Calcium Carbonate Nanoparticles Research Articles

Acid-Triggered Release of Eugenol and Fluoride by Desensitizing Macro- and Nanoparticles

The modern dentifrice industry needs non-toxic materials able to adhere to dentin, occlude dentinal tubules, hold pharmacons at the surface of dentin, and release them on demand to the location the tooth needs them most. Novel dental materials loaded with eugenol or fluoride-ions examined for the release of the pharmacon in an aqueous suspension efficiently adhere to the surface of human dentin and occlude dentinal tubules as evidenced by Scanning Electron Microscopy (SEM). Ultraviolet-visible (UV-vis) absorption spectroscopy and a fluoride-selective electrode quantified the release of pharmacons. The surface modification with casein stabilizes micro- and nanoparticles of calcium carbonate in aqueous suspensions, enabling their application in dentifrices. The ability of particles to hold and release eugenol depends on their morphology and composition, with the casein-coated calcium carbonate microspheres being the most acid-sensitive and most promising for dentifrice applications. The novel material releases fluoride under physiologically low pH, regardless of the presence of other ingredients of the artificial saliva, which sustains the bulk fluoride concentration comparable with most fluorinated toothpastes. Low pH-triggered release mechanisms selectively supply the drug to the areas that need it most, reducing the overall dose and ushering in a new type of targeted dentifrices.

Bioprocess inspired formation of calcite mesocrystals by cation-mediated particle attachment mechanism.

Calcite mesocrystals were proposed, and have been widely reported, to form in the presence of polymer additives via oriented assembly of nanoparticles. However, the formation mechanism and the role of polymer additives remain elusive. Here, inspired by the biomineralization process of sea urchin spine comprising magnesium calcite mesocrystals, we show that calcite mesocrystals could also be obtained via attachment of amorphous calcium carbonate (ACC) nanoparticles in the presence of inorganic zinc ions. Moreover, we demonstrate that zinc ions can induce the formation of temporarily stabilized amorphous nanoparticles of less than 20nm at a significantly lower calcium carbonate concentration as compared to pure solution, which is energetically beneficial for the attachment and occlusion during calcite growth. The cation-mediated particle attachment crystallization significantly improves our understanding of mesocrystal formation mechanisms in biomineralization and offers new opportunities to bioprocess inspired inorganic ions regulated materials fabrication.

Monodisperse CaCO3-loaded gelatin microspheres for reversing lactic acid-induced chemotherapy resistance during TACE treatment

Transarterial chemoembolization (TACE) is an important approach for the treatment of unresectable hepatocellular carcinoma (HCC). However, the lactic acid-induced acidic tumor microenvironment (TME) may reduce the therapeutic outcome of TACE. Herein, monodispersed gelatin microspheres loaded with calcium carbonate nanoparticles (CaNPs@Gel-MS) as novel embolic agents were prepared by a simplified microfluidic device. It was found that the particle size and homogeneity of as-prepared CaNPs@Gel-MS were strongly dependent on the flow rates of continuous and dispersed phases, and the inner diameter of syringe needle. The introduction of CaNPs provided the gelatin microspheres with an enhanced ability to encapsulate the chemotherapeutic drug of DOX, as well as a pH-responsive sustained drug release behavior. In vitro results revealed that CaNPs@Gel-MS could largely increase the cellular uptake and chemotoxicity of DOX by neutralizing the lactic acid in the culture medium. In addition, CaNPs@Gel-MS exhibited an excellent and persistent embolic efficiency in a rabbit renal model. Finally, we found that TACE treatment with DOX-loaded CaNPs@Gel-MS (DOX/CaNPs@Gel-MS) had a much stronger ability to inhibit tumor growth than the DOX-loaded gelatin microspheres without CaNPs (DOX@Gel-MS). Overall, CaNPs@Gel-MS could be a promising embolic microsphere that can significantly improve anti-HCC ability by reversing lactic acid-induced chemotherapy resistance during TACE treatment.

Multifunctional Nanoparticles Codelivering Doxorubicin and Amorphous Calcium Carbonate Preloaded with Indocyanine Green for Enhanced Chemo-Photothermal Cancer Therapy.

