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• New surface active Tetracationic AImILs highly adsorbed 2.8 mol of CO 2 /mol. • Amphiphilic thermal stable porous spheres of CaCO 3 NPs prepared from CO 2. • Highly dispersed CaCO 3 NPs in seawater used as additive for WBD fluids. • CaCO 3 @ HDAP-ImA and CaCO 3 @DDAP-ImA particles employed as a viscosifier and/or filtrate control agent in bentonite- based WBMs. Conversion and capture of carbon pollutants based on carbon dioxide to valuable green oil-field chemicals are target all over the world for controlling the global warming. The present article used new room temperature amphiphilic imidazolium ionic liquids with superior surface activity in the aqueous solutions to convert carbon dioxide gas to superior amphiphilic calcium carbonate nanoparticles. In this respect, tetra-cationic ionic liquids 2-(4-dodecyldimethylamino) phenyl)-1,3-bis (3-dodecyldimethylammnonio) propyl) bromide-1-H-imidazol-3-ium acetate and 2-(4-hexyldimethylamino) phenyl)-1,3-bis(3-hexcyldimethylammnonio) propyl) bromide-1 H-imidazol-3-ium acetate were prepared. Their chemical structures, thermal as well as their carbon dioxide absorption/ desorption characteristics were evaluated. They were used as solvent and capping agent to synthesize calcium carbonate nanoparticles with controlled crystalline lattice, sizes, thermal properties and spherical surface morphologies. The prepared calcium carbonate nanoparticles were used as additives for the commercial water based drilling mud to improve their filter lose and rheology. The data confirm that the lower concentrations of 2-(4-dodecyldimethylamino) phenyl)-1,3-bis (3-dodecyldimethylammnonio) propyl) bromide-1-H-imidazol-3-ium acetate achieved lower seawater filter lose and improved viscosities. [ABSTRACT FROM AUTHOR]

Abstract This study aimed to design sustained released biodegradable calcium carbonate nanoparticles loaded with chlorhexidine (CHX-loaded NPs) and to investigate the early osteogenic differentiation and antimicrobial effects on the important bacteria involved in infections of dental implants. The microemulsion method was used to prepare the calcium carbonate nanoparticles loaded with chlorhexidine. The prepared nanoparticles were characterized using conventional methods. The release pattern determination and the biodegradation test were performed for the prepared nanoparticles. For the early osteogenic differentiation test of the prepared nanoparticles, alkaline phosphatase (ALP) activity was detected in human dental pulp stem cells (HDPSCs). The antimicrobial effects of the nanoparticles were evaluated against Escherichia coli, Streptococcus mutans, Enterococcus faecalis, Staphylococcus aureus, and Pseudomonas aeruginosa. The sizes of free calcium carbonate nanoparticles and CHX-loaded NPs were 105 ± 1.63 and 118 ± 1.47 nm and their zeta potentials were − 27 and − 36, respectively. A 50% degradation of nanoparticles was achieved after 100 days. These nanoparticles showed a two-stage sustained release pattern in vitro. Microscopic images revealed that the morphology of free calcium carbonate nanoparticles primarily took on a spherical calcite form, while CHX-loaded NPs predominantly exhibited a cauliflower-like vaterite polymorph. The nanoparticles increased the activity of ALP in cells in two weeks significantly (p

This study aimed to design sustained released biodegradable calcium carbonate nanoparticles loaded with chlorhexidine (CHX-loaded NPs) and to investigate the early osteogenic differentiation and antimicrobial effects on the important bacteria involved in infections of dental implants. The microemulsion method was used to prepare the calcium carbonate nanoparticles loaded with chlorhexidine. The prepared nanoparticles were characterized using conventional methods. The release pattern determination and the biodegradation test were performed for the prepared nanoparticles. For the early osteogenic differentiation test of the prepared nanoparticles, alkaline phosphatase (ALP) activity was detected in human dental pulp stem cells (HDPSCs). The antimicrobial effects of the nanoparticles were evaluated against Escherichia coli, Streptococcus mutans, Enterococcus faecalis, Staphylococcus aureus, and Pseudomonas aeruginosa. The sizes of free calcium carbonate nanoparticles and CHX-loaded NPs were 105 ± 1.63 and 118 ± 1.47 nm and their zeta potentials were − 27 and − 36, respectively. A 50% degradation of nanoparticles was achieved after 100 days. These nanoparticles showed a two-stage sustained release pattern in vitro. Microscopic images revealed that the morphology of free calcium carbonate nanoparticles primarily took on a spherical calcite form, while CHX-loaded NPs predominantly exhibited a cauliflower-like vaterite polymorph. The nanoparticles increased the activity of ALP in cells in two weeks significantly (p < 0.05). Antimicrobial and antibiofilm results showed an efficient effect of the prepared nanoparticle against the studied bacteria. Calcium carbonate nanoparticles are an efficient multifunctional vector for chlorhexidine and can be used as a bioactive antibacterial agent against various oral microorganisms to prevent implant infections. [ABSTRACT FROM AUTHOR]

Biological composites such as bone, nacre, and teeth show excellent mechanical efficiency because of the incorporation of biominerals into the organic matrix at the nanoscale, leading to hierarchical composite structures. Adding a large volume of ceramic nanoparticles into an organic molecular network uniformly has been a challenge in engineering applications. However, in natural organisms, biominerals grow inside organic fibers, such as chitin and collagen, forming perfect ceramic/polymer composites spontaneously via biomineralization processes. Inspired from these processes, the in situ growth of calcium carbonate nanoparticles inside the chitosan network to form ceramic composites was proposed in the current work. The crystal growth of CaCO3 nanoparticles in the chitosan matrix as a function of time was investigated. A weight percentage of ~35 wt% CaCO3 composite was realized, resembling the high weight percentage of mineral phase in bones. Scanning and transmission electron microscopy indicated the integration of CaCO3 nanocrystals with chitosan macromolecules. By growing CaCO3 minerals inside the chitosan matrix, the elastic modulus and tensile strength increases by ~110% and ~90%, respectively. The in situ crystal growth strategy was also demonstrated in organic frameworks prepared via 3D printing, indicating the potential of fabricating ceramic/polymer composites with complicated structures, and further applications in tissue engineering. [ABSTRACT FROM AUTHOR]

Today, the rise of opportunistic infections and their resistance to current antifungal drugs has led to the inevitable need to produce effective antimicrobials at a reasonable cost. This study aimed at producing a calcium carbonate/cobalt oxide nanocomposite with the most excellent antifungal activity against Candida albicans (C. albicans). Thus, nine experimental designs using the Taguchi technique were utilized to discover the greatest combination of parameters for antifungal activity. The colony‐forming unit (CFU) method was used to test the produced nanocomposites' antifungal properties against C. albicans. The results indicated that the synthesized nanocomposite in optimal conditions (20 mg/mL of calcium carbonate, 3 mg/mL of cobalt oxide, and 90 min of stirring time) could inhibit the growth of C. albicans by more than 74%. Various analyses were applied to determine the structural properties of the calcium carbonate/cobalt oxide nanocomposite, and its constituents revealed the fabricated nanocomposite's desirable properties. In the study, the nanocomposite was an efficient antifungal agent that might be employed in various fields, including medicine, dentistry, and life sciences. [ABSTRACT FROM AUTHOR]

