Good Dispersion Research Articles

Synergistic hybrid effect of nano fillers on the structure and properties of asphalt composites

ABSTRACT The CNTs/nano ZnO/SBS/asphalt composites with different CNTs content were prepared by solution casting method. The morphology of the composite shows that the dispersion of SBS is improved by the synergistic hybrid effect of CNTs and nano ZnO. Good dispersion is beneficial for enhancing the adsorption of lightweight components, thereby effectively improving the temperature range of asphalt use. At the same time, the increase in the proportion of asphaltene leads to an increase in the number of honeycomb structures, the surface roughness of composite materials, as well as the water contact angle.

Enhancement of ammonia corrosion resistance of coatings through improving dispersion and binding site of graphene oxide in silane coatings

Copper metal is essential to our production process, but it is highly corrosive in an ammonia environment and must be highly valued. Anti-corrosion coating is a simple and cost-effective method of preventing metal corrosion. In this study, a composite silane coating was prepared on copper using an impregnation method with mercaptopropyltriethoxysilane (TPTES) as the silane substrate and graphene oxide (GO) modified with isophorone diisocyanate (IPDI) or isocyanatopropyltriethoxysilane (IPTS) as filler to protect the copper from ammonia corrosion. The coating samples were hanging tested against ammonia corrosion by setting up two corrosive environments: ammonia gas and ammonia water. After 20 days of corrosion, the surfaces of the TPTES/IPDI-GO and TPTES/IPTS-GO coatings remained unchanged under both ammonia environments and the corrosion rate was consistently low at 2–3 μm/y. Additionally, the coating exhibited high protective qualities according to the electrochemical impedance spectroscopy (EIS) test in a 3.5% NaCl solution, which is attributed to the good dispersion that improves the densification and regularity of the coating. Meanwhile, IPTS-GO has a greater binding force with the coating matrix due to the increased number of reactive sites, resulting in further improved corrosion protection. This study provides an idea for research on ammonia-resistant coatings.

MICROSTRUCTURE OF CB/SIO2 HYBRID REINFORCED SOLID TYRE TREAD COMPOUND CONTAINING GROUND TYRE RUBBER AND THEIR EFFECT ON FATIGUE RESISTANCE

The possibility of improving the properties of rubber compounds containing ground tyre rubber (GTR) is an active research area. This study investigates the microstructure of carbon black filled tyre tread compound containing 20 phr GTR and compares the microstructure with those of similar compounds reinforced with hybrid carbon black/precipitated silica (CB/SiO2). In the compounds reinforced with hybrid filler, amount of the GTR was maintained at 20 phr, while the amount of the hybrid filler (CB/SiO2 ) were in the ratios 55/5, 50/10 and 45/15 respectively. The compounds were mixed by two-step mixing method using internal mixer and two-roll mill. The vulcanisation of each rubber compound was carried out on a compression moulding machine at 150. Results obtained from scanning electron microscopy of the fractured surfaces showed that the ingredients in the control sample that was not filled with GTR were well dispersed and distributed. The micrograph of the sample containing GTR and mixed at 60 showed that GTR was not very compatible with the matrix. Improved mixing was achieved with increased mixing temperature. The addition of precipitated silica at 5 phr resulted in poor dispersion. The dispersion improved as the amount of silica increased to 10 phr and 15 phr respectively. Results obtained from flex fatigue test show that the compounds filled with hybrid CB/SiO2 in the ratios 50/10 and 45/15 phr exhibited no crack after 1000 cycles due to good dispersion. It is recommended that hybrid CB/SiO2 reinforcement at optimal amount of silica should be utilised to fill rubber compounds containing GTR in order to improve the properties of the vulcanisates.