Multifunctional stimuli-responsive nanoparticles with photothermal-chemotherapy provided a powerful tool for improving the accuracy and efficiency in the treatment of malignant tumors. Herein, photosensitizer indocyanine green (ICG)-loaded amorphous calcium-carbonate (ICG@) nanoparticle was prepared by a gas diffusion reaction. Doxorubicin (DOX) and ICG@ were simultaneously encapsulated into poly(lactic-co-glycolic acid)-ss-chondroitin sulfate A (PSC) nanoparticles by a film hydration method. The obtained PSC/ICG@+DOX hybrid nanoparticles were characterized and evaluated by Fourier transform infrared spectroscopy (FTIR), dynamic light scattering (DLS), transmission electron microscopy (TEM), and differential scanning calorimetry (DSC). The cellular uptake and cytotoxicity of PSC/ICG@+DOX nanoparticles were analyzed by confocal laser scanning microscopy (CLSM) and MTT assay in 4T1 cells. In vivo antitumor activity of the nanoparticles was evaluated in 4T1-bearing Balb/c mice. PSC/ICG@+DOX nanoparticles were nearly spherical in shape by TEM observation, and the diameter was 407 nm determined by DLS. Owing to calcium carbonate and disulfide bond linked copolymer, PSC/ICG@+DOX nanoparticles exhibited pH and reduction-sensitive drug release. Further, PSC/ICG@+DOX nanoparticles showed an effective photothermal effect under near-infrared (NIR) laser irradiation, and improved cellular uptake and cytotoxicity in breast cancer 4T1 cells. Importantly, PSC/ICG@+DOX nanoparticles demonstrated the most effective suppression of tumor growth in orthotopic 4T1-bearing mice among the treatment groups. In contrast with single chemotherapy or photothermal therapy, chemo-photothermal treatment by PSC/ICG@+DOX nanoparticles synergistically inhibited the growth of 4T1 cells. This study demonstrated that PSC/ICG@+DOX nanoparticles with active targeting and stimuli-sensitivity would be a promising strategy to enhance chemo-photothermal cancer therapy.

Effect of calcium carbonate nanoparticles on mechanical properties of coir-kenaf based epoxy hybrid composites: An analytical and simulation study

The manufacturing sector is presently in search of sustainable materials that are lighter in weight, readily available, biodegradable, and cost-friendly. Natural fibers are observed to bring unblemished advancement in composite materials. In this research, a novel hybrid composite material has been analyzed. The composite comprises two different natural fibers, kenaf and coir fiber, reinforced in epoxy matrix with nanofillers of calcium carbonate particles. The weight percent of kenaf and coir fibers is maintained at 5.7% and 10%, whereas nanofillers is varied as 0%, 2%, and 4%, respectively, in all three samples. The elastic characteristics like the Longitudinal Modulus, and Transverse Modulus, are evaluated for the proposed composite utilizing five different analytical models, and are also interpreted using Representative Volume Element (RVE) analysis. The analytical results of the proposed composite are correlated with the experimental work in the earlier research. The influence of nanofiller is investigated and it has been observed that the composite with a higher filler content of 4 percent attains enhanced strength than a sample with a lower filler content of 0 and 2 wt. percent. The transverse modulus is noticed to uplift by 16.88%, and the longitudinal modulus by 11.14% on the mixing of CaCO3 particles in coir kenaf composite. Also, the composite is analyzed for hybridization effect, which proves to be one of the most promising ways to improve the features of the hybrid composite

Effect of calcium carbonate nanoparticles on mechanical properties of coir-kenaf based epoxy hybrid composites: An analytical and simulation study