Formation water scale blocks pipelines and results in oil/gas production decreasing and energy consumption increasing. Many methods have been developed to inhibit scale formation. However, these previous methods are limited by their complications and low efficiency. A new method is proposed in this paper that uses the scale in formation water as a nanomaterial to improve oil recovery via controlling particle size. A series of ligands were synthesized and characterized. Micrometer-CaCO3 was formed and accumulated to form scale of a large size under uncontrolled conditions. The tetradentate ligands (L4) exhibited an excellent capturing yield of Ca2+ (87%). The particle size was very small, but they accumulated to form large particles (approximately 1300 nm) in the presence of Na2CO3. The size of the CaCO3 could be further controlled by poly(aspartic acid) to form sizes of about 700 nm. The flooding test showed that this material effectively improved oil recovery from 55.2% without nano CaCO3 to 61.5% with nano CaCO3. This paves a new pathway for the utilization of Ca2+ in formation water. [ABSTRACT FROM AUTHOR]

Yurou Shi,1,2,&ast; Yingjie Zhang,1,&ast; Yaxuan Zhang,2 Jiali Yao,2 Junping Guo,3 Xiaoling Xu,2 Lijun Wang1 1Geriatric Medicine Center, Department of Endocrinology, Zhejiang Provincial People’s Hospital (Affiliated People’s Hospital), Hangzhou Medical College, Hangzhou, Zhejiang, 310015, People’s Republic of China; 2Shulan International Medical College, Zhejiang Shuren University, Hangzhou, 310015, People’s Republic of China; 3Rainbowfish Rehabilitation and Nursing School, Hangzhou Vocational & Technical College, Hangzhou, 310018, People’s Republic of China&ast;These authors contributed equally to this workCorrespondence: Xiaoling Xu, Shulan International Medical College, Zhejiang Shuren University, 8 Shuren Street, Hangzhou, 310015, People’s Republic of China, Email ziyao1988@zju.edu.cn Lijun Wang, Geriatric Medicine Center, Department of Endocrinology, Zhejiang Provincial People’s Hospital, No. 158 Shangtang Road, Hangzhou, Zhejiang, 310015, People’s Republic of China, Email wanglijun@hmc.edu.cnAbstract: Aging is an inevitable process in the human body, and cellular senescence refers to irreversible cell cycle arrest caused by external aging-promoting mechanisms. Moreover, as age increases, the accumulation of senescent cells limits both the health of the body and lifespan and even accelerates the occurrence and progression of age-related diseases. Therefore, it is crucial to delay the periodic irreversible arrest and continuous accumulation of senescent cells to address the issue of aging. The fundamental solution is targeted therapy focused on eliminating senescent cells or reducing the senescence-associated secretory phenotype. Over the past few decades, the remarkable development of nanomaterials has revolutionized clinical drug delivery pathways. Their unique optical, magnetic, and electrical properties effectively compensate for the shortcomings of traditional drugs, such as low stability and short half-life, thereby maximizing the bioavailability and minimizing the toxicity of drug delivery. This article provides an overview of how nanomedicine systems control drug release and achieve effective diagnosis. By presenting and analyzing recent advances in nanotherapy for targeting senescent cells, the underlying mechanisms of nanomedicine for senolytic and senomorphic therapy are clarified, providing great potential for targeting senescent cells. Keywords: senescent cells, calcium carbonate nanoparticles, liposomes, nanoemulsions, mesoporous silica nanoparticles

In this study, polyethylene (PE) was used as the raw material, and polyhydroxyalkanoate (PHA), modified nano-CaCO3 and bagasse fiber(BF) were used as the composite fillers, and the nano-CaCO3/BF/PHA/PE composites were prepared by melt extrusion and injection molding. The effects of the optimal ratios of PHA, modified nano-CaCO3 and BF and their contents on the internal structure and properties of the composites were investigated by mechanical property tests, Fourier transform infrared spectroscopy (FTIR) analysis, thermogravimetric (TG) analysis, scanning electron microscopy (SEM) and other characterization methods. The results show that with 5% PHA, 5% BF, and 5% nano-CaCO3, the mechanical properties of the composites were optimal at 12.9 MPa, and the maximum thermal decomposition temperature of the nano-CaCO3/BF/PHA/PE composites reached 437 °C at this ratio, which was higher than the thermal decomposition temperature (453 °C) of the composites before modification. The study provides ideas for the green development of degradable polymer materials. [ABSTRACT FROM AUTHOR]

Calcium carbonate nanoparticles (CaCO3) have been found to exhibit unique properties that show their potential to be used in various therapies. Green synthesis of CaCO3 has been progressively gaining ac-ceptance due to its cost-effectiveness and energy-efficient nature. In the current study, different extracts of Ailanthus altissima were used to synthesize the calcium carbonate nanoparticles the synthesis and characterization of CCNPs were confirmed by using Fourier Transform Infra-Red spectroscopy, UV-Vis spectroscopy, and Scanning Electron Microscopy (SEM). The antioxidant activities (hydrogen peroxide, phosphomolydbenum, and ferric reducing) of calcium carbonate nanoparticles were affirmed by a good range of percentages of inhibition against free radical scavenging. The antidebate assays of CCNPs were observed by in-vitro and in silico approaches in a range at various concentrations while maximum inhibition occurred. In conclusion, the current study depicted that conjugated CaCO3 with A. altissima has a good potential to cure oxidative stress and Type II diabetes and could be used in the future as biogenic nanomedicine for the treatment of other metabolic diseases. [ABSTRACT FROM AUTHOR]

Highly ordered porous structures of PLA composite films can be designed with the addition of calcium carbonate nanoparticles (CCN) in polymeric film formation using the breath figure (BF) technique at controlled humidity. Both 2D and 3D monodispersed honeycomb-like porous structures of the PLA composite films are achieved by the adding CCN at the concentration of up to 1.00 phr, whereas hierarchically multiscale porous structures of the PLA/CCN films are obtained when the CCN concentration in the composites increases to more than 1.00 phr. These structures can be fabricated due to three mechanisms: water absorption and condensation, nano-Pickering emulsion, and capillary flow by self-assembly of the nanoparticles. Moreover, the nano effects of CCN on polymeric film fabrication are maximized by increasing the relative humidity to 90%, resulting in the formation of porous multilayers up to 95–120 μm in thickness. The application of the prepared porous composite films of PLA/CCN in the food and medical industries was illustrated. A model colorimetric sensor is made from PLA/CCN composite films enriched with bromothymol blue. The color of the films quickly changes from yellow to blue within 10 min after coming into contact with histamine, a representative gas generated from spoiled food.

Limited by low tumor immunogenicity and the immunosuppressive tumor microenvironment (TME), triple-negative breast cancer (TNBC) has been poorly responsive to immunotherapy so far. Herein, a Ca & Mn dual-ion hybrid nanostimulator (CMS) is constructed to enhance anti-tumor immunity through ferroptosis inducing and innate immunity awakening, which can serve as a ferroptosis inducer and immunoadjuvant for TNBC concurrently. On one hand, glutathione (GSH) depletion and reactive oxygen species (ROS) generation can be achieved due to the mixed valence state of Mn in CMS. On the other hand, as an exotic Ca2+ supplier, CMS causes mitochondrial Ca2+ overload, which further amplifies the oxidative stress. Significantly, tumor cells undergo ferroptosis because of the inactivation of glutathione peroxidase 4 (GPX4) and accumulation of lipid peroxidation (LPO). More impressively, CMS can act as an immunoadjuvant to awaken innate immunity by alleviating intra-tumor hypoxia and Mn2+-induced activation of the STING signaling pathway, which promotes polarization of tumor-associated macrophages (TAMs) and activation of dendritic cells (DCs) for antigen presentation and subsequent infiltration of tumor-specific cytotoxic T lymphocytes (CTLs) into tumor tissues. Taken together, this work demonstrates a novel strategy of simultaneously inducing ferroptosis and awakening innate immunity, offering a new perspective for effective tumor immunotherapy of TNBC.