Three-in-one novel flame retardant through grafting organophosphorus onto Fe-MOF functionalized Mg(OH)2 for improving fire safety and mechanical properties of PBS composites

As one typically sustainable polymer material, poly(butylene succinate) (PBS) is highly necessary to improve its flame retardancy and simultaneously maintain satisfied mechanical performances. In this study, “three-in-one” novel flame retardant was synthesized through grafting organophosphorus onto Fe-MOF functionalized Mg(OH)2 (labeled as MH@Fe-MOF-P), then it was introduced into PBS matrix to investigate its effect on flame retardancy and mechanical properties. The results indicated that PBS/20MH@Fe-MOF-P exhibited excellent flame retardancy, including that the LOI was 29.6%, the UL-94 rating reached to V0, and the peak of heat release rate (PHRR) decreased by 82.1%. The flame retardant mechanism was ascribed to the synergistic effect of Mg(OH)2, Fe-MOF and organophosphorus on delaying the decomposition and catalyzing the carbonization of PBS. Meanwhile, PBS/20MH@Fe-MOF-P presented better mechanical performances than PBS/20MH and PBS/20MH@Fe-MOF composites, resulting from the special structure of MH@Fe-MOF-P to achieve good dispersion of fillers and strong polymer-filler interface adhesion. This work provides a novel strategy to modify Mg(OH)2 with high flame retardant efficiency, and also broadens the practical applications of PBS materials with balanced comprehensive performances.

The addition of SiO2-GO hybrid material enhanced the tribological properties of fluorocarbon resin in marine corrosive environments

Fluorocarbon resin (FC), as a commonly used topcoat material for coating systems, is susceptible to the combined effects of seawater corrosion and ocean current erosion when working in marine environments for a long time, often causing hard particle wear and damage. In order to improve the tribological properties of FC resin, graphene oxide (GO) was modified by sol-gel method, and SiO2-GO hybrid nanomaterials and SiO2-GO/FC composite coatings were innovatively prepared. Through a 50 days long-term immersion experiment, the friction coefficient and wear rate of the composite coating were characterized. The study showed that the addition of SiO2-GO effectively reduced the friction coefficient and wear rate of the coating before corrosion immersion. The average friction coefficient of 0.4 wt% SiO2-GO/FC under a 10 N load for 15 minutes was 0.172, and the wear rate was 1.19×10−4 mm3/Nm, a decrease of 69.9% compared to pure FC coating. After long-term immersion, an oxide layer generally appeared between the coating and the substrate. On the 50th day of immersion, FC, GO/FC, 0.2 wt% SiO2-GO/FC, and 0.6 wt% SiO2-GO/FC all lost their protective ability, while 0.4 wt% SiO2-GO/FC maintained basic tribological properties due to its excellent corrosion resistance. This was mainly due to the lubrication characteristics and good dispersibility of SiO2-GO, which endowed the coating with stronger wear resistance. In addition, the maze effect formed by SiO2-GO within the coating reduced corrosion damage, indirectly improving the tribological performance of the coating.

Memory device based on MoS2-polyvinyl alcohol for simulating synaptic behavior

A memory device based on MoS2-polyvinyl alcohol was fabricated. As a good dispersant, polyvinyl alcohol solution can disperse 2D layered materials more evenly in the solution. The 19 states of the device conductance are modulated step by step by direct current scanning, which makes it possible to perform the computing task in memory. Then, the presence of conductive filaments allows the resistance state of the memristor to be dynamically transformed, which is similar to some basic behavior of biological synapses. Further, a variety of conductivity states such as short-term potentiation, short term depression, long term potentiation and long-term depression behavior are modulated by applying voltage to simulate the basic behavior of biological synapses. Finally, the paired pulse facilitation, paired pulse depression, spiking timing dependent plasticity and spiking voltage dependent plasticity behaviors of biological synapses are simulated in memristor devices.

High-Density Au Anchored to Ti3C2-Based Colorimetric-Fluorescence Dual-Mode Lateral Flow Immunoassay for All-Domain-Enhanced Performance and Signal Intercalibration.