The manufacturing sector is presently in search of sustainable materials that are lighter in weight, readily available, biodegradable, and cost-friendly. Natural fibers are observed to bring unblemished advancement in composite materials. In this research, a novel hybrid composite material has been analyzed. The composite comprises two different natural fibers, kenaf and coir fiber, reinforced in epoxy matrix with nanofillers of calcium carbonate particles. The weight percent of kenaf and coir fibers is maintained at 5.7% and 10%, whereas nanofillers is varied as 0%, 2%, and 4%, respectively, in all three samples. The elastic characteristics like the Longitudinal Modulus, and Transverse Modulus, are evaluated for the proposed composite utilizing five different analytical models, and are also interpreted using Representative Volume Element (RVE) analysis. The analytical results of the proposed composite are correlated with the experimental work in the earlier research. The influence of nanofiller is investigated and it has been observed that the composite with a higher filler content of 4 percent attains enhanced strength than a sample with a lower filler content of 0 and 2 wt. percent. The transverse modulus is noticed to uplift by 16.88%, and the longitudinal modulus by 11.14% on the mixing of CaCO3 particles in coir kenaf composite. Also, the composite is analyzed for hybridization effect, which proves to be one of the most promising ways to improve the features of the hybrid composite.

Computer quantum-chemical simulation of the interaction of calcium carbonate with biopolymers

As part of this work, computer quantum chemical modeling of the interaction of calcium carbonate with biopolymers (chitosan, hydroxyethylcellulose, hyaluronic acid) was carried out. Quantum chemical modeling was carried out using QChem software and the IQmol molecular editor. At the first stage, modeling of the calcium carbonate molecule and molecules of chitosan, methylcellulose, hydroxyethylcellulose, hyaluronic acid was carried out, then the molecular complex ―calcium carbonate - biopolymer‖ was considered, in which the interaction of calcium carbonate with biopolymers was considered as the interaction of the calcium atom in calcium carbonate with the functional groups of biopolymers. As a result, models of molecular complexes were obtained, and the values of the total energy of the molecular complex, the energy of the highest occupied and lowest free molecular orbitals, chemical hardness and the difference in the total energy of the amino acid and the molecular complex ―calcium carbonate - biopolymer‖ were calculated. As a result, it was found that chitosan, hydroxyethylcellulose, and hyaluronic acid can be used to stabilize calcium carbonate nanoparticles, which is confirmed by the values of the difference in total energy and chemical rigidity of molecular complexes. It has been shown that for chitosan the optimal interaction (∆E = 939.445 kcal/mol, ε = 0.026 eV) is the connection through the amino group attached to the C2 glucosamine residue, for hydroxyethylcellulose - the connection through the hydroxyl group attached to the C6 ethoxy group (∆E = 939.762 kcal/mol, ε = 0.036 eV), for hyaluronic acid – connection through the hydroxyl group attached to the C6 residue of N-acetylglucosamine (∆E = 939.413 kcal/mol, ε = 0.022 eV).

Novel PVDF-PEG-CaCO3 Membranes to Achieve the Objectives of the Water Circular Economy by Removing Pharmaceuticals from the Aquatic Environment.

In the aquatic environment, substances of pharmacological origin are common contaminants. The difficulty of removing them from water is a problem for the implementation of a circular economy policy. When recycling water, an effort should be made to remove, or at least, minimize the presence of these substances in the water. Porous membranes with a new functionality consisting in their adsorption capacity towards pharmaceutical substances have been developed. A Polyvinylidene Fluoride (PVDF) membrane with Calcium Carbonate (CaCO3) nanoparticles as an adsorbent was prepared. By implementing an integrated filtration-adsorption process using sulphadiazine, as a representative of pharmacological substances, 57 mg/m2 of adsorption capacity has been obtained, which is an improvement in adsorption properties of more than 50 times that of a commercial membrane. At the same time the membrane permeability is 0.29 m3/(h·m2·bar), which means that the membrane's permeability was improved by 75%.