Current highly integrated devices require heat interface materials with excellent heat conductivity. A simple approach was employed to synthesize thermally conductive and outstanding thermal stability nanocomposite. Calcium carbonate nanoparticles (nano CaCO 3) reinforced with reduced graphene oxide (rGO) nanoparticles (rGO/CaCO 3) are synthesized using a novel process, and the effect of rGO in CaCO 3 structure is examined by Field Emission Scanning Electron Microscope, X-ray diffraction, TGA-DTA, and thermal conductivity. The experimental results show that adding rGO resulted in higher crystallinity and thermal stability. As the wt.% of rGO increases from 1 to 5%, the crystallite size was suppressed by 21.06%, 27.39%, 32.48%, 41.5%, and 45.30%, respectively, compared to the pure nano-CaCO 3. Additionally, rGO enhances the thermal conductivity by 35.31% and thermal diffusivity to 1.834 mm2/s by adding 5% rGO. [ABSTRACT FROM AUTHOR]

[Display omitted] Hypothesis: Calcium carbonate (CaCO 3) nanoparticles could have great potential for contrast-enhanced ultrasound imaging (CEUS) due to their gas-generating properties and sensitivity to physiological conditions. However, the use of nano CaCO 3 for biomedical applications requires the assistance of stabilizers to control the size and avoid the fast dissolution/recrystallization of the particles when exposed to aqueous conditions. Experiments : Herein, we report the stabilization of nano CaCO 3 using lignin, and synthesized core–shell amorphous CaCO 3 -lignin nanoparticles (LigCC NPs) with a diameter below 100 nm. We have then investigated the echogenicity of the LigCC NPs by monitoring the consequent generation of contrast in vitro for 90 min in linear and non-linear B-mode imaging. Findings: This research explores how lignin type and structure affect stabilization efficiency, lignin structuration around CaCO 3 cores, and particle echogenicity. Interestingly, by employing lignin as the stabilizer, it becomes possible to maintain the echogenic properties of CaCO 3 , whereas the use of lipid coatings prevents the production of signal generation in ultrasound imaging. This work opens new avenue for CEUS imaging of the vascular and extravascular space using CaCO 3 , as it highlights the potential to generate contrast for extended durations at physiological pH by utilizing the amorphous phase of CaCO 3. [ABSTRACT FROM AUTHOR]

This paper firstly reports the size effect of typical micro‐ and nano‐ calcium carbonate additives on the friction properties of calcium sulfonate grease. The rheological and tribological performance of calcium sulfonate grease with typical micro‐ and nano‐ calcium carbonate additives were investigated at 30 or 80°C by Rheometer and Optimol SRV‐V tester. To its surprise, calcium sulfonate grease with 5% calcium carbonate microparticles behave remarkable lubrication performance than calcium sulfonate grease with 5% calcium carbonate nanoparticles under boundary lubrication condition according to the rheological analysis and tribological evaluation. The enhancement in excellence tribological performance can be attributed to the synergistic effect between calcium carbonate microparticles and calcium carbonate in thickener of calcium sulfonate grease. The thin film composed of CaCO3 and CaO on the worn surface generated by solid particles is conducive to reducing friction and wear. [ABSTRACT FROM AUTHOR]

Immune checkpoint blockade (ICB) therapy is a revolutionary approach to treat cancers, but still have limited clinical applications. Accumulating evidence pinpoints the immunosuppressive characteristics of the tumor microenvironment (TME) as one major obstacle. The TME, characterized by acidity, hypoxia and elevated ROS levels, exerts its detrimental effects on infiltrating anti-tumor immune cells. Here, we developed a TME-responsive and immunotherapeutic catalase-loaded calcium carbonate nanoparticles (termed as CAT@CaCO3 NPs) as the simple yet versatile multi-modulator for TME remodeling. CaCO3 NPs can consume protons in the acidic TME to normalize the TME pH. CAT catalyzed the decomposition of ROS and thus generated O2. The released Ca2+ led to Ca2+ overload in the tumor cells which then triggered the release of damage-associated molecular patterns (DAMP) signals to initiate anti-tumor immune responses, including tumor antigen presentation by dendritic cells. Meanwhile, CAT@CaCO3 NPs-induced immunosupportive TME also promoted the polarization of the M2 tumor-associated macrophages to the M1 phenotype, further enhancing tumor antigen presentation. Consequently, T cell-mediated anti-tumor responses were activated, the efficacy of which was further boosted by aPD-1 immune checkpoint blockade. Our study demonstrated that local treatment of CAT@CaCO3 NPs and aPD-1 combination can effectively evoke local and systemic anti-tumor immune responses, inhibiting the growth of treated tumors and distant diseases.

Biological composites such as bone, nacre, and teeth show excellent mechanical efficiency because of the incorporation of biominerals into the organic matrix at the nanoscale, leading to hierarchical composite structures. Adding a large volume of ceramic nanoparticles into an organic molecular network uniformly has been a challenge in engineering applications. However, in natural organisms, biominerals grow inside organic fibers, such as chitin and collagen, forming perfect ceramic/polymer composites spontaneously via biomineralization processes. Inspired from these processes, the in situ growth of calcium carbonate nanoparticles inside the chitosan network to form ceramic composites was proposed in the current work. The crystal growth of CaCO3 nanoparticles in the chitosan matrix as a function of time was investigated. A weight percentage of ~35 wt% CaCO3 composite was realized, resembling the high weight percentage of mineral phase in bones. Scanning and transmission electron microscopy indicated the integration of CaCO3 nanocrystals with chitosan macromolecules. By growing CaCO3 minerals inside the chitosan matrix, the elastic modulus and tensile strength increases by ~110% and ~90%, respectively. The in situ crystal growth strategy was also demonstrated in organic frameworks prepared via 3D printing, indicating the potential of fabricating ceramic/polymer composites with complicated structures, and further applications in tissue engineering.

Researchers have shown significant interest in the incorporation of nanoscale components into concrete, primarily driven by the unique properties exhibited by these nanoelements. A nanoparticle comprises numerous atoms arranged in a cluster ranging from 10 nm to 100 nm in size. The brittleness of foamed concrete (FC) can be effectively mitigated by incorporating nanoparticles, thereby improving its overall properties. The objective of this investigation is to analyze the effects of incorporating calcium carbonate nanoparticles (CCNPs) into FC on its mechanical and durability properties. FC had a 750 kg/m3 density, which was achieved using a binder-filler ratio of 1:1.5 and a water-to-binder ratio of 0.45. The CCNPs material exhibited a purity level of 99.5% and possessed a fixed grain size of 40 nm. A total of seven mixes were prepared, incorporating CCNPs in FC mixes at the specific weight fractions of 0% (control), 1%, 2%, 3%, 4%, 5%, and 6%. The properties that were assessed included the slump, bulk density, flexural strength, splitting tensile strength, compressive strength, permeable porosity, water absorption, drying shrinkage, softening coefficient, and microstructural characterization. The results suggested that incorporating CCNPs into FC enhanced its mechanical and durability properties, with the most optimal improvement observed at the CCNPs addition of 4%. In comparison to the control specimen, it was witnessed that specimens containing 4% CCNPs demonstrated remarkably higher capacities in the compressive, splitting tensile, and flexural tests, with the increases of 66%, 52%, and 59%, respectively. The addition of CCNPs resulted in an improvement in the FC porosity and water absorption. However, it also led to a decrease in the workability of the mixtures. Furthermore, the study provided the correlations between the compressive strength and splitting tensile strength, as well as the correlations between the compressive strength and flexural strength. In addition, an artificial neural network approach was employed, utilizing k-fold cross-validation, to predict the compressive strength. The confirmation of the property enhancement was made through the utilization of a scanning electron microscope.