In this work, a novel MXene-Au nanoparticle (Ti3C2@Au) was synthesized with a high molar extinction coefficient, strong fluorescence quenching ability, ultrahigh antibody affinity, high stability, and good dispersibility, and it was used to develop a colorimetric-fluorescence dual-mode lateral flow immunoassay (LFIA). The detection limits of this method for the detection of dexamethasone in milk, beef, and pork were 0.0018, 0.12, and 0.084 μg/kg in the "turn-off" mode (colorimetric signal), and 0.0013, 0.080, and 0.070 μg/kg in the "turn-on" mode (fluorescent signal), respectively, which was up to 231-fold more sensitive compared with that of the reported LFIAs. The recovery rates ranged from 81.1-113.7%, and 89.2-115.4%, with the coefficients of variation ranging from 1.4-15.0%, and 1.9-14.8%, respectively. The results of the LC-MS/MS confirmation test on 30 real samples had a good correlation with that of our established method (R2 > 0.97). This work not only developed novel nanocarriers for antibody-based LFIA but also ensured high-performance detection.

Enhanced Adsorption of Methylene Blue Dye on Functionalized Multi-Walled Carbon Nanotubes.

Carbon nanomaterials are promising adsorbents for dye removal from wastewater also due to their possible surface functionalization that, in principle, can increase the adsorption rate and provide regeneration. To investigate the real advantages of functionalization, we synthesized and characterized through IR, TGA, TEM, XPS and DLS measurements a multi-walled carbon nanotube (MWCNT) derivative bearing benzenesulfonate groups (MWCNT-S). The obtained material demonstrated to have good dispersibility in water and better capability to adsorb methylene blue (MB) compared to the pristine MWCNT adsorbent. Adsorption kinetic studies showed a very fast process, with a constant significantly higher with respect not only to that of the unfunctionalized MWCNT adsorbent but also to those of widely used activated carbons. Moreover, the adsorption capacity of MWCNT-S is more than doubled with respect to that of the insoluble pristine MWCNT adsorbent, thanks to the dispersibility of the derivatives, providing a larger available surface, and to the possible electrostatic interactions between the cationic MB and the anionic sulfonate groups. Additionally, the reversibility of ionic interactions disclosed the possibility to release the adsorbed cationic pollutant through competition with salts, not only regenerating the adsorbent, but also recovering the dye. Indeed, by treating the adsorbed material for 1 h with 1 M NaCl, a regeneration capacity of 75% was obtained, demonstrating the validity of this strategy.

Preparation and adjuvanticity against PCV2 of Viola philippica polysaccharide loaded in Chitosan-Gold nanoparticle

The present Porcine circovirus type 2 virus (PCV2) vaccine adjuvants suffer from numerous limitations, such as adverse effects, deficient cell-mediated immune responses, and inadequate antibody production. In this study, we explored the potential of a novel nanoparticle (CS-Au NPs) based on gold nanoparticles (Au NPs) and chitosan (CS) that modified Viola philippica polysaccharide (VPP) as efficient adjuvants for PCV2 vaccine. The characterization demonstrated that CS-Au-VPP NPs had a mean particle size of 507.42 nm and a zeta potential value of −21.93 mV. CS-Au-VPP NPs also exhibited good dispersion and a stable structure, which did not alter the polysaccharide properties. Additionally, the CS-Au-VPP NPs showed easy absorption and utilization by the organism. To investigate their immune-enhancing potential, mice were immunized with a mixture of CS-Au-VPP NPs and PCV2 vaccine. The evaluation of relevant immunological indicators, including specific IgG antibodies and their subclasses, cytokines, and T cell subpopulations, confirmed their immune-boosting effects. The in vivo experiments revealed that the medium-dose CS-Au-VPP NPs significantly elevated the levels of specific IgG antibodies and their subclasses, cytokines, and T cell subpopulations in PCV2-immunized mice. These findings suggest that CS-Au-VPP NPs can serve as a promising vaccine adjuvant due to their stable structure and immunoenhancement capabilities.