Preparation and properties of environmentally benign waterborne polyurethane composites from sodium-alginate-modified nano calcium carbonate

Well-dispersed inorganic nanoparticles in organic polymers are critical in the preparation of high-performance nanocomposites. This study prepared a series of waterborne polyurethane (WPU)/calcium carbonate nanocomposites using the solution blending method. Next, FT-IR, TG-DTG and XRD tests were carried out to confirm that the biopolymer sodium alginate (SA) was successfully encapsulated on the surface of the calcium carbonate nanoparticles, and that SA achieved satisfactory surface modification of the calcium carbonate nanoparticles. The Zeta and ultraviolet (UV) absorbance test results reveal that SA-modified nano calcium carbonate (MCC) had good dispersion stability in water. The effects of the MCC dosage on the composite mechanical properties, thermal stability, and cross-sectional morphology observed by scanning electron microscopy, and the water resistance of the nanocomposite were investigated. The results reveal that the incorporation of 3wt% of MCC in WPU had stable distribution, which led to a 54% increase in the tensile strength of the nanocomposite, while maintaining excellent elongation at break (2187%) and increasing the maximum decomposition temperature to 419.6 °C. Importantly, the improved water resistance facilitates the application of this environmentally benign composite material in humid environments.

Biomimetic calcium carbonate nanoparticles delivered IL-12 mRNA for targeted glioblastoma sono-immunotherapy by ultrasound-induced necroptosis.

Glioblastoma (GBM) is the most aggressive brain tumor, which owns the characteristics of high recurrence, low survival rate and poor prognosis because of the existence of blood brain barrier (BBB) and complicated brain tumor microenvironment. Currently, immunotherapy has attracted much attention on account of favorable therapeutic effect. In this study, we designed a cRGD-modified cancer cell membrane (CM) coated calcium carbonate nanoparticle to deliver interleukin-12 messenger RNA (IL-12 mRNA@cRGD-CM-CaCO3 NPs). The cRGD-modified CM as the shell can endow the nanoparticles with BBB crossing and tumor homing/homotypic targeting effect in the brain tumor microenvironment. IL-12 mRNA-loaded calcium carbonate nanoparticles as the core allow synergistic immunotherapy of necroptosis-induced immune response and IL-12 mRNA transfection under ultrasound irradiation. The as-prepared biomimetic nanoparticles showed superior target and immunotherapeutic outcomes, suggesting that this biomimetic nanoplatform provides a feasible strategy for promoting BBB-penetrating and antitumor immunity.

Synthesis of stable calcium carbonate nanoparticles for pH-responsive controlled drug release

The construction of controlled release for drugs is a promising strategy in disease treatment, which can improve the bioavailability of utilized drugs and reduce the side effects. Herein, a simple and green strategy was developed to prepare stable amorphous calcium carbonate (ACC) using polyvinyl pyrrolidone (PVP) as stabilizer. The crystallization behavior of ACC nanoparticles in methanol–water system and the effect of PVP content on ACC was investigated. Most importantly, the obtained ACC-PVP exhibited high drug loading efficiency and pH responsive release properties for anticancer drugs 5-Fluorouracil (5-FU) and curcumin (CUR) in phosphate buffer solution and simulated gastric juice. All evidences demonstrate that smart mesoporous ACC-PVP nanoparticles provide a potential clinical application platform for cancer therapy.

Monitoring interactions through molecular dynamics simulations: effect of calcium carbonate on the mechanical properties of cellulose composites

This study describes the preparation and characterization of full atomistic models of amorphous cellulose and calcium carbonate (CaCO3) nanocomposite to assess its mechanical properties within and beyond the elastic limit via molecular dynamics simulations. The interactions by hydrogen bond and conformation of the cellulose molecules from the assessment of torsional angles were specifically monitored during the tensile stretching simulations to get deep understanding of the possible structural changes produced in the material during the deformation. On the one hand, the results showed a favorable interaction of the cellulose matrix with the calcium carbonate nanoparticle, with the electrostatic contribution being dominant over the van der Waals component. The determined mechanical elastic constants indicated that the inclusion of the CaCO3 nanoparticle provided an increase on the rigidity of the composite system of 15%, 18% and 19% in the Young, shear or bulk modulus, respectively. On the other hand, using extension and compression simulations, the recovery capacity of the material systems was also assessed in terms of plastic deformation. The elastoplastic behavior was observed for either the neat or the CaCO3 nanocomposite, with an elastic limit around 2.5%. The results also showed that the presence of the CaCO3 nanoparticle produced higher values of plastic deformation in the composite material compared to the neat cellulose system and thus decreased the flexibility of the material. A hysteresis mechanism was identified together with irreversible conformational changes on the cellulose molecules which would explain the plastic deformation observed on the cellulosic systems. It was concluded that the higher plastic deformations observed in the nanocomposite system would be a result of the disruption of the network of hydrogen bonds and the associated decrease on the number of possible interactions.Graphical

Preparation of Bio-Based Aerogel and Its Adsorption Properties for Organic Dyes.