The objective of this study is to harness the potential of biomineralization for the controlled fabrication of tetrahedral DNA (TDN)-mediated calcium carbonate (CaCO3) nanoparticles with applications in cancer therapy. While TDN has emerged as an efficient anti-cancer drug carrier, its inherent instability under physiological conditions poses challenges for sustained drug release. Biomineralization, known for its ability to maintain carrier morphology and stability in physiological environments, is leveraged in this research to enhance TDN's drug delivery capabilities. In this study, we successfully synthesized TDN-mediated CaCO3 nanoparticles through a biomineralization process, with comprehensive characterization utilizing TEM, SEM, AFM, and DLS techniques. The morphology and crystal phase of the resulting CaCO3 nanoparticles, ranging from 10 to 100 nm, are precisely controlled by the presence of TDN. Remarkably, the engineered nanoparticles demonstrated efficient loading and controlled delivery of the anti-cancer drug doxorubicin (Dox), suggesting their potential for cancer therapy. The TDN-CaCO3 nanoparticles exhibited notable attributes including high drug loading efficiency (42.2%), favorable biocompatibility, pH responsiveness, and minimal cytotoxicity. The findings of this study underscore the potential of TDN-CaCO3 nanoparticles as a promising therapeutic agent for safe and effective cancer treatment, offering new avenues for innovative and efficient drug delivery strategies in the future. [ABSTRACT FROM AUTHOR]

This research focuses on the investigation of cyclolinopeptide J (CLJ), a bioactive peptide naturally present in flaxseed, which loaded in porous calcium carbonate (CA) nanoparticles (JCA) to augment the effectiveness of CLJ on osteogenesis. The JCA was successfully synthesized with a high loading capacity (47.8 %) and encapsulation efficiency (95.6 %). Results showed that CLJ exerted an excellent osteogenic effect at 10 µM in MC3T3-E1 cells. CLJ and CA have been shown to activate osteogenic factors by modulating the Wnt/β-catenin and BMP/Smad signaling pathways. Furthermore, JCA treatment exhibited a remarkable ability to restore the intricate trabecular characteristics of bone in OVX-induced mice. The trabecular bone architecture observed in JCA-treated mice closely resembled that of healthy controls, indicating a substantial amelioration of osteoporotic bone loss. Our findings highlight the synergistic treatment of CLJ and CA in restoring bone integrity and structure and provide compelling evidence for the effectiveness of this novel functional supplement.

The use of nanoparticles (NPs) as delivery vehicles for multiple drugs is an intensively developing area. However, the success of NPs' accumulation in the tumor area for efficient tumor treatment has been recently questioned. Distribution of NPs in a laboratory animal is mainly related to the administration route of NPs and their physicochemical parameters, which significantly affect the delivery efficiency. In this work, we aim to compare the therapeutic efficiency and side effects of the delivery of multiple therapeutic agents with NPs by both intravenous and intratumoral injections. For this, we systematically developed universal nanosized carriers based on calcium carbonate (CaCO 3) NPs (< 100 nm) that were co-loaded with a photosensitizer (Chlorin e6, Ce6) and chemotherapeutic agent (doxorubicin, Dox) for combined chemo- and photodynamic therapy (PDT) of B16-F10 melanoma tumors. By performing intratumoral or intravenous injections of NPs, we observed different biodistribution profiles and tumor accumulation efficiencies. In particular, after intratumoral administration of NPs, they mostly remained in the tumors (> 97%); while for intravenous injection, the tumor accumulation of NPs was determined to be 8.67–12.4 ID/g%. Although the delivery efficiency of NPs (presented in ID/g%) in the tumor differs, we have developed an effective strategy for tumor inhibition based on combined chemo- and PDT by both intratumoral and intravenous injections of NPs. Notably, after the combined chemo- and PDT treatment with Ce6/Dox@CaCO 3 NPs, all B16-F10 melanoma tumors in mice shrank substantially, by approximately 94% for intratumoral injection and 71% for intravenous injection, which are higher values compared to mono-therapy. In addition, the CaCO 3 NPs showed negligible in vivo toxicity towards major organs such as the heart, lungs, liver, kidneys, and spleen. Thus, this work demonstrates a successful approach for the enhancement of NPs' efficiency in combined anti-tumor therapy. [Display omitted] [ABSTRACT FROM AUTHOR]

Tumor-associated macrophages (TAMs) are key contributors to tumor development, accelerated tumor invasion and metastasis, and induction of immunosuppression. Targeted delivery of immunomodulatory agents to promote polarization of TAMs may alleviate the immunosuppressive tumor microenvironment. Calcium carbonate nanoparticles (CCN), which exhibit excellent biocompatibility, pH sensitivity, and easy surface modification, have attracted substantial attention in targeted nano delivery. In this study, CCN were used as a matrix material to develop UNO-peptide-modified lipid CCN for targeted immunomodulation of TAMs by using the mannose receptor overexpressed on the surfaces of TAMs as targets. The preparation of CCN was optimized through single-factor testing with the gas diffusion method with the particle size as the index. The surface modification of CCN with UNO-peptide-modified phospholipids was performed, and its targeting effect on TAMs was investigated. The average particle size of the CCN and UNO-peptide-modified CCN was 144.5 ± 3.8 nm and 167.0 ± 1.3 nm, respectively. UNO-peptide-modified CCN entered TAMs via actively targeted uptake mediated by mannose receptors. Our results demonstrated that the developed UNO-peptide-modified CCN with controlled nano-size and excellent TAMs-targeting properties is a highly promising nanocarrier for targeted delivery of TAM immunomodulatory agents.

In this study, Gum Arabic natural polymer was used to green synthesize calcium carbonate nanoparticles (CaCO3-NPs). Synthesized CaCO3-NPs were identified using various analyses such as FTIR, XRD, FESEM, EDX, and UV–Vis. The UV spectrum of nanoparticles showed an absorption band at a wavelength of 320 nm. FTIR analysis also confirmed the synthesis of nanoparticles. XRD studies showed that CaCO3-NPs have a rhombohedral crystalline structure with space group R-3c and an average size of about 42 nm. FESEM images showed that CaCO3-NPs have cubic morphology and EDX results confirmed the presence of carbon, calcium, and oxygen elements. The synthesized CaCO3-NPs showed good photocatalytic activity to methylene blue (MB) dye degradation, which percentage degradation was 93% after 120 min. Also, the cytotoxicity of CaCO3-NPs has been examined on the normal L929 and cancer CT26 cell lines and the IC50 value was about 250 µg/mL for cancer cells. [ABSTRACT FROM AUTHOR]

