Calcium Carbonate Research Articles

Effects of thunder-fire moxibustion on balance function and musculoskeletal metabolism in female patients of primary osteoporosis with low muscle mass

To observe the effects of thunder-fire moxibustion on the balance function and musculoskeletal metabolism in female patients of primary osteoporosis (POP) with low muscle mass. Sixty female patients of POP with low muscle mass were randomly divided into an observation group (30 cases, 5 cases dropped out) and a control group (30 cases, 2 cases dropped out). The patients in the control group were treated with oral administration of Caltrate D (1.5 g calcium carbonate + 125 IU vitamin D3), one tablet per day for 12 weeks. In addition to the control treatment, the patients in the observation group were treated with thunder-fire moxibustion at Mingmen (GV 4), Yaoyangguan (GV 3), bilateral Ganshu (BL 18), Shenshu (BL 23), and Dachangshu (BL 25), 30 min per acupoint, once every other day, three times a week, for 12 weeks. Balance function indexes (95% confidence ellipse area of the center of pressure [COP], total displacement, average speed), lumbar pain visual analogue scale (VAS), serum muscle metabolism factors (myostatin [MSTN], peroxisome proliferator-activated receptor γ coactivator-1α [PGC-1α]) and bone metabolism factors (aminoterminal propeptide typeⅠ procollagen [PINP], C-terminal telopeptide of typeⅠcollagen [CTX-Ⅰ]) were compared before and after treatment in both groups. Compared before treatment, the 95% confidence ellipse area of COP, total displacement, and average speed in the observation group were decreased after treatment (P<0.01), and the above indexes in the observation group were lower than those in the control group (P<0.05). Compared before treatment, the VAS scores in both groups were decreased after treatment (P<0.01), the score in the observation group was lower than that in the control group (P<0.01). Compared before treatment, the serum levels of MSTN, PINP and CTX-Ⅰ in the observation group were reduced after treatment (P<0.01), while the serum level of PGC-1α was increased (P<0.01). The control group showed a decrease in serum level of MSTN (P<0.05). The observation group had lower serum levels of MSTN and PINP (P<0.05) and higher serum level of PGC-1α (P<0.01) compared to the control group. The thunder-fire moxibustion can effectively relieve lumbar pain, improve balance function, and regulate musculoskeletal metabolism in female patients of POP with low muscle mass.

Unveiling the carbonation behavior of T-C3S and M-C3S: A comparative investigation

Numerous studies have investigated the carbonation process of tricalcium silicate (C3S). However, research on the carbonation of its different crystal forms remains relatively limited. This study explored the effects of accelerated carbonation on the performance and microstructure of T-C3S and M-C3S. The findings indicated that both T-C3S and M-C3S exhibited a rapid carbonation reaction rate during the initial 12 h, which subsequently declined gradually. The carbonation products of T-C3S and M-C3S primarily consisted of calcite, with T-C3S also containing a proportion of aragonite calcium carbonate. The decomposition peak temperature of calcium carbonate weight loss increased with prolonged carbonation time for both C3S crystal forms. Prismatic or cubic morphology calcite formed in T-C3S and M-C3S during the initial carbonation stages, leading to a denser microstructure. As the carbonation duration increased, the particle size of calcite also grew, displaying a more irregular morphology. Furthermore, needle-like or rod-like aragonite calcium carbonate was observed in T-C3S. T-C3S exhibited superior compressive strength compared to M-C3S at all stages of carbonation. Additionally, a relationship was established between compressive strength, calcium carbonate content, and CO2 uptake. This study provided evidence that the crystal structure of C3S not only influenced the rate of the carbonation reaction but also impacted the type and morphology of calcium carbonate products and the development of compressive strength.