Toward a circular economy: zero-waste manufacturing of carbon fiber-reinforced thermoplastic composites

Fiber-reinforced composites are becoming ubiquitous as a way of lightweighting in the wind, aerospace, and automotive industries, but current recycling technologies fall short of a circular economy. In this work, fiber-reinforced composites made of recycled carbon fiber and polyphenylene sulfide were recycled and remanufactured using common processing technologies such as compression and injection molding. An industrially viable size-exclusive sieving technique was used to retain fiber length and reduce variability in the mechanical properties of the remanufactured composites. Fiber length reduction alone could not explain the strength reductions apparent in the composites, which we propose are due to microstructural inhomogeneity as defined by poor dispersion of the fibers. Future recycling efforts must focus on fiber length retention and good dispersion to make composite remanufacturing a viable path toward a circular economy.

Structural and nonlinear J-integral fracture toughness for nanoclay toughened ternary HDPE/LDPE-g-MA/ABS blend nanocomposites

High-density polyethylene (HDPE) has a higher strength-to-density ratio and stiffness but a low branching degree for the packed linear chains that restrict the ability to bond and resist cracking. This study conducts the role of inserting rigid nanoclay (NC) and soft acrylonitrile butadiene styrene (ABS) on the structural, nonlinear fracture toughness and crack resistance of a ternary HDPE/low-density polyethylene-grafted maleic anhydrite (LDPE-g-MA)/ABS blend. Varying additions of 1, 3, 5, and 7 % NC and 5, 10, 15 wt. % ABS were inserted into neat HDPE and HDPE90/LDPE-g-MA10. All materials were hand-mixed before feeding into a single screw extruder and directly melt-blended twice to achieve a good dispersion of nanofiller in the matrix. The structural characteristics and the fracture surfaces of NC/HDPE/LDPE-g-MA and NC/HDPE/LDPE-g-MA/ABS were investigated by TEM, XRD, SEM, and FTIR spectra. Tensile strength and the critical dissipated energy (JIc) determined by quasi-static J-integral fracture mechanic revealed a higher absorbing fracture energy of 75 KJ/m2 for the binary and 85 KJ/m2 for the ternary nanocomposites. The synergistic percolated role of the NC particles and ABS copolymer in front of the crack tip region hinders crack growth for the presence of micro-void coalescence and massive shear-yielding toughening mechanisms.

Synthesis of graphene quantum dots inside a nanoreactor for fluorescence detection of dopamine

A label-free fluorescence sensor for selective detection of dopamine (DA) was developed by using graphene quantum dots (GQDs) as fluorescence probes. The GQDs were prepared via a top-down acid vapor oxidation strategy, in which a hollow carbon @ mesoporous silica nanosphere (h-C@mesoSiO2) serves as nanoreactor and only 1 mL of HNO3 was used as scissors for quickly cleaving the thin carbon layer in the nanospace of h-C@mesoSiO2. The method not only effectively avoids a tedious separation process but also endows GQDs with uniform size and good dispersion. And the as-prepared GQDs display good linear fluorescence response to DA in the range of 0.24–5.86 mM with a low detection limit of 12.7 nM. The proposed sensor shows high selectivity and satisfying recovery for DA detection in human urine. The good specificity toward DA may be due to a) the carboxyl groups on the surface of GQDs can interact with the amine functional groups in DA through electrostatic interactions and b) this specificity is further enhanced by the π–π interaction between GQDs and DA. Importantly, the work not only provides an avenue for the controllable synthesis of GQDs, but also expands the application of GQDs prepared by top-down method to DA sensor.

An efficient process for preparing regenerated magnets by dynamic recovery of Nd-Fe-B sintered magnet sludge