[Display omitted] • Rosuvastatin, Ru, nanocrystals are co-precipitated on calcium carbonate, CC, nanoparticles. • Ru/CC nanoparticles enhance bone healing, improve bone microarchitecture, increase trabecular bone area, enhance osteogenic gene expression, and reduce osteoclast activity. • Ru/CC nanoparticles is a promising therapeutic approach for enhancing bone regeneration in osteoporosis. This study aimed at preparing sustained release rosuvastatin (Ru) calcium carbonate (CC) co-precipitate nano-formulation for local intra-osseous application in osteoporotic rats. Nano-formulations were prepared by the co-precipitation method using different concentrations of polyvinyl alcohol (PVA) (0.2, 0.4, 0.6 %) as a stabilizer and equimolar ratios of calcium chloride and calcium carbonate (0.1, 0.3 or 0.5 M). Pre-formulation examination including; FTIR and X-ray diffraction confirmed the formation of CC nanoparticles in a crystalline structure that was preserved before and after loading with Ru. The optimized formula showing; PS of 105.71 ± 5.10 nm, PDI of 0.25 ± 0.02, ZP of −44.70 ± 0.09 mV, % EE of 60.16 ± 1.58 and a quasi-spherical nanoparticle with nano-deposition of Ru crystals adsorbed on them as seen under TEM and SEM, was then integrated in 20 % Pluronic gel. The Ru-gel exhibited good rheological behavior with a short gelation time of 20 sec and a sustained release pattern of 30 % for the optimized Ru/CC gel versus ≈ 90 % for the Ru/CC dispersion after 6 h. In-vivo , ovariectomy-induced osteoporotic rats were used to cause a bone defect in the tibial metaphysis. The drill-hole defects were then filled with the formulations under test and examined 30 days postoperatively. Through SEM-EDX scanning, histological assessments, and evaluation of bone metabolic markers, Ru/CC treatment significantly enhanced bone healing, improved bone microarchitecture, increased trabecular bone area, enhanced osteogenic gene expression, and reduced osteoclast activity. Experiments proved that Ru/CC successfully enhances osteogenesis and reduces osteoclastogenesis, proposing it as a promising therapeutic approach for enhancing bone regeneration in osteoporosis. [ABSTRACT FROM AUTHOR]

The synthesis of high selectivity and permeance thin-film composite (TFC) membranes frequently encounters a significant challenge in balancing the permeance-selectivity trade-off. Recent research has demonstrated that the incorporating of nanomaterials into fabricated thin film nanocomposite (TFN) membranes is a feasible strategy to overcome this permeance-selectivity trade-off. Here we proposed using calcium carbonate nanoparticles (n-CaCO 3) as organic phase additives to modulate interfacial polymerization (IP) reaction to prepare TFN membrane. Molecular dynamics (MD) simulation was employed to explore the effects of n-CaCO 3 addition on the dispersion of organic phase monomers and on the diffusion of water phase monomers. The prepared TFN membrane (TFN-0.03) loaded with very little n-CaCO 3 (0.03 wt%) exhibited a high permeability of 16.9 ± 0.5 L m−2 h−1 bar−1, which was 1.7 times greater than that of the TFC membrane, and also maintained a high selectivity (Na 2 SO 4 rejection: 98.8 %). Our work furnishes the theoretical and experimental basis for the development of high performance TFN nanofiltration (NF) membranes. [Display omitted] • TFN membrane was prepared by adding nano-CaCO 3 in organic phase to modulate IP reaction. • Molecular dynamics simulation shows nano-CaCO 3 affecting the dispersion of TMC and the diffusion of PIP. • The obtained TFN membrane has a thinner, smoother, and looser PA layer. • The TFN membranes exhibits excellent separation performance and good stability. [ABSTRACT FROM AUTHOR]

Eggshell waste is considered the most abundant waste material from food processing technologies. Despite the freakish features that its components possess, it is very often discarded without further application. Nowadays, most researchers are focusing their research on pollution-free environment, biodegradable character, and balanced ecological aspects while fabricating the composite materials rather than mechanical strengths, costs, and processing methodologies. This study aimed to investigate the impact of the eggshell nanoparticles on the enhanced treatment of a bone fracture. The samples included 10 healthy female New Zealand white rabbits with an average body weight of 3 kg and age of 4 months years old. The animals were kept in an open place. All these ten rabbits had a fracture by making a surgical operation conducted by opening and excluding the muscle and anther tissue, followed by cutting the bone using a special small saw. After the operational step, the animals were divided into two groups (n=5). The fractures were checked by X-ray. The negative control group was left without treatment, however, was given 0.2 mL intraperitoneal saline injection weekly. The experimental group underwent treatment with 200 mg/kg of calcium carbonate nanoparticles (CaCO3-NPs) for 4 weeks. The animals were sacrificed at the end of the study period to collect organs for histological studies. Considering the results of the radiographic examination before and after treatment with CaCO3-NPs, the recorded data showed the speed of healing in the experimental group, compared to the control group. Regarding the histological study that was carried out on the vital organs, such as the liver, kidneys, heart, and lung, no side effects appeared when comparing the treatment group with the control group, except for some slight changes. In conclusion, the recorded data in the current study demonstrated that CaCO3-NPs had a beneficial effect on the pace of fracture recovery.

In this research, the effect of CaCO3 nanoparticles was experimentally investigated on vibrational damping behavior and static mechanical properties of polypropylene (PP). Hammer tests along with modal analysis were carried out to evaluate the forced vibration behavior of composite plates under one edge clamped support conditions while tensile tests were performed to assess the static mechanical properties. A comparison of the results showed an increment in the static mechanical properties of nanocomposites by increasing the nanoparticles content in the PP matrix. Composite with 10 wt.% nanoparticles showed the highest rise in Young’s modulus (39.71 %) compared to pure PP. An increment in Young’s modulus and stiffness led to an increasing trend in the damped natural frequencies of the nanocomposites so that the composite with 10 wt. % nanoparticles showed the highest damped natural frequency augmentation (23.6 %, 36.78 %, and 252.62 %) compared to pure PP in the first three modes. In addition, an enhancement in the nanoparticles content of the PP matrix led to an increasing trend in damping ratios of the nanocomposites such that the composite with 10 wt. % nanoparticles in the first mode (28.99 %) and composite with 7.5 wt. % nanoparticles in the second and third modes (418.66 % and 9.93 %) showed the highest rise in damping ratio compared to pure PP. Increasing damping ratios can be due to the proper dispersion of nanoparticles in the matrix and consequently energy dissipation of the stick-slip mechanism between the matrix and nanoparticles. Moreover, high nanoparticle contents had destructive effects on both the static and dynamic behavior of the composites.

Two field experiments were conducted at the Experimental Farm, Faculty of Agriculture, Fayoum University at "Dar-El- Ramed" Fayoum Governorate, Egypt during the two successive seasons of 2019 and 2020. The study was conducted in order to investigate the effect of withholding one irrigation at two stages as growth and three rates of Calcium carbonate nanoparticles as nano-fertilizers on growth parameters of some yellow single cross hybrids of maize under the environmental conditions of the experimentation area. The experimental layout was a split-split plot arranged in randomized complete block design with three replications where water stress treatments (skipping of some irrigations) were considered as the main plot, three yellow single cross hybrids of maize arranged in the sub-plot and the sub-sub plot occupied by three concentrations calcium carbonate nanoparticles treatments. Results indicated that irrigation treatment reflected positive significant influences on growth parameters, normal irrigation resulted in the best mean values of plant height, maximum number of leaves plant-1, largest leaf area plant-1 and heaviest dry weight plant-1 in both seasons 65 and 80 (DAS). Irrigation treatments had a significant effect on number of days from sowing to 50% tasseling in the two growing seasons. The maximum number of days from sowing to 50% tasseling due to irrigation were produced from the normal irrigation compared with the other irrigation treatments {(Withholding the 4th irrigation (65 DAP) and Withholding the 5th irrigation (80 DAP)}. While the minimum number of days from sowing to 50% tasseling were resulted from Withholding the 5th irrigation (80 DAP). Results showed that yellow single cross hybrids of maize were significantly differed in almost mean values of maize growth, under study in the both seasons. Maize hybrid of S. C. 2088 was significantly surpassed S. C. 2055 and S. C. 2066 in mean values of all growth characters. Calcium carbonate nanoparticles concentrations had a significant effect on growth parameters i. e. plant height, number of leaves/plant-1, dry weight plant-1, and total dry weight of plant in both seasons at 65 and 80 DAS. Application of high rate of calcium carbonate nanoparticles produced the highest values. [ABSTRACT FROM AUTHOR]