Crack-healing and rheological properties of high content fly ash/slag/silica fume green and sustainable cement-based materials incorporating crystalline admixture and calcium alginate biomass hydrogel

Cracking is an important factor affecting the durability of concrete. Rheological properties are important performance indicators of the workability of fresh concrete. Ion chelator (CA) is one kind of crystalline admixture, which can enhance crack-healing of concrete by promoting the formation of calcium carbonate in wet environment. Calcium alginate hydrogel (CaAlg) can maintain the humidity of cementitious matrix and promote the crystallization of inorganic minerals. Therefore, in this study, CaAlg bead was prepared to further improve the crack-healing of cementitious materials containing CA. Self-healing performance was evaluated by visual crack closure and water permeability test. Rheological property was measured by rotor rheometer. Healing mechanism of cementitious materials with CA and CaAlg was analyzed. Results showed that with the increase of CaAlg dosage, yield stress and plastic viscosity of paste decreased gradually. Meanwhile, fly ash and slag reduced viscosity of pastes, while silica fume increased the viscosity of pastes. CA could evidently improve the permeability and mechanical properties of mortar, especially for slag mortar. Self-healing performance test and characterization showed that CaAlg could further enhance crack-healing process of mortar with CA, especially for pure cement and slag mortar. Microscopic testing indicates that CaAlg could induce the formation of vaterite and calcite on its surface to further improve crack-healing efficiency.

Precise Regulation of Reactive Oxygen Species in Tumor Microenvironment for Alleviating Inhibitory Immunogenic Cell Death.

High level of C (ROS) within the tumor microenvironment (TME) not only damage tumor cells but also diminish the efficacy of immunogenic cell death (ICD) and the activity of tumor-infiltrating T lymphocytes, thereby limiting the effectiveness of immunotherapy. Therefore, precise modulation of ROS level is crucial to effectively eliminate tumor cells and activate ICD-induced immunotherapy. Here, an intelligent yolk shell nanoplatform (SPCCM) that features calcium carbonate shells capable of decomposing under acidic TME conditions, thereby releasing the natural antioxidant proanthocyanidins (PAs) and the photosensitizer Ce6 is designed. PAs scavenge ROS within tumors, extending the survival time of T lymphocytes, while Ce6, as an ICD inducer, generates high ROS concentrations upon laser irradiation, thus reaching the toxic threshold within tumor cells and inducing apoptosis. The resulting apoptotic cells serve as tumor-associated antigens, promoting dendritic cells (DCs) maturation, and activating ICD. By effectively neutralizing ROS in the TME, PAs sustainably reduce ROS level, thereby enhancing DCs activation and restoring antitumor immune cell activity suppressed by ROS (resulting in an eightfold increase in DCs activation). This study demonstrates effective synergistic effects between photodynamic therapy and immunotherapy by precisely modulating ROS level.

Bioerosion and encrustation in late triassic reef corals from Iran

Hard substrate communities can impact coral reef growth by adding or removing calcium carbonate when they act as encrusters or bioeroders, respectively. Although such sclerobiont communities are known across the Phanerozoic, the Triassic saw a substantial increase in reef macrobioerosion. This study provides the first quantitative assessment of sclerobionts in a Late Triassic (Norian) reef coral community (from the Nayband Formation in central Iran) and establishes some post-Paleozoic trends in reef bioerosion. Sclerobionts were common on the dominant coral Pamiroseris rectilamellosa and covered between 0 and 26.4% of total coral surface area among the 145 colonies investigated. Encrustation was significantly more prevalent (1.78% of total area) than bioerosion (0.36% of total area). The underside of corals was 3.5 times more affected by sclerobionts than the upper surfaces. This suggests that the sclerobionts preferentially colonized dead parts of the corals. The main encrusting taxa were polychaete worms (76.2%), followed by bivalves (11.9%). The main bioeroders were Polychaeta (51.4%), Porifera (22.2%), and Bivalvia (20.7%). The lack of a correlation between encrustation and bioerosion intensity suggests that the number of sclerobionts is not simply a function of exposure time before final burial. Our review of the published literature suggests a declining trend in the relative importance of bivalves, polychaetes and cirripeds in reefs, whereas sponges increased in importance from the Triassic until today.