The effective utilization of biomass and the purification of dye wastewater are urgent problems. In this study, a biomass aerogel (CaCO3@starch/polyacrylamide/TEMPO-oxidized nanocellulose, CaCO3@STA/PAM/TOCN) was prepared by combining nanocellulose with starch and introducing calcium carbonate nanoparticles, which exhibited a rich three-dimensional layered porous structure with a very light mass. Starch and nanocellulose can be grafted onto the molecular chain of acrylamide, while calcium carbonate nanopores can make the gel pore size uniform and have excellent swelling properties. Here, various factors affecting the adsorption behavior of this aerogel, such as pH, contact time, ambient temperature, and initial concentration, are investigated. From the kinetic data, it can be obtained that the adsorption process fits well with the pseudo-second-order. The Langmuir isotherm model can fit the equilibrium data well. The thermodynamic data also demonstrated the spontaneous and heat-absorbing properties of anionic and cationic dyes on CaCO3@STA/PAM/TOCN aerogels. The adsorption capacity of Congo red (CR) and methylene blue (MB) by CaCO3@STA/PAM/TOCN was 277.76 mg/g and 101.01 mg/g, respectively. Therefore, cellulose and starch-based aerogels can be considered promising adsorbents for the treatment of dye wastewater.

Strontium Carbonate and Strontium-Substituted Calcium Carbonate Nanoparticles Form Protective Deposits on Dentin Surface and Enhance Human Dental Pulp Stem Cells Mineralization.

Strontium acetate is applied for dental hypersensitivity treatment; however, the use of strontium carbonates for this purpose has not been described. The use of Sr-carbonate nanoparticles takes advantage of both the benefits of strontium on dentin mineralization and the abrasive properties of carbonates. Here in, we aimed to synthesize strontium carbonate and strontium-substituted calcium carbonate nanoparticles and test them as potential compounds in active dentifrices for treating dental hypersensitivity. For this, SrCO3, Sr0.5Ca0.5CO3, and CaCO3 nanoparticles were precipitated using Na2CO3, SrCl2, and/or CaCl2 as precursors. Their morphology and crystallinity were evaluated by electron microscopy (SEM) and X-ray diffraction, respectively. The nanoparticles were added to a poly (vinyl alcohol) gel and used to brush dentin surfaces isolated from human third molars. Dentin chemical composition before and after brushing was investigated by infrared spectroscopy (FTIR) and X-ray dispersive energy spectroscopy. Dentin tubule morphology, obliteration, and resistance of the coatings to acid attack were investigated by SEM and EDS. The cytotoxicity and ability of the particles to trigger the mineralization of hDPSCs in vitro were studied. Dentin brushed with the nanoparticles was coated by a mineral layer that was also able to penetrate the tubules, while CaCO3 remained as individual particles on the surface. FTIR bands related to carbonate groups were intensified after brushing with either SrCO3 or Sr0.5Ca0.5CO3. The shift of the phosphate-related FTIR band to a lower wavenumber indicated that strontium replaced calcium on the dentin structure after treatment. The coating promoted by SrCO3 or Sr0.5Ca0.5CO3 resisted the acid attack, while calcium and phosphorus were removed from the top of the dentin surface. The nanoparticles were not toxic to hDPSCs and elicited mineralization of the cells, as revealed by increased mineral nodule formation and enhanced expression of COL1, ALP, and RUNX2. Adding Sr0.5Ca0.5CO3 as an active ingredient in dentifrices formulations may be commercially advantageous since this compound combines the well-known abrasive properties of calcium carbonate with the mineralization ability of strontium, while the final cost remains between the cost of CaCO3 and SrCO3. The novel Sr0.5Ca0.5CO3 nanoparticles might emerge as an alternative for the treatment of dental hypersensitivity.