Calcium carbonate (CaCO3) particles represent an appealing choice as a drug delivery system due to their biocompatibility, biodegradability, simplicity and cost-effectiveness of manufacturing, and stimulus-responsiveness. Despite this, the synthesis of CaCO3 particles with controlled size in the nanometer range via a scalable manufacturing method remains a major challenge. Here, by using a co-precipitation technique, we investigated the impact on the particle size of different synthesis parameters, such as the salt concentration, reaction time, stirring speed, and temperature. Among them, the salt concentration and temperature resulted in having a remarkable effect on the particle size, enabling the preparation of well-dispersed spherical nanoparticles with a size below 200 nm. Upon identification of optimized synthesis conditions, the encapsulation of the antitumoral agent resveratrol into CaCO3 nanoparticles, without significantly impacting the overall size and morphology, has been successfully achieved. [ABSTRACT FROM AUTHOR]

In this study, the effect of the simultaneous incorporation of different contents of CaCO3 nanoparticles (NPs) and waste ground rubber tire powder (WGRT) on the forced vibration behavior of polypropylene (PP) was experimentally investigated. Hammer test with modal analysis was performed to investigate the vibrational behavior of the composite plates with one edge clamped (CFFF) support condition. Microstructural assessment of composites using Field Emission Scanning Electron Microscope (FESEM) images showed that a rise in CaCO3 nanoparticles in small weight percentages led to better dispersion and a decline in the tire phase size in the small weight percentage of WGRT. Moreover, a comparison of the modal analysis results revealed that all ternary composites, except in the first mode, had a higher damped natural frequency than pure PP. The damping ratio of all ternary composites, especially in the first and second modes, was higher than pure PP, which is due to the combined effect of WGRT and CaCO3 nanoparticles in increasing energy dissipation and damping of composites. [ABSTRACT FROM AUTHOR]

Eggshell waste is considered the most abundant waste material from food processing technologies. Despite the freakish features that its components possess, it is very often discarded without further application. Nowadays, most researchers are focusing their research on pollution-free environment, biodegradable character, and balanced ecological aspects while fabricating the composite materials rather than mechanical strengths, costs, and processing methodologies. This study aimed to investigate the impact of the eggshell nanoparticles on the enhanced treatment of a bone fracture. The samples included 10 healthy female New Zealand white rabbits with an average body weight of 3 kg and age of 4 months years old. The animals were kept in an open place. All these ten rabbits had a fracture by making a surgical operation conducted by opening and excluding the muscle and anther tissue, followed by cutting the bone using a special small saw. After the operational step, the animals were divided into two groups (n=5). The fractures were checked by X-ray. The negative control group was left without treatment, however, was given 0.2 mL intraperitoneal saline injection weekly. The experimental group underwent treatment with 200 mg/kg of calcium carbonate nanoparticles (CaCO3-NPs) for 4 weeks. The animals were sacrificed at the end of the study period to collect organs for histological studies. Considering the results of the radiographic examination before and after treatment with CaCO3-NPs, the recorded data showed the speed of healing in the experimental group, compared to the control group. Regarding the histological study that was carried out on the vital organs, such as the liver, kidneys, heart, and lung, no side effects appeared when comparing the treatment group with the control group, except for some slight changes. In conclusion, the recorded data in the current study demonstrated that CaCO3-NPs had a beneficial effect on the pace of fracture recovery. [ABSTRACT FROM AUTHOR]

To solve the problem of the reduction in strength due to the high-volume of fly ash (FA) in cement, this research investigates the influences of calcium carbonate nanoparticles (NCs) on the microstructure and strength of mortar containing 40% FA at the early and later ages. Two NCs (NC1 and NC2) were added at rates of 2% as a partial replacement for the binder, respectively. The characteristics of large capillary pores, the dense and porous areas, the constituent phase fractions, the hydration degree of the cement, the porosity, and the pore structure of mortar containing FA and NCs were analysed by backscattered electron imaging analysis (BSI). Mortar containing FA without NCs was used as a control mortar (PCFA). The results show that mortar containing 2% NCs exhibited about 13.6% and 6.7% higher compressive strengths than that of the PCFA at 3 and 180 days, respectively. Furthermore, the incorporation of the NCs decreases the porous hardened cement paste (HCP) areas, but increases the dense HCP. Besides, the results reveal that the hydration degree, the pore volume, and the larger capillary pores of the mortar containing the NCs is about 9.7%, 15.5%, and 30.5% lower than that of the PCFA at 3 days, respectively. The results of the BSI analysis also indicate that the NCs could reduce the porosity, the large capillary pores, and the porous HCP area of the mortar, creating a denser microstructure, resulting in a higher compressive strength in the later ages.

An optical biosensor for urea based on urease enzyme immobilised on functionalised calcium carbonate nanoparticles (CaCO3-NPs) was successfully developed in this study. CaCO3-NPs were synthesised from discarded cockle shells via a simple and eco-friendly approach, followed by surface functionalisation with succinimide ester groups. The fabricated biosensor is comprised of two layers. The first (bottom layer) contained functionalised NPs covalently immobilised to urease, and the second (uppermost layer) was alginate hydrogel physically immobilised to the pH indicator phenolphthalein. The biosensor provided a colorimetric indication of increasing urea concentrations by changing from colourless to pink. Quantitative urea analysis was performed by measuring the reflectance intensity of the colour change at a wavelength of 633.16 nm. The determination of urea concentration using this biosensor yielded a linear response range of 30–1000 mM (R2 = 0.9901) with a detection limit of 17.74 mM at pH 7.5. The relative standard deviation of reproducibility was 1.14%, with no signs of interference by major cations, such as K+, Na+, NH₄+, and Mg2+. The fabricated biosensor showed no significant difference with the standard method for the determination of urea in urine samples.

Strengthening tumor cellular adhesion through regulating the concentration of extracellular Ca 2+ is highly challenging and promising for antimetastasis. Herein, a pH-responsive conjugated polymer-calcium composite nanoparticle (PFV/CaCO 3 /PDA@PEG) is developed for calcium-mediated cell adhesion enhancement-based antimetastasis and reactive oxygen species (ROS)-triggered calcium overload and photodynamic therapy (PDT) synergistic tumor treatment. PFV/CaCO 3 /PDA@PEG is mainly equipped with conjugated poly(fluorene- co -vinylene) (PFV-COOH)-composited CaCO 3 nanoparticles, which can be rapidly decomposed under the tumor acidic microenvironment, effectively releasing Ca 2+ and the photosensitizer PFV-COOH. The high extracellular Ca 2+ concentration facilitates the generation of dimers between two adjacent cadherin ectodomains, which greatly enhances cell-cell adhesion and suppresses tumor metastasis. The inhibition rates are 97 and 87% for highly metastatic tumor cells 4T1 and MCF-7, respectively. Such a well-designed nanoparticle also contributes to realizing PDT, mitochondrial dysfunction, and ROS-triggered Ca 2+ overload synergistic therapy. Furthermore, PFV/CaCO 3 /PDA@PEG displayed superior in vivo inhibition of 4T1 tumor growth and demonstrated a marked antimetastatic effect by both intravenous and intratumoral injection modes. Thus, this study provides a powerful strategy for calcium-mediated metastasis inhibition for tumor therapy.