Enhancing carbon mineralization of slag leachate using amine-functionalized magnetic nanoparticle clusters

Carbon mineralization—converting carbon dioxide (CO2) into stable carbonate minerals, such as calcium carbonate (CaCO3)—has attracted much attention as a permanent way to sequester CO2. In this study, we developed a novel method for improving the efficiency of carbon mineralization using amine-functionalized magnetic nanoparticle clusters (A-MNCs). To prepare them, magnetic nanoparticle clusters composed of tens of small Fe3O4 nanoparticles were treated with 3-aminopropyltriethoxysilane to functionalize amine groups on their surfaces. When CO2 was bubbled into a NaOH solution, the rate of CO2 dissolution was enhanced in the presence of A-MNCs, mostly due to physical effects such as grazing and hydrodynamic effects that improved mass transfer between the solution and CO2 bubbles. In addition, A-MNCs promoted carbon mineralization in a NaOH solution containing Ca2+ by providing an additional mineralization route via carbamate formation, resulting in a threefold increase in efficiency to 81 %. We demonstrated that A-MNCs could be applied to leachate from slag, a byproduct of commercial steelmaking, increasing the efficiency by 2.6 times compared to the absence of A-MNCs. The resulting CaCO3 precipitate was confirmed to be calcite using X-ray diffraction and scanning electron microscopy. Furthermore, after the mineralization, A-MNCs were easily separated from the solution using a permanent magnet, while retaining their performance.

CT image-based simulation of microbially induced carbonate precipitation

Soil improvement efforts occasionally negatively impact the delicate balance of the natural environment and disrupt ecosystems. Thus, adopting ecologically sensitive techniques that can harmoniously safeguard the Earth is imperative. Recently, researchers have focused on microbially induced carbonate precipitation (MICP), an eco-friendly soil enhancement method that fosters increased interparticle cohesion and augments the mechanical strength of soil. The spatial distribution of calcium carbonate precipitation in MICP-treated soil can be observed using scanning electron microscopy and X-ray computed tomography (CT). However, since this precipitation occurs in the microscopic region, it cannot be directly observed over time. Therefore, in this study, we propose a simulation technique to replicate the MICP process using a voxel dataset obtained via X-ray CT analysis. The calculated patterns of calcium carbonate were distributed on the soil particles in the same manner as the spatial precipitation observed in the experiments. Notably, some precipitates bridged the soil particles, indicating that the proposed technique could morphologically estimate the calcium carbonate distribution through MICP. Evidently, the proposed technique could accurately simulate MICP phenomena. Furthermore, the results showed that the proposed technique can effectively express a multidiscliplinary phenomenon. Therefore, the study can inspire further studies that employ such techniques to investigate MICP.

Carbonated calcium silicates as pozzolanic supplementary cementitious materials

This study examined the carbonation mechanisms and products of various precursors, including hydrated cement pastes and calcium silicate clinkers. Regardless of the materials investigated, all exhibited rapid carbonation reactions and achieved high degrees of carbonation. Calcium carbonate and siliceous gel were consistently formed as carbonation products. The starting materials significantly influenced the characteristics of the siliceous gel. Carbonated concrete pastes displayed a higher presence of alumina in the gel, resulting in greater surface area and nano-porosity compared to gels formed from calcium silicate clinkers. The pozzolanic reaction products also differed depending on the precursor, with carbonated concrete pastes forming C-S-H and AFm phases, while carbonated calcium silicate clinkers produced only C-S-H phase. Such variations impacted the evolution of mechanical performance in composite cements. Notably, carbonated composite cements containing recycled concrete pastes exhibited higher early compressive strength compared to carbonated calcium silicate clinkers. However, the final compressive strength is similar.

Cell-Based Meat Scaffold Based on a 3D-Printed Starch-Based Gel.

Starch was mixed with a gel to produce a starch-based gel ink, which exhibited favorable printing characteristics. Through the optimization of infill density, 3D-printed scaffolds with 50% infill density and a highly ordered microstructure were successfully fabricated. The addition of calcium carbonate nanoparticles-glucono delta lactone (CaCO3 NPs-GDL) had notable effects on the swelling degree, in vitro digestion, water stability, and pore distribution of the scaffolds. When the amount of CaCO3 NPs in the starch-based gel was 0.075 g, the resulting 3D-printed gel scaffold with a 50% infill density proved to be the most suitable for cultivating cell-based meat. It featured pore sizes ranging from 80 to 120 μm and a compression modulus of 246.76 Pa. After 7 days of proliferation, the C2C12 mouse skeletal myoblasts exhibited an approximately 2.81-fold increase in cell numbers. The fusion index and maturation index of C2C12 cells on the scaffolds were 57.00 ± 0.45% and 34.56 ± 0.56%, respectively. The starch-based gel scaffolds demonstrated excellent water stability and in vitro degradability. Moreover, C2C12 cells exhibited successful proliferation and differentiation on the starch-based scaffolds, ultimately leading to the production of cell-based meat. This study developed a starch-based composite gel scaffold for the manufacture of cell-based meat.