As a new technology for the short-process recovery of Nd–Fe–B sintered magnet sludge, the calcium thermal reduction diffusion method has attracted significant attention due to its low energy consumption, environmental friendliness, and high recovery rate. However, traditional calcium thermal reduction diffusion technology still has issues such as an insufficient reaction between the sludge and reducing agent after increasing the amount of reactants, the use of a large amount of reducing agent, and low recovery efficiency. Therefore, a novel dynamic calcium thermal reduction diffusion technology was proposed, with the calcium reduction diffusion of sludge and calcium undergoing a continuous mixing and diffusion state throughout the entire process, greatly improving the efficiency of the reaction. Compared with the traditional process, the amount of reactants was increased from a few grams to hundreds of grams, and the amount of reducing agent calcium was reduced by 25%. Subsequently, regenerated magnetic powder with a uniform particle size, good dispersion, and excellent magnetic properties was obtained. The saturation magnetization under a 3 T magnetic field was increased by 27.9% compared with the initial sludge. The maximum magnetic energy product of the magnet prepared by doping 50 wt% regenerated magnetic powder was 45 MGOe, which reached the highest level of the regenerated magnets prepared by recycling sludge. What is encouraging that this new technology had the advantage of achieving large-scale production and reducing production costs, providing a potential industrialization solution for the green and efficient recovery of Nd–Fe–B sintered magnet sludge.

The role of organic solvent and nano-additives loading in preparing and characterizing graphene oxide based polystyrene nanocomposites

ABSTRACT In this work, two types of organic solvents: namely, dimethylformamide (DMF) and tetrahydrofuran (THF); were investigated individually to prepare graphene oxide (GO) based polystyrene (PS) nanocomposites. Both were effective exfoliation agents for GO nano-sheets using sonication process. However, DMF showed poor solubility for PS beads compared to THF due to its high boiling point, poor volatility, and the prevailing monomer–monomer interaction rather than monomer–solvent interaction. Hot pressing was not an efficient preparatory approach for those samples prepared by DMF. Hence, solution casting, and THF were adopted to prepare PS and its GO-based nanocomposites. (0.5 and 1.0) wt. % of GO were dispersed homogeneously in PS using different dispersive techniques. Range of properties were tested for the pure polymer and its GO-based nanocomposites prepared by THF. A good dispersion of GO nano-sheets in PS was observed by different microscopic techniques. A significant improvement of mechanical and thermo-mechanical (storage modulus) performances for the polymer nanocomposites (PNCs) were achieved compared to the pure polymer. Young’s modulus for PS/GO nanocomposites was improved by 122% and 143% for GO loadings of 0.5 and 1.0 wt. %; respectively, and storage modulus for the nanocomposites recorded a considerable promotion compared to the pure polymer.

Bioinspired Dynamic Matrix Based on Developable Structure of MXene‐Cellulose Nanofibers (CNF) Soft Actuators

AbstractInspired by natural organisms, soft actuators can convert environmental stimuli into mechanical deformation, making them indispensable for applications in a variety of fields such as soft robotics. MXene, displaying exceptional attributes in conductivity, thermal efficiency, good dispersibility etc., has emerged as a preferred material for high‐performance thermal actuators. However, single actuators struggle to achieve complex tasks realized by intelligent robotic systems. Herein, a bioinspired dynamic matrix is presented utilizing the developable structure of MXene‐cellulose nanofibers (CNF) soft actuators. The inclusion of CNF considerably bolsters the mechanical properties of MXene. The MXene‐CNF film possessed a higher working strain range (≈14%) than pure MXene film (≈2%). The designed developable structures complete the actuating movements. The sensing layer integration with the actuating layer led to an extremely low touch detection limit (0.3 kPa) and expedited actuating‐feedback due to the interaction between contact charging and electrostatic induction. A responsive dynamic matrix containing 3 × 3 soft actuators, completed with a close‐looped sensing‐feedback function, is developed similar to the behavior of the mimosa plant. This mimosa‐inspired dynamic matrix is capable of identifying the source of touch stimuli and providing immediate feedback. This research broadens the potential for enhancing adaptability and intelligence of soft robotic system.

A Study of Hyaluronic Acid's Theoretical Reactivity and of Magnetic Nanoparticles Capped with Hyaluronic Acid.