Laboratory-synthesized CaCO3 nanoparticles and their nanodispersion in 1,4-butanediol as a working medium have been first characterized and then tested on the surface of Pietraforte stone that forms the cladding of the bell tower of San Lorenzo. Both CaCO3 nanoparticles and their nanodispersion in 1,4-butanediol were characterized in the church in Florence, Italy by X-ray diffraction, thermal analysis, Raman, and Fourier transform infrared spectroscopy, scanning electron microscopy (SEM)/energy-dispersive X-ray (EDX) spectroscopy, and transmission electron microscopy/EDX spectroscopy. The Pietraforte sample surface, before and after CaCO3 nanodispersion treatments, was characterized by comparison of the porosity and specific surface area, capillary absorption, and surface hardness. An ultrastructural morphological investigation by SEM was also carried out, confirming and implementing the effective dynamics of the nanodispersion action. Lastly, differences in stone optical appearance before and after treatment were evaluated by colorimetric measurements. Considering the obtained results of the study, we conclude that CaCO3 nanodispersion in 1,4-butanediol is an effective restorative agent that prevents water infiltration in the stone, reduces stone disruption, and promotes its consolidation without altering its appearance. Finally, the long-lasting stability of the CaCO3 nanodispersion at ambient conditions makes it suitable for production and commercialization. [ABSTRACT FROM AUTHOR]

In the present study, we combined CaCO3 NPs and Ce6 to construct CaCO3-Ce6 nanoparticles (NPs). CaCO3-Ce6 NPs were characterized in terms of particle size, zeta potential, UV-Vis absorption spectrum, fluorescence spectrum, FTIR spectrum, and pH-responsive behavior. The reactive oxygen species (ROS) generation in vitro was measured in 4T1 cells. The results showed that CaCO3-Ce6 NPs were uniform-sized NPs with excellent fluorescence properties and pH-responsive behavior. The ability of ROS generation by CaCO3-Ce6 NPs was stronger compared with Ce6 in 4T1 cells because Ca2+ could enhance the ROS generation, which could contribute to a stronger anti-tumor effect. [ABSTRACT FROM AUTHOR]

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During summer seasons of 2015 and 2017, a field experiment was conducted at the Research and Experimental Station (30°19′ N, 31°16′ E), Faculty of Agriculture, Ain Shams University at Shalakan, Kalubia Governorate, Egypt, to investi-gate the effects of combinations between hydroxyl apatite nanoparticles (0, 3, and 6 kg/fad) and cal-cium carbonate nanoparticles (0, 500g/fad) as nano-fertilizers under irrigaton intervals, (irrigation every 2 or 3 weeks whereas irrigation every 2 weeks as a recommended practice) on growth of soybean plants. Irrigation intervals had statistically significant effect on plant height (cm), number of branches per plant, number of leaves per plant, leaf area index, number of pods per plant, number of root nodules per plant, root dry weight per plant, stem dry weight per plant, leaves dry weight per plant and pods dry weight per plant. These results were fairly true in the two studied seasons 2015, 2017 and combined result. plant height, numbers of branches per plant, numbers of leaves per plant, leaf area index, number of nodules per plant and number of pods per plant of soybean plants which treated with 500 g/fed surpassed untreated plants in the two studied seasons 2015, 2017 and com-bined. Soybean plants treated with 6 kg hydroxyl apatite nanoparticles per feddan out-numbered other plants in its numbers of leaves per plant, leaf area index, number of root nodules per plant and number of pods per plant in the two growing sea-sons 2015, 2017 and combined data. Results showed that normal irrigation x 500g/fed calcium carbonate nanoparticles x 6kg/fed hydroxyl apatite nanoparticles was the effective combination for producing the highest values of plant height (cm), number of branches per plant, number of leaves per plant, leaf area index, number of pods per plant, number of root nodules per plant, root dry weight per plant (g), stem dry weight per plant (g), leaves dry weight per plant (g) and pods dry weight per plant (g). There weren’t significant results be-tween plants treated with nano-mineral fertilizers under irrigation every 3 week and plants untreated but irrigated every 2 week in all growth traits, which reflect appositive result of this chemical substance in mitigation harmful effect of water shortage in season 2015, 2017 and combined data.

A series of calcium carbonate particles with sizes of 500 ± 80 and 200 ± 90 nm were obtained using mass crystallization in aqueous salt solutions by varying the reaction conditions and adding glycerol or a combination of polyethylene glycol, polysorbat-80 and cell cultural medium to the reaction volume. Calcium carbonate nanoparticles of 50 ± 30 nm in diameter were synthesized within the pores of mesoporous silica particles with a subsequent etching out of the template material. A complete characterization of the particles was carried out using scanning and transmission electron microscopy, X-ray powder diffraction, and dynamic and electrophoretic light scattering. CaCO3 particles were loaded with anticancer drugs, porphyrazine and doxorubicin, with an encapsulation efficiency of 2–5 and 4–11 wt.%, respectively. The spontaneous release at pH 7 reached 15%, and when the particles are dissolved at pH 4, the release was about 45% of the substance during the day, regardless of the encapsulated substance. Functionalization of the surface of calcium carbonate particles with a biocompatible Pluronic-folic acid conjugate did not affect the particle size distribution and aggregative stability for all three samples. The effect of coatings on the rate of internalization and accumulation of particles by cells expressing folic acid receptors was established. It was also shown that the internalization of 50 ± 30 nm particles was more active than other samples.

Every year a million tonnes of calcium rich agro and industrial waste are generated around the whole globe. These calcium rich waste like finger citron, shells of cockle, mussel, oysters etc., and egg shell are biological sources which have various organic compounds. The inorganic calcium rich waste includes gypsum, dolomite, sludge etc., which are produced in surplus amount globally. Most of these by-products are mainly dumped, while few are used for land-filling purposes which leads to the pollution. These agro and industrial by-products could be processed for the recovery of calcium carbonate and calcium oxide particles by physical and chemical method. The recovery of calcium carbonate and calcium oxide particles from such by products make them biocompatible. Moreover, the products are economical due to their synthesis from waste materials. Here, in this current review work we have emphasized on the all the calcium rich agro industries and industrial by products, especially their processing by various approaches. Further, we have also focused on the properties and application of such calcium carbonate and oxide particles for the remediation of organic and inorganic pollutants from the environments. The recovery of such particles from these byproducts is considered not only economical and eco-friendly but it also minimizes the pollution present in the form of solid waste. [ABSTRACT FROM AUTHOR]

Exploiting a comprehensive strategy that processes diagnosis and therapeutic functions is desired for eradicating tumors. In this study, two versatile nanoparticles are introduced: one is polyethylene glycol‐ and polyethyleneimine‐modified gold nanorods (mPEG–PEI–AuNRs), and the other is formed by electrostatic interactions between mPEG–PEI and calcium carbonate nanoparticles (mPEG–PEI/CaNPs). These two nanoparticles possess following favorable properties: 1) mPEG–PEI–AuNRs and mPEG–PEI/CaNPs show not only high cell uptake in acidic tumoral pH, but also efficient accumulation in tumors with prolonged circulation. 2) mPEG–PEI/CaNPs can generate carbon dioxide (CO2) bubbles in acidic tumoral environment and the photoacoustic (PA) signals from mPEG–PEI–AuNRs can be enhanced with the generation of CO2 bubbles. 3) The tumors can be eradicated by combining photothermal therapy (PTT) with ultrasonic therapy (UST) under the near‐infrared (NIR) laser and ultrasonic irradiation with the presence of mPEG–PEI–AuNRs and CO2 bubbles from mPEG–PEI/CaNPs. The detailed evaluation of cellular uptake, photothermal property of mPEG–PEI–AuNRs, CO2 bubbles' generation from mPEG–PEI/CaNPs, imaging, and combined PTT and UST are carried out in vitro or in vivo. This work has great potential usage for diagnosis and treatment in the future. [ABSTRACT FROM AUTHOR]