Acidity-Responsive Fe-PDA@CaCO3 Nanoparticles for Photothermal-Enhanced Calcium-Overload- and Reactive-Oxygen-Species-Mediated Tumor Therapy.

Calcium-overload-mediated tumor therapy has received considerable interest in oncology. However, its efficacy has been proven to be inadequate due to insufficient calcium ion concentration at the tumor site coupled with challenges in facilitating efficient calcium uptake by tumors, leading to unsatisfactory therapeutic outcomes. In the present study, calcium carbonate nanoshell mineralized ferric polydopamine nanoparticles (Fe-PDA@CaCO3 NPs) were prepared for achieving Ca2+-overload-mediated tumor therapy. Upon entering the tumor site, the pH-responsive CaCO3 layer, acting as a "Ca2+ storage pool", rapidly degraded and released high quantities of free Ca2+ within the weakly acidic environment. The Fe-PDA core, with its excellent photothermal conversion properties, could significantly increase the temperature upon exposure to near-infrared (NIR) light irradiation, thereby activating the TRPV1 channel and leading to a large influx of released Ca2+ into the cytoplasm. Furthermore, the exposed Fe-PDA core could react with the tumor-overexpressed hydrogen peroxide (H2O2) to efficiently produce hydroxyl radicals (•OH), significantly increasing intracellular reactive oxygen species (ROS) levels and thus inhibiting the activity of the Ca2+ efflux pump, resulting in a high intracellular Ca2+ concentration. Ultimately, the increase in calcium/ROS levels could disrupt mitochondrial homeostasis and activate the apoptosis pathway. The current work presents a promising approach for tumor therapy using photothermal-enhanced calcium-overload-mediated ion interference therapy and chemodynamic therapy.

Live imaging of center of calcification formation during septum development in primary polyps of Acropora digitifera

Recent studies have revealed that stony corals create their extracellular skeletons via biologically controlled calcification, in which amorphous calcium carbonate (ACC), regarded as precursors of aragonite crystals, have been observed at nanoscale using electron microscopy. However, the exact mechanism by which ACC is generated, and how it contributes to skeletal growth in coral calcifying tissue, remains enigmatic. The septal skeleton of an individual polyp is composed of radially aligned plates extending upward from the aboral calcifying tissue. This structure includes microstructure known as the centers of calcification (CoC). However, despite its importance, direct in vivo observation of septal growth has not been reported. Observations under transmitted illumination using polarized light microscopy on calcifying tissue of young Acropora digitifera revealed small crystals, a few micrometers in size, that accompany subtle movements and that emerge exclusively on the inner wall of the pocket in extracellular calcifying fluid (ECF). Crystal growth initiated from small, scattered crystals on a glass plate resembles this phenomenon observed in coral skeletons. Time-lapse photographs of 12 individuals in early primary polyp settlement revealed this process in three individuals, documenting 13 of these crystal events. This phenomenon occurred solely at the bases of subsequently formed septa. These crystals differ notably from fusiform crystals and from dumbbell-like or rod-like crystals growing individually. Upright two-photon microscopy captured movement of sub-micron-sized fluorescent calcein-accumulating particles, emphasizing their presence on the surface of the growing fronts of septa. Methodological advances that facilitate comprehensive in vivo observation of sub-micron-sized structures, calcein-accumulating particles to the skeleton, are needed to develop a more detailed understanding of coral skeletal growth.

