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Kunzhao Huang,* Xiaoyuan Yi,* Huaying Xie, Jianzhang Luo, Qingyu Zeng, Feifei He, Liyan Wang Digestive Department, The Affiliated Hospital of Guilin Medical College, Guilin, 541001, People’s Republic of China*These authors contributed equally to this workCorrespondence: Liyan Wang, Digestive Department, The Affiliated Hospital of Guilin Medical College, Guilin, 541001, People’s Republic of China, Tel +86-15295953938, Email 168wangliyan@163.comPurpose: Ferroptosis is a regulated form of cell death characterized by iron-dependent accumulation of associated lipid peroxides (LPO), which can induce cell death when a certain level is reached. However, the extremely complex tumor microenvironment (TME) has the characteristics of antioxidant, even if it induces ferroptosis of tumor cells, its killing effect on tumor cells is still very limited. To solve this problem, we constructed a novel nanomaterials (GOx/EC@Fe3O4@CCM). We evaluated the anticancer effect of this nanomaterial in inhibiting tumor growth through comprehensive in vitro and in vivo experiments.Methods: We successfully synthesized GOx/EC@Fe3O4 by one-pan synthesis method, then coated the Hepatocellular carcinoma cell membrane on its surface by co-extrusion technology, and finally synthesized the GOx/EC@Fe3O4@CCM nanoplatforms. We characterized the compounds in terms of morphology, particle size, and Zeta potential. In addition, we also studied the anti-tumor effect of GOx/EC@Fe3O4@CCM nanoplatforms from the following aspects, including the performance test of the nanoplatform, the intracellular effect of the nanoplatform, the anti-tumor effect in vitro, the intracellular ROS analysis, the intracellular effect of EC, and the anti-tumor effect in vivo.Results: The iron-based carriers in GOx/EC@Fe3O4@CCM nanoplatforms are released and produce ferrous ions (Fe2+) in an acidic environment. Due to the limitation of the endogenous level of hydrogen peroxide (H2O2), we introduced GOx into the TME or tumor cells. Under the catalysis of GOx, glucose reacted rapidly to produce a large amount of H2O2, which then combined with Fe2+ to produce a large number of Hydroxyl radical (·OH). Its toxicity leads to dysfunction of cell membrane and organelles, and then