity between inorganics and polymer matrix. In this study, the preparation and characterization of polystyrene (PS)/ethylene vinyl acetate copolymer (EVA)/CaCO3 microspheres fabricated via a novel phase inversion emulsion process are described. By this one-pot method, the PS/EVA/CaCO3 microspheres are obtained by firstly converting styrene monomer containing EVA and nano CaCO3 into droplets dispersed in water with help of emulsifiers and a following polymerization. Because the inorganic nanoparticles are ultrasonically dispersed in liquid monomer mixture before the polymerization, the aggregation of nano-inorganic particles could be prevented to a great extent. The EVA is designed to enhance toughness of polystyrene matrix and increase the affinity between polymer and inorganic particles. The morphological structure of PS/EVA/CaCO3 microspheres is that nano CaCO3 particles are embedded both in the interior and on the surface of the microspheres. The micro-sized PS/EVA/CaCO3 microspheres showed a significantly improved mechanical property and a better heat resistance. This technique also offers the possibility for fabricating many kinds of new and useful polymer/inorganic microspheres with tailored performance by using special monomers and inorganic particles.

Immunostimulant Hydrogel-Guided Tumor Microenvironment Reprogramming to Efficiently Potentiate Macrophage-Mediated Cellular Phagocytosis for Systemic Cancer Immunotherapy.

Macrophage-mediated cellular phagocytosis (MMCP) plays a critical role in conducting antitumor immunotherapy but is usually impaired by the intrinsic phagocytosis evading ability of tumor cells and the immunosuppressive tumor microenvironment (TME). Herein, a MMCP-boosting hydrogel (TCCaGM) was elaborately engineered by encapsulating granulocyte-macrophage colony-stimulating factor (GM-CSF) and a therapeutic nanoplatform (TCCaN) that preloaded with the tunicamycin (Tuni) and catalase (CAT) with the assistance of CaCO3 nanoparticles (NPs). Strikingly, the hypoxic/acidic TME was efficiently alleviated by the engineered hydrogel, "eat me" signal calreticulin (CRT) was upregulated, while the "don't eat me" signal CD47 was downregulated on tumor cells, and the infiltrated DCs were recruited and activated, all of which contributed to boosting the macrophage-mediated phagocytosis and initiating tumor-specific CD8+ T cells responses. Meanwhile, the remodeled TME was beneficial to accelerate the polarization of tumor-associated macrophages (TAMs) to the antitumoral M1-like phenotype, further heightening tumoricidal immunity. With the combination of PD-1 antibody (αPD-1), the designed hydrogel significantly heightened systemic antitumor immune responses and long-term immunological effects to control the development of primary and distant tumors as well as suppress tumor metastasis and recurrence, which established an optimal strategy for high-performance antitumor immunotherapy.

Research on performance monitoring of binary nano modified concrete based on temperature variation

The use of concrete is widespread, but it poses challenges due to its high consumption of Earth's raw resources and difficulties in recycling and reclamation. Today, the pressing climate issues, including global warming and the emergence of a complex climate, continue to test cement-based polymers in the civil engineering industry. As a result, there is a growing demand for higher performance, renewable resources, and reduced carbon dioxide production, leading to a shift in the traditional industrial revolution. Composite nano concrete has emerged as an effective solution to address the challenges related to concrete mechanics and durability, aligning with the principles of sustainable development goals. The research focuses on utilizing composite nano-modified concrete to enhance the life cycle of structures. This nano-modified concrete incorporates Nano-SiO₂ (NS) and Nano-CaCO3 (NC) particles to create a new composite nano-concrete structure called NSC concrete. The research paper explores different dosages of composite nano concrete, specifically 2.5 %, 3.0 %, and 3.5 %, denoted as NSC25, NSC30, and NSC35, respectively. It examines the performance of the composite nano concrete under various temperature conditions, including 25 °C, 200 °C, 400 °C, and 600 °C, to simulate real-world scenarios and evaluate its value-based applications. The article analyzes multiple aspects, including mechanical properties, durability, visual appearance, and economic benefits of composite nano concrete. It also assesses NSC concrete's temperature dissipation capacity and insulation level and investigates the interfacial transition zone influenced by nanoparticles and temperature. The results indicate that the new composite nano concrete retains substantial enhancements in mechanical properties, with a maximum increase of 1.22 % in splitting strength and up to 45.69 % improvement in flexural strength at a temperature of 600 °C. Additionally, it demonstrates commendable durability and economic efficiency

In Vivo Immune Adjuvant Effects of CaCO3 Nanoparticles through Intracellular Ca2+ Concentration Regulation.

Calcium (Ca) is a vital component of the human body and plays a crucial role in intracellular signaling and regulation as a second messenger. Recent studies have shown that changes in intracellular Ca2+ concentration can influence immune cell function. In this study, we developed calcium carbonate nanoparticles (CaNPs) of various sizes using a Nanosystem Platform to modulate intracellular Ca2+ concentration in vitro and in vivo. Our findings demonstrate that intravenous administration of CaNPs led to changes in the number and ratio of immune cells in the spleen and stimulated the activation of dendritic cells (DCs) and macrophages. Notably, CaNPs exhibited strong adjuvant properties in the absence of antigenic stimuli. These results indicate that CaNPs have the potential to regulate immune cell function by modulating Ca2+ concentrations, offering a novel approach for disease prevention and treatment in combination with antigens or drugs. Overall, our study emphasizes the importance of modulating intracellular Ca2+ concentration as a means of regulating immune cell function.

Layer-by-layer coated calcium carbonate nanoparticles for targeting breast cancer cells

Breast cancer is resistant to conventional treatments due to the specific tumour microenvironment, the associated acidic pH and the overexpression of receptors that enhance cells tumorigenicity. Herein, we optimized the synthesis of acidic resorbable calcium carbonate (CaCO3) nanoparticles and the encapsulation of a low molecular weight model molecule (Rhodamine). The addition of ethylene glycol during the synthetic process resulted in a particle size decrease: we obtained homogeneous CaCO3 particles with an average size of 564 nm. Their negative charge enabled the assembly of layer-by-layer (LbL) coatings with surface-exposed hyaluronic acid (HA), a ligand of tumour-associated receptor CD44. The coating decreased Rhodamine release by two-fold compared to uncoated nanoparticles. We demonstrated the effect of nanoparticles on two breast cancer cell lines with different aggressiveness – SK-BR-3 and the more aggressive MDA-MB-231 – and compared them with the normal breast cell line MCF10A. CaCO3 nanoparticles (coated and uncoated) significantly decreased the metabolic activity of the breast cancer cells. The interactions between LbL-coated nanoparticles and cells depended on HA expression on the cell surface: more particles were observed on the surface of MDA-MB-231 cells, which had the thickest endogenous HA coating. We concluded that CaCO3 nanoparticles are potential candidates to carry low molecular weight chemotherapeutics and deliver them to aggressive breast cancer sites with an HA-abundant pericellular matrix.