Recent Advances of Calcium Carbonate Nanoparticles for Biomedical Applications.

Calcium carbonate nanoparticles have been widely used in biomedicine due to their biocompatibility and biodegradability. Recently, calcium carbonate nanoparticles are largely integrated with imaging contrast and therapeutic agents for various imaging and therapeutic approaches. In this review, we first described the advantages and preparation methods of calcium carbonate nanoparticles, then the state-of-the-art progress of calcium carbonate nanoparticles in diagnosis, treatment and theranostics was summarized. Finally, we discussed the challenges and recommendations for future studies of the calcium carbonate nanoparticles.

Colon cancer exosome-derived biomimetic nanoplatform for curcumin-mediated sonodynamic therapy and calcium overload

Sonodynamic therapy (SDT) possesses unique properties such as being minimally invasive, exhibiting low toxicity, as well as ability to impart the treatment in the deep tissues, and hence has been extensively used. However, inherent defects such as low water-soluble sonosensitizers can limit the clinical application of SDT, and tumor microenvironment (TME) can further compromise the effect of a single SDT. To overcome these challenges, we have designed a bionic nano-system (ECaC) by coating mesoporous calcium carbonate nanoparticles (CaCO3 NPs) and sonosensitizer curcumin (Cur) into tumor-derived exosomes for developing enhanced SDT. Exosome membrane could endow CaCO3 NPs with homologous targeting abilities. In addition, compared with the bare CaCO3 NPs, ECaC showed significant accumulation in the tumor cell species. Subsequently, CaCO3 NPs upon reaching the tumor site can be degraded into Ca2+ in response to the acidic microenvironment of the tumor to destroy the cellular mitochondria. Hence, the cellular respiration could be destroyed to be a vulnerable state, causing oxidative stress, enhancing Cur-mediated chemotherapy/SDT. This synergistically dynamic therapy has demonstrated significant anti-tumor effects under in vitro and in vivo settings without exhibiting any toxic side effects. Our prepared biomimetic nano-system can effectively deliver the hydrophobic Cur to the tumor sites, which holds great promise in field of drug delivery and can broaden the application of exosomes, as this method has a certain enlightenment effect on the subsequent development of exosomes.

Curcumin-loaded cockle shell-derived calcium carbonate nanoparticles ameliorates lead-induced neurotoxicity in rats via attenuation of oxidative stress.

A substantial global health burden is associated with neurotoxicity caused by lead (Pb) exposure and the common mechanism of this toxicity is mainly via oxidative damage. Curcumin has remarkable pharmacological activities but remains clinically constrained due to its poor bioavailability when orally administered. Currently, cockle shell-derived calcium carbonate nanoparticle (CSCaCO3NP) is gaining more acceptance in nanomedicine as a nanocarrier to various therapeutics. This study aimed at investigating the ameliorative effect of curcumin-loaded CSCaCO3NP (Cur-CSCaCO3NP) on lead-induced neurotoxicity in rats. A total of 36 male Sprague-Dawley rats were randomly assigned into five groups. Each group consists of 6 rats apart from the control group which consists of 12 rats. During the 4 weeks induction phase, all rats received a flat dose of 50 mg/kg of lead while the control group received normal saline. The treatment phase lasted for 4 weeks, and all rats received various doses of treatments as follows: group C (Cur 100) received 100 mg/kg of curcumin, group D (Cur-CSCaCO3NP 50) received 50 mg/kg of Cur-CSCaCO3NP, and group E (Cur-CSCaCO3NP 100) received 100 mg/kg of Cur-CSCaCO3NP. The motor function test was carried out using the horizontal bar method. The cerebral and cerebellar oxidative biomarker levels were estimated using ELISA and enzyme assay kits. Lead-administered rats revealed a significant decrease in motor scores and SOD activities with a resultant increase in MDA levels. Furthermore, marked cellular death of the cerebral and cerebellar cortex was observed. Conversely, treatment with Cur-CSCaCO3NP demonstrated enhanced ameliorative effects when compared with free curcumin treatment by significantly reversing the aforementioned alterations caused by lead. Thus, CSCaCO3NP enhanced the efficacy of curcumin by ameliorating the lead-induced neurotoxicity via enhanced attenuation of oxidative stress.

Crystallization pathways, fabrics and the capture of climate proxies in speleothems: Examples from the tropics

The quality of climate proxy data from speleothem archives depends to varying degrees on crystallization processes, which result in diverse fabrics. Here, we document shifts in calcite growth mechanisms, from ion-by-ion to nanoparticle/nanocrystal attachment, in stalagmites from the tropical island of Atiu (South Pacific). Changes in solution stoichiometry and organic matter content result in the development of two columnar fabrics that are common elsewhere in settings characterized by seasonal contrast. A porous columnar fabric, characterized by intracrystalline micro and nanoporosity grows via a non-classical pathway through amorphous calcium carbonate (ACC) nanoparticles (∼2–4 nm in diameter) and calcite nanocrystal attachment. Despite subsequent transformation of nanoparticles/crystals into a large calcite crystal, the porous columnar fabric appears to preserve a δ18O signal that faithfully reflects that of the parent fluid via quasi-equilibrium fractionation. Furthermore, the porous fabric shows random and fuzzy lateral distributions of Sr, another hydrological proxy, yet this element's incorporation follows equilibrium partitioning. The chemical properties of compact columnar fabrics, which appear to grow by classical ion-by-ion attachment, may not directly reflect those of the original depositional environment because of degassing, the presence of growth inhibitors (such as Na) and very early diagenetic modifications. Columnar porous calcite fabrics that formed through non-classical pathways in other settings may faithfully record the original properties of the parent drip water, whereas compact fabrics that formed through classical pathways elsewhere may not. It is concluded that the study of fabrics at the nano-scale is a necessary complement to speleothem research to identify the influence of crystallization pathways on the accuracy of proxy data.

Edible starch films enhanced using CaCO3 nanoparticles and plasticizers by optimized extrusion-casting process

Edible films (EF) can be produced and developed for preservation of fruits and vegetables. Starch has been considered one of the biopolymers with the greatest potential to produce edible films by different processing techniques such as extrusion-casting. The objetive was to study the effect of calcium carbonate nanoparticles and plasticizers (sorbitol- glycerol (80-20%; w/w)) (by extrusion (EXT)-casting (CT) combination technologies to obtain EF with improved mechanical and barrier properties. Corn starch-plasticizers were processed in a twin screw extruder to produce thermoplastic starch modified followed by the addition of the calcium carbonate nanoparticles (CCNP) in casting to EF formation. A hybrid design (four factors; twenty one treatments) of surface response methodology was used to optimization process. The optimal EF was characterized mechanical and barrier properties and also characterized according to microstructural properties (X-ray diffraction, Scanning Electron Microscopy) to determine the damage caused in the starch during EXT and CT. In conclusion, it is possible to obtain EF with greater both Breaking Strength and Deformation, as well as, lower Water Vapor Permeability and Solubility (mechanical and barrier properties), through the use of CCNP and plasticizers, using EXT-CT combination processes.

A multifunctional nanoparticle for efferocytosis and pro-resolving-mediated endometriosis therapy

Endometriosis is an inflammation-dependent disorder characterized by the abnormal growth of endometrium-like lesions. In recent years, there is a great deal of interest in the development of anti-inflammatory therapy. Herein, an acid-sensitive calcium carbonate nanoparticle (CaNP) incorporated BML-111 (BML@CaNP) was prepared. BML@CaNP acted as a Ca2+ nanomodulator for efferocytosis (macrophages engulf apoptotic cells). Specifically, BML@CaNP induced the apoptosis of endometriotic stromal cells and enhanced the efferocytosis of macrophages. In addition, the particle can also deliver BML to the ectopic lesion for resolving the inflammatory response. In vivo BML@CaNP effectively suppressed lesion growth in endometriosis mice model, which could be attributed to the enhancing efferocytosis of cells and the lower levels of inflammatory factors in peritoneal fluid. In addition, these nanoparticles did not show side effects. In all, we provide a new anti-inflammatory strategy by both enhancing efferocytosis and resolving inflammation for the treatment of endometriosis.