High-density polyethylene (HDPE) and nanoparticles of calcium carbonate (NCC) have been mixed via melt blending technique using different ratios of NCC as nanofiller and high-density polyethylene-g-maleic anhydride (HDPE-g-MA) as a compatibilizer. The combined effect of NCC as well as HDPE-g-MA concentrations on the breakdown strength and dielectric spectroscopy performance of HDPE was investigated. According to the American Society for Testing and Materials (ASTM) standard, the ac breakdown voltage of such nanocomposites was measured at constant 500 V/s ramp. The ac breakdown voltage was enhanced by 8.2% for HDPE/ 2wt% NCC and reached 21% in the presence of 1 wt% HDPE-g-MA which increases the efficiency of NCC dispersion. The surface morphology of synthesized HDPE/NCC and HDPE/NCC/HDPE-g-MA nanocomposites was characterized by field-emission scanning electron microscopy (FE-SEM). FE-SEM images showed an enhanced dispersion of NCC that may be due to good adhesion between NCC and HDPE under the compatibilization effect of HDPE-g-MA. Fourier-transform infrared (FTIR) analysis showed chemical interaction between HDPE-g-MA and stearic acid on the surface of NCC and physical entanglement among HDPE and HDPE-g-MA. Dielectric constant (ε′) and tangent loss (tan δ) were measured under different applied frequency values from 1 kHz to 1 MHz. [ABSTRACT FROM AUTHOR]

Engineered calcium carbonate (CaCO 3 ) particles are extensively used as drug delivery systems due to their availability, biological compatibility, biodegradability, and cost-effective production. The synthesis procedure of CaCO 3 particles, however, suffers from poor reproducibility. Furthermore, reducing the size of CaCO 3 particles to <100 nm requires the use of additives in the reaction, which increases the total reaction time. Here we propose on-chip synthesis and loading of nanoscaled CaCO 3 particles using microfluidics. After the development and fabrication of a microfluidic device, we optimized the synthesis of CaCO 3 NPs by varying different parameters such as flow rates in the microfluidic channels, concentration of reagents, and the reaction time. To prove the versatility of the used synthesis route, we performed single and double loading of CaCO 3 NPs with various compounds (Doxorubicin, Cy5 or FITC conjugated with BSA, and DNA) using the same microfluidic device. Further, the on-chip loaded CaCO 3 NPs were used as carriers to transfer compounds to model cells. We have developed a microfluidic synthesis method that opens up a new pathway for easy on-chip fabrication of functional nanoparticles for clinical use., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier B.V. All rights reserved.)

Heavy metals pollution in the environment is one of the serious problems in the field of water and wastewater management. In this study; calcium carbonate nanoparticles, synthesized by an efficient and novel method, were used as an adsorbent for the removal of lead and iron from aqueous solutions. To study the mechanism of adsorption, the kinetic and isotherm models were examined. The adsorption kinetics of process was found to follow a pseudo-second-order equation. The maximum monolayer adsorption capacities of calcium carbonate nanoparticles calculated from Langmuir isotherm were found to be 1210±30 mg/g for Pb(II) and 845±8 mg/g for Fe(II) ions, respectively. The response surface methodology based on three variable Box-Behnken design was utilized to evaluate the effects of temperature (25-65 oC) and initial metal concentration (10-200 mg/L) on the sorption process. The optimum conditions for the removal process using calcium carbonate nanoparticles were found to be 200 mg/L at 25 oC. Experimental data demonstrated that a precipitation transformation mechanism rather than adsorption enhances the removal efficiency.

Encapsulation or coating of nanoparticles constitutes a serious challenge in nanotechnology science and application by virtue of their very small sizes, high surface energy and high surface area. The present research is solely devoted to create innovative trends without such technology barrier for synthesis and characterization of different nanomaterials. The latter are exemplified by Zinc oxide nanoparticles (ZnO-NPs) and Titanium oxide nanoparticles (TiO2-NPs) using the sol gel method. Also included in these examples are calcium carbonate nanoparticles (CaCO3-NPs) which involve extra modification using stearic acid and; a new method whereby supercritical CO2 is used as an anti-solvent (SAS) for nanoparticle encapsulation. The as prepared PS nanocomposite acquires a surface area ranging from 54 to ≈ 168 m2/g with extension by 180%; in full agreement with the results of particle size. The as fabricated PS nanocomposites are advocated as effective candidates for use as active coating with small size and well-defined shape control along with excellent antimicrobial efficiency. In a more specific sense, this brilliant antimicrobial efficiency is reported against Staphylococcus aureus, Pseudomonas aeruginosa, yeast (Candidia albicans) and fungi (Aspergillus niger). This means that the current nanocomposite can be categorized under active packaging materials and, indeed, should be advocated for such domains. [ABSTRACT FROM AUTHOR]

Common procedures to incorporate the recycled crumb rubber (CR) in asphalt binders take a long time and use a high-temperature heating process, which makes these rubberized mixtures even more expensive and environment-unfriendly than conventional mixtures. In trying to make a cheaper and greener asphalt mixture, in this paper, the CR incorporation heating process and its duration were lowered (140–150°C in 15 minutes), and the effect of these changes was studied on the pavement's tensile/shear cracking resistance. Because the main disadvantage of using CR is the increase of viscosity, two by-products, slack wax (SW) and polypropylene wax (PPW) were used to correct the viscosity; also their effect on fracture toughness (K eff) and fracture energy (G f) was assessed. As results showed that the following process decreases the cracking resistance, calcium carbonate nanoparticles (CCN) in different contents were added. Results show that adding 15% CR reduces K eff and G f by about 18 and 16%, respectively. Adding the SW and PPW further reduces them by about 8 and 16%, respectively. In this condition, adding CCN in optimal content (about 5%) compensates for these reductions. Although these greener asphalts have the same cracking resistance as the control mixture, the environmental and cost-effectiveness analysis shows the developed materials are greener and cheaper. [Display omitted] • The effect of addition of crumb rubber to neat binder was studied. • The mechanical tests were done for the aim of cracking resistance measurement. • The calcium carbonate nanoparticles and two wax-based additives was used to enhance the performance. • Full range of mode I and II fracture was studied, experimentally and theoretically. • Statistical review, optimization and cost-environmental evaluation were done. [ABSTRACT FROM AUTHOR]

Abstract The evolution of nanomaterial in science has brought about a growing increase in nanotechnology, biomedicine, and engineering fields. This study was aimed at fabrication and characterization of conjugated gold-cockle shell-derived calcium carbonate nanoparticles (Au-CSCaCO3NPs) for biomedical application. The synthetic technique employed used gold nanoparticle citrate reduction method and a simple precipitation method coupled with mechanical use of a Programmable roller-ball mill. The synthesized conjugated nanomaterial was characterized for its physicochemical properties using transmission electron microscope (TEM), field emission scanning electron microscope (FESEM) equipped with energy dispersive X-ray (EDX) and Fourier transform infrared spectroscopy (FTIR). However, the intricacy of cellular mechanisms can prove challenging for nanomaterial like Au-CSCaCO3NPs and thus, the need for cytotoxicity assessment. The obtained spherical-shaped nanoparticles (light-green purplish) have an average diameter size of 35 ± 16 nm, high carbon and oxygen composition. The conjugated nanomaterial, also possesses a unique spectra for aragonite polymorph and carboxylic bond significantly supporting interactions between conjugated nanoparticles. The negative surface charge and spectra absorbance highlighted their stability. The resultant spherical shaped conjugated Au-CSCaCO3NPs could be a great nanomaterial for biomedical applications.