Design and evaluation of alkali-activated slag-calcined coal gangue cement and the shrinkage control by calcium carbonate whisker

The rapid solidification and significant shrinkage of alkali-activated slag cement are key issues that restrict its practical engineering application. This paper explores the composition design of alkali-activated cements (AAC) with slow coagulation and shrinkage reduction. This paper adjusts the proportion of slag (SG) and calcined coal gangue powder (CCGP), regulates the content of Na2O·2.4SiO2-NaOH-Na2CO3 ternary activator components, and uses calcium carbonate whiskers (CW) instead of SG to prepare AAC with slow coagulation and shrinkage reduction. When the activator is composed of (66 %) Na2O·2.4 SiO2-(2 %) NaOH-(32 %) Na2CO3 mixed composition, the CO32- and Ca2+ in the system react preferentially to produce CaCO3. The decrease of Ca2+ concentration delays the formation of C-(A)-S-H, resulting in the initial and final setting time of AAC reaching 334 min and 346 min, respectively. When the CW substitution rate is 3 %, the 28d compressive strength of AAC reaches 102.2 MPa. The 49d drying shrinkage of the AAC is 7020μm/m and the 49d autogenous shrinkage is 2387μm/m. This is attributed to the combined effect of enhancement mechanisms such as whisker bridging, crack deflection, whisker pullout, whisker–matrix coalition pullout and whisker breakage. This study establishes the relationship between the composition and performance of high performance AAC, which is significance for the resource utilization of coal gangue and the practical engineering application of AAC.

Co-hydrothermal carbonization of waste biomass and phosphate rock: promoted carbon sequestration and enhanced phosphorus bioavailability

Co-hydrothermal carbonization (co-HTC) of phosphorus rock (PR) and corn straw (CS) was investigated to prepare hydrochar-based materials as soil conditioners, focusing on the morphological transformation and solid–liquid migration of carbon and phosphorus. Various analytical methods, including elemental analysis, chemical quantification, FT-IR, XRD, 3D-EEM, TG, and XANES, were used to understand the synergistic interactions of PR and CS during co-HTC and determine the properties of the resultant products. The results indicated the acidic solution and humic acid-like substances produced by HTC of CS reduced the crystallinity of the PR and served as the activating agent for PR, allowing the PR to be easily dissolved and reconstituted, producing calcium carbonate and apatite-like materials, and the formation of C–O–PO3, C–PO3, C=O, and O=C–O chemical bonds. At 220 °C, adding 5% PR significantly promoted a 10.3% rise in the yield of CS hydrochar, a 4.3% rise in carbon recovery of CS, and a 4.8% rise in carbon sequestration potential of CS. The formation of Ca–P was notably promoted and the content of AP in co-HTC hydrochar was up to 89.9%, with 39% Hydro-P and 33% CaHPO4. In the case of artificial humic acid (HAa), its content was also remarkably increased by 5.9% in the hydrochar by co-HTC. In addition, the hydrochar produced by co-HTC of CS and PR was composed of carbon with an increased aromatic degree, rich organic matter, and biologically effective mineral nutrient elements and exhibited high stability. The present study provided a promising approach for value-added utilization of waste biomass and low-grade PR towards soil application.Graphical

Enhanced steel corrosion inhibition through microbially induced carbonate precipitation with facultative anaerobic denitrifying bacterium

Denitrification processes are increasingly studied as a promising alternative to ureolytic microbially induced carbonate precipitation (MICP). This study investigates the capabilities of the newly isolated denitrifying bacterium, Stutzerimonas stutzeri CF3, in promoting calcium carbonate precipitation and enhancing steel corrosion resistance under both aerobic and anaerobic conditions. The facultative anaerobe was tested across a range of environmental parameters including pH levels (7.5–11.5), C/N ratios (5−15), NaCl salinity (0–5 %), and Ca²⁺ concentrations (0–30 mmol), to determine its adaptability and effectiveness in precipitating calcium carbonate. Our findings reveal that S. stutzeri CF3 not only survives but thrives under extreme conditions, demonstrating significant nitrate removal and robust calcium carbonate precipitation, particularly in high salinity and variable pH environments. Furthermore, the study examines the implications of S. stutzeri CF3 on steel corrosion, particularly Q235 steel, using Tafel polarization techniques, demonstrating enhanced corrosion resistance. These results underscore the dual utility of S. stutzeri CF3 in microbial self-healing concrete applications, pointing to its potential to improve the durability and integrity of construction materials by leveraging its versatile metabolic pathways.

Low-Cost and Eco-Friendly Calcium Oxide Prepared via Thermal Decompositions of Calcium Carbonate and Calcium Acetate Precursors Derived from Waste Oyster Shells

Waste oyster shells were utilized to produce calcium carbonate (CaCO3) by grinding. This CaCO3 was then reacted with acetic acid to yield calcium acetate monohydrate (Ca(CH3COO)2·H2O). Both CaCO3 and Ca(CH3COO)2·H2O were used as precursors for synthesizing calcium oxide (CaO) through thermal decomposition at 900 °C and 750 °C, respectively. The yields of CaO from both precursors, determined through calcination experiments and thermogravimetric analysis (TGA), exceeded 100% due to the high purity of the raw agents and the formation of calcium hydroxide (Ca(OH)2). X-ray fluorescence (XRF) analysis revealed a CaO content of 87.8% for CaO-CC and 91.5% for CaO-CA, indicating the purity and contamination levels. X-ray diffraction (XRD) patterns confirmed the presence of CaO and minor peaks of Ca(OH)2, attributed to moisture adsorption. Fourier-transform infrared (FTIR) spectroscopy identified the vibrational characteristics of the Ca-O bond. Scanning electron microscopy (SEM) showed similar morphologies for both CaO-CC and CaO-CA, with CaO-CA displaying a significant amount of rod-like crystals. Based on these results, calcium acetate monohydrate (CA) is recommended as the superior precursor for synthesizing high-purity CaO, offering advantages for various applications.

Triple effective water treatment agent: P(AA/AMPS) capped sulfur quantum dots boast remarkable antiscale, antibacterial, and real-time tracking capabilities

Recent research has explored nanomaterials as sustainable scale inhibitors for water treatment. This research specifically delved into the development of environmentally benign antimicrobial sulfur quantum dot scale inhibitors (P(AA/AMPS)-SQDs) by capping P(AA/AMPS) with varying molecular weights. The synthesized P(AA/AMPS)-SQDs underwent thorough characterization employing high-resolution transmission electron microscopy, X-ray photoelectron spectroscopy, and zeta potential analysis. The inhibitory efficacy of P(AA/AMPS)-SQDs on calcium carbonate (CaCO3) and calcium sulfate (CaSO4) scale formation was conducted under diverse conditions, including scale inhibitor concentration, reaction time, temperature, and pH using scanning electron microscopy and X-ray powder diffraction techniques. Remarkably, the water agent P(AA/AMPS)-SQDs showcased exceptional fluorescence, water solubility, and resilience to high temperatures. At specified concentrations, P(AA/AMPS)-SQDs demonstrated remarkable inhibition efficiencies, with over 98 % inhibition against the CaCO3 scale at 20 mg/L and over 97 % inhibition against the CaSO4 scale at 0.5 mg/L, significantly outperforming traditional scale inhibitors. Furthermore, P(AA/AMPS)-SQDs exhibited almost 100 % inhibition efficiency against Bacillus subtilis at a dosage of 150 mg/L. Furthermore, molecular dynamics simulation and quantum chemical calculations were employed to clarify the scale inhibition mechanisms of P(AA/AMPS)-SQDs. This multifunctional water treatment agent, integrating scale inhibition, antimicrobial properties, and online monitoring capabilities, lays a solid foundation for potential applications in engineering domains.

Effects of urease and cementing solution concentrations on micro-scale enzymatic mineralisation characteristics

Enzymatically induced carbonate precipitation holds significant promise in geotechnical engineering. The concentrations of urease enzyme and cementing solution play vital roles in precipitation behaviours under distinct injection strategies. In situ microscale experiments, conducted in S-shaped microchips, were aimed at exploring precipitation distribution characteristics and micro-clogging effects due to biological precipitation. In the one-phase continuous injection methods, elevated urease concentrations correlated with increased amorphous calcium carbonate formation and more heterogeneous distributions. Conversely, lower cementing solution concentrations produced larger, fewer crystals and more uniform distributions. Higher urease improved efficiency but increased cost, while lower cementing solution concentrations displayed efficient performance. Permeability reduction exhibited a power-law relationship with the precipitation area fraction. In the two-phase staged injection method, elevated urease concentrations fostered more regularly shaped crystals. Higher calcium ion concentrations could inhibit ureolysis rate, reducing precipitates. Higher urease concentrations proved beneficial in improving efficiencies. Permeability exhibited a marginal decrease initially, followed by a significant decline as the precipitation area fraction increased. The results offer microscale insights into concentration effects, aiding the understanding of upscaling mechanisms and numerical simulations.

Customizable Hydrogel Coating of ECM-Based Microtissues for Improved Cell Retention and Tissue Integrity

Overcoming the oxygen diffusion limit of approximately 200 µm remains one of the most significant and intractable challenges to be overcome in tissue engineering. The fabrication of hydrogel microtissues and their assembly into larger structures may provide a solution, though these constructs are not without their own drawbacks; namely, these hydrogels are rapidly degraded in vivo, and cells delivered via microtissues are quickly expelled from the area of action. Here, we report the development of an easily customized protocol for creating a protective, biocompatible hydrogel barrier around microtissues. We show that calcium carbonate nanoparticles embedded within an ECM-based microtissue diffuse outwards and, when then exposed to a solution of alginate, can be used to generate a coated layer around the tissue. We further show that this technique can be fine-tuned by adjusting numerous parameters, granting us full control over the thickness of the hydrogel coating layer. The microtissues’ protective hydrogel functioned as hypothesized in both in vitro and in vivo testing by preventing the cells inside the tissue from escaping and protecting the microdroplets against external degradation. This technology may provide microtissues with customized properties for use as sources of regenerative therapies.

Antiscaling Pickering Emulsions Enabled by Amphiphilic Hairy Cellulose Nanocrystals.

Nucleation and growth of sparingly soluble salts, referred to as scaling, has posed substantial challenges in industrial processes that deal with multiphase flows, including enhanced oil recovery (EOR). During crude oil extraction/recovery, seawater is injected into oil reservoirs and yields water-in-oil (W/O) emulsions that may undergo calcium carbonate (CaCO3) scaling. Common antiscaling macromolecules and nanoparticles have adverse environmental impacts and/or are limited to functioning only in single-phase aqueous media. Here, we develop a novel antiscaling cellulose-based nanoparticle that enables scale-resistant Pickering emulsions. Cellulose fibrils are rationally nanoengineered to yield amphiphilic hairy cellulose nanocrystals (AmHCNC), bearing hydrophilic dicarboxylate groups and hydrophobic alkyl chains on disordered cellulose chains (hairs) protruding from nanocrystal ends. The unique chemical and structural properties of AmHCNC render them the first dual functional antiscaling and emulsion stabilizing nanoparticle. AmHCNC stabilize W/O Pickering emulsions at a concentration of 1.00 wt % for 1 week while inhibiting CaCO3 scale formation up to 70% by mass at a supersaturation degree of ∼101 compared with the synthetic surfactant Span 80. To the best of our knowledge, this study presents the first biopolymer-based solution for the long-lasting scaling challenge in multiphase media, which may set the stage for developing sustainable scale-resistant multiphase flows in a broad spectrum of industrial sectors.

Enhanced breast cancer therapy using multifunctional lipid-coated nanoparticles combining curcumin chemotherapy and nitric oxide gas delivery

The limitations associated with conventional cancer treatment modalities, particularly for breast cancer, underscore the imperative for developing safer and more productive drug delivery systems. A promising strategy that has emerged is the combination of chemotherapy with gas therapy. We synthesized curcumin-loaded amorphous calcium carbonate nanoparticles (Cur-CaCO3) via a gas diffusion reaction in the present study. Subsequently, a "one-step" ethanol injection method was employed to fabricate lipid-coated calcium carbonate nanoparticles (Cur-CaCO3@LA-Lip) loaded with L-arginine, aimed at harnessing the synergistic effects of chemotherapy and nitric oxide to enhance antitumor efficacy. Transmission electron microscopy analysis revealed that Cur-CaCO3@LA-Lip nanoparticles were subspherical with a distinct lipid layer encapsulating the periphery. Fourier transform infrared spectroscopy, X-ray powder diffraction, and differential scanning calorimetry results confirmed the successful synthesis of Cur-CaCO3@LA-Lip. The nanoparticles exhibited significant drug loading capacities of 8.89% for curcumin and 3.1% for L-arginine. In vitro and in vivo assessments demonstrated that Cur-CaCO3@LA-Lip nanoparticles facilitated sustained release of curcumin and exhibited high cellular uptake, substantial tumor accumulation, and excellent biocompatibility. Additionally, the nanoparticles showed robust cytotoxicity and potent antitumor efficacy, suggesting their potential as a formidable candidate for breast cancer therapy.