Self-fueling ferroptosis-inducing microreactors based on pH-responsive Lipiodol Pickering emulsions enable transarterial ferro-embolization therapy

Lipiodol chemotherapeutic emulsions remain one of the main choices for the treatment of unresectable hepatocellular carcinoma (HCC) via transarterial chemoembolization (TACE). However, the limited stability of Lipiodol chemotherapeutic emulsions would lead to rapid drug diffusion, which would reduce the therapeutic benefit and cause systemic toxicity of administrated chemotherapeutics. Therefore, the development of enhanced Lipiodol-based formulations is of great significance to enable effective and safe TACE treatment. Herein, a stable water-in-oil Lipiodol Pickering emulsion (LPE) stabilized by pH-dissociable calcium carbonate nanoparticles and hemin is prepared and utilized for efficient encapsulation of lipoxygenase (LOX). The obtained LOX-loaded CaCO3&hemin-stabilized LPE (LHCa-LPE) showing greatly improved emulsion stability could work as a pH-responsive and self-fueling microreactor to convert polyunsaturated fatty acids (PUFAs), a main component of Lipiodol, to cytotoxic lipid radicals through the cascading catalytic reaction driven by LOX and hemin, thus inducing ferroptosis of cancer cells. As a result, such LHCa-LPE upon transcatheter embolization can effectively suppress the progression of orthotopic N1S1 HCC in rats. This study highlights a concise strategy to prepare pH-responsive and stable LPE-based self-fueling microreactors, which could serve as bifunctional embolic and ferroptosis-inducing agents to enable proof-of-concept transarterial ferro-embolization therapy of HCC.

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

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

Plasmid encoding miRNA-200c delivered by CaCO3-based nanoparticles enhances rat alveolar bone formation

Aim: miRNAs have been shown to improve the restoration of craniofacial bone defects. This work aimed to enhance transfection efficiency and miR-200c-induced bone formation in alveolar bone defects via plasmid DNA encoding miR-200c delivery from CaCO₃ nanoparticles. Materials & methods: The CaCO₃/miR-200c delivery system was evaluated in vitro (microscopy, transfection efficiency, biocompatibility) and miR-200c-induced in vivo alveolar bone formation was assessed via micro-computed tomography and histology. Results: CaCO₃ nanoparticles significantly enhanced the transfection of plasmid DNA encoding miR-200c without inflammatory effects and sustained miR-200c expression. CaCO₃/miR-200c treatment in vivo significantly increased bone formation in rat alveolar bone defects. Conclusion: CaCO₃ nanoparticles enhance miR-200c delivery to accelerate alveolar bone formation, thereby demonstrating the application of CaCO₃/miR-200c to craniofacial bone defects.

Design and development of CaCO3nanoparticles enhanced fracturing fluids for effective control of leak-off during hydraulic fracturing of shale reservoirs

This research presents new information about the nanoparticles (NPs) use as a filtrate reducer in the hydraulic fracturing of shale reservoirs. An experimental study was conducted to determine the filtration loss control effectiveness (FLCE) of CaCO₃NPs as an additive in fluids used for hydraulic fracturing of the shale reservoirs. The main objectives were (i-) to determine the mechanisms controlling the NPs enhanced fracturing fluid leak-off rate; (ii-) to determine the optimum NPs concentration, which yields the best FLCE. Spontaneous and forced imbibition experiments (to determine imbibition index) as well as the pressure transmission tests (to determine liquid permeability) were conducted using water based fracturing fluids enhanced by CaCO₃NPs. The imbibition index and the apparent liquid permeability measurements were then used to determine the impact of the NPs concentration (i.e. 0.0, 0.5, 1.0, 2.0 wt%) on the FLCE. In order to understand the filtration control mechanisms of the NPs enhanced fracturing fluids, we have analyzed the field emission scanning electron microscope (FESEM) images of the shale samples, which provided detailed description of how NPs are attached to the shale surface. The experimental results indicated that the CaCO₃NPs have excellent FLCE. The imbibition index and the apparent liquid permeability decreased significantly along with the increasing NPs concentration. The optimum NPs concentration was found to be 1.0 wt%. Analyses of the FESEM images demonstrated that the distribution of the NPs on shale surface is selective. The NPs mainly attached on the rough areas of the shale surface. The process of the NPs adsorption-sealing leads to the reduction of the path of the fluid flow into the shale matrix, and in turn, controls the fracturing fluid filtration. Ultimately, four kinds of sealing patterns were observed including (i-) plugging, (ii-) bridging, (iii-) plugging and accumulation, (iv-) bridging and accumulation.

Effect of CaCO₃ Nanoparticles on the Mechanical and Photo-Degradation Properties of LDPE

CaCO₃ nanoparticles of around 60 nm were obtained by a co-precipitation method and used as filler to prepare low-density polyethylene (LDPE) composites by melt blending. The nanoparticles were also organically modified with oleic acid (O-CaCO₃) in order to improve their interaction with the LDPE matrix. By adding 3 and 5 wt% of nanofillers, the mechanical properties under tensile conditions of the polymer matrix improved around 29%. The pure LDPE sample and the nanocomposites with 5 wt% CaCO₃ were photoaged by ultraviolet (UV) irradiation during 35 days and the carbonyl index (CI), degree of crystallinity (χ_c), and Young’s modulus were measured at different times. After photoaging, the LDPE/CaCO₃ nanocomposites increased the percent crystallinity (χ_c), the CI, and Young’s modulus as compared to the pure polymer. Moreover, the viscosity of the photoaged nanocomposite was lower than that of photoaged pure LDPE, while scanning electron microscopy (SEM) analysis showed that after photoaging the nanocomposites presented cavities around the nanoparticles. These difference showed that the presence of CaCO₃ nanoparticles accelerate the photo-degradation of the polymer matrix. Our results show that the addition of CaCO₃ nanoparticles into an LDPE polymer matrix allows future developments of more sustainable polyethylene materials that could be applied as films in agriculture. These LDPE-CaCO₃ nanocomposites open the opportunity to improve the low degradation of the LDPE without sacrificing the polymer’s behavior, allowing future development of novel eco-friendly polymers.

Preparation and characterization of PSF/PEI/CaCO3 nanocomposite membranes for oil/water separation

Ultrafiltration (UF) is one of the significant advanced processes for oily wastewater treatment due to its clear advantages, for instance, ease in operation and efficient separation. The main drawback of these processes is the fouling problem and many researchers' effort on fabrication of high-performance membranes with higher hydrophilicity and antifouling properties. In this study, flat-sheet polysulfone (PSF)/polyethylenimine (PEI)/CaCO₃ nanocomposite membranes were prepared by phase inversion method for oil/water emulsion separation. Structural properties of membranes were characterized by SEM, FT-IR, contact angle, tensile strength, and atomic force microscopy analysis. Increasing the CaCO₃ nanoparticle loading exhibited the increased the water flux and BSA rejection. PSF/PEI/10 wt% CaCO₃ nanocomposite membranes have 145 L/m² h water flux at 2 bar with a contact angle of 84° and with 92% BSA rejection. All prepared CaCO₃ nanocomposite membranes reached similar oil rejections at above 90%. Besides the higher water flux and oil removal efficiencies, 10 wt% of CaCO₃ nanoparticle-blended PSF membranes has notable antifouling capacity with the highest flux recovery ratio (FRR) and lowest flux decay ratio (DR) values. The results showed that there is a great potential to use PSF/PEI/CaCO₃ nanocomposite membranes for the treatment of oil water emulsions with higher permeability and antifouling capacity.