Hyaluronic acid (HA) has attracted much attention in tumor-targeted drug delivery due to its ability to specifically bind to the CD44 cellular receptor, which is widely expressed on cancer cells. We present HA-capped magnetic nanoparticles (HA-MNPs) obtained via the co-precipitation method, followed by the electrostatic adsorption of HA onto the nanoparticles' surfaces. A theoretical study carried out with the PM3 method evidenced a dipole moment of 3.34 D and negatively charged atom groups able to participate in interactions with nanoparticle surface cations and surrounding water molecules. The ATR-FTIR spectrum evidenced the hyaluronic acid binding to the surface of the ferrophase, ensuring colloidal stability in the water dispersion. To verify the success of the synthesis and stabilization, HA-MNPs were also characterized using other investigation techniques: TEM, EDS, XRD, DSC, TG, NTA, and VSM. The results showed that the HA-MNPs had a mean physical size of 9.05 nm (TEM investigation), a crystallite dimension of about 8.35 nm (XRD investigation), and a magnetic core diameter of about 8.31 nm (VSM investigation). The HA-MNPs exhibited superparamagnetic behavior, with the magnetization curve showing saturation at a high magnetic field and a very small coercive field, corresponding to the net dominance of single-domain magnetic nanoparticles that were not aggregated with reversible magnetizability. These features satisfy the requirement for magnetic nanoparticles with a small size and good dispersibility for long-term stability. We performed some preliminary tests regarding the nanotoxicity in the environment, and some chromosomal aberrations were found to be induced in corn root meristems, especially in the anaphase and metaphase of mitotic cells. Due to their properties, HA-MNPs also seem to be suitable for use in the biomedical field.

Natural Wollastonite-Derived Two-Dimensional Nanosheet Ni3Si2O5(OH)4 as a Novel Carrier of CdS for Efficient Photocatalytic H2 Generation

Ni3Si2O5(OH)4 rods (NS) were synthesized via a hydrothermal method, employing natural wollastonite as a template. The hierarchical Ni3Si2O5(OH)4 rods exhibited vertically oriented nanosheets, resulting in a substantial increase in the specific surface area (from 2.24 m2/g to 178.4 m2/g). Subsequently, a CdS/Ni3Si2O5(OH)4 composite photocatalyst (CdS/NS) was prepared using a chemical deposition method. CdS was uniformly loaded onto the surface of the Ni3Si2O5(OH)4 nanosheets, successfully forming a heterojunction with Ni3Si2O5(OH)4. The CdS/NS photocatalyst in the presence of lactic acid as a sacrificial agent demonstrated an impressive H2 production rate of 4.05 mmol h−1 g−1, around 40 times higher than pure CdS. The photocorrosion of CdS was effectively solved after loading. After four cycles, the performance of CdS/NS remained stable, showing the potential for sustainable applications. After photoexcitation, electrons moved from Ni3Si2O5(OH)4 to the valence band of CdS, where they interacted with the holes via an enhanced interface contact. Simultaneously, electrons in CdS transitioned to its conduction band, facilitating hydrogenation. The enhanced performance was attributed to the improved CdS dispersion by Ni3Si2O5(OH)4 loading and efficient photogenerated carrier separation through the heterojunction formation. This work provides new perspectives for broadening the applications of mineral materials and developing heterojunction photocatalysts with good dispersibility and recyclability.

A kidney-targeted chitosan-melanin nanoplatform for alleviating diabetic nephropathy through modulation of blood glucose and oxidative stress

Diabetic nephropathy (DN) is a serious complication in patients with diabetes, whose expansion process is closely related to oxidative stress caused by hyperglycemia. Herein, we report a chitosan-targeted dagliflozin-loaded melanin nanoparticle (CSMDNPs) that can selectively accumulate in injured kidneys, reduce blood glucose, and alleviate the oxidative stress-induced damage. CSMDNPs possess good dispersion and physiological stability, responsive release at acidic pH, and strong scavenging activities for various reactive oxygen and reactive nitrogen radicals. Moreover, in vitro experiments confirm that CSMDNPs have good biocompatibility, enable targeted uptake in NRK-52E renal tubular cells, and also well alleviate high glucose-induced oxidative stress. In the STZ-induced DN model, CSMDNPs exhibit high targeting distribution and retention in the damaged kidneys of DN mice according to photoacoustic imaging. At the end of CSMDNPs treatment, DN mice show a decrease in fasting blood glucose and a return to near-normal urine and blood indices. H&E, PAS, and masson pathological staining also indicates that CSMDNPs significantly inhibit the expansion of renal interstitium, glycogen, and collagen deposition, showing excellent therapeutic effects. In addition, melanin acts as both drug carrier and antioxidant without exogenous carrier introduction, exhibiting better biosafety and translational prospects.

Facile synthesis of manganese-hafnium nanocomposites for multimodal MRI/CT imaging and in vitro photodynamic therapy of colon cancer

Precise diagnosis of complex and soft tumors is challenging, which limits appropriate treatment options to achieve desired therapeutic outcomes. However, multifunctional nano-sized contrast enhancement agents based on nanoparticles improve the diagnosis accuracy of various diseases such as cancer. Herein, a facile manganese-hafnium nanocomposites (Mn3O4-HfO2 NCs) system was designed for bimodal magnetic resonance imaging (MRI)/computed tomography (CT) contrast enhancement with a complimentary function of photodynamic therapy. The solvothermal method was used to fabricate NCs, and the average size of Mn3O4 NPs and Mn3O4-HfO2 NCs was about 7 nm and 15 nm, respectively, as estimated by TEM. Dynamic light scattering results showed good dispersion and high negative (-33 eV) zeta potential, indicating excellent stability in an aqueous medium. Mn3O4-HfO2 NCs revealed negligible toxic effects on the NCTC clone 929 (L929) and mouse colon cancer cell line (CT26), demonstrating promising biocompatibility. The synthesized Mn3O4-HfO2 NCs exhibit significant enhancement in T1-weighted magnetic resonance imaging (MRI) and X-ray computed tomography (CT), indicating the appropriateness for dual-modal MRI/CT molecular imaging probes. Moreover, ultra-small Mn3O4-HfO2 NCs show good relaxivities for MRI/CT. These nanoprobes Mn3O4-HfO2 NCs further possessed outstanding reactive oxygen species (ROS) generation ability under minute ultraviolet light (6 mW·cm−2) to ablate the colon cancer cells in vitro. Therefore, the designed multifunctional Mn3O4-HfO2 NCs were ideal candidates for cancer diagnosis and photodynamic therapy.

Preparation of etoposide liposomes for enhancing antitumor efficacy on small cell lung cancer and reducing hematotoxicity of drugs

Etoposide (VP16) is commonly used in the treatment of small cell lung cancer (SCLC) in clinical practice. However, severe adverse reactions such as bone marrow suppression toxicity limit its clinical application. Although several studies on VP16 liposomes were reported, no significant improvement in bone marrow suppression toxicity has been found, and there was a lack of validation of animal models for in vivo antitumor effects. Therefore, we attempted to develop a PEGylated liposomal formulation that effectively encapsulated VP16 (VP16-LPs) and evaluated its therapeutic effect and toxicity at the cellular level and in animal models. First, we optimized the preparation process of VP16-LPs using an orthogonal experimental design and further prepared them into freeze-dried powder to improve storage stability of the product. Results showed that VP16-LPs freeze-dried powder exhibited good dispersibility and stability after redispersion. In addition, compared to marketed VP16 injection, VP16-LPs exhibited sustained drug release characteristics. At the cellular level, VP16-LPs enhanced the cellular uptake of drugs and exhibited strong cytotoxic activity. In animal models, VP16-LPs could target and aggregate in tumors and exhibit a higher anti-tumor effect than VP16-injection after intravenous injection. Most importantly, hematological analysis results showed that VP16-LPs significantly alleviated the bone marrow suppression toxicity of drug. In summary, our study confirmed that PEGylated liposomes could enhance therapeutic efficacy and reduce toxicity of VP16, which demonstrated that VP16-LPs had enormous clinical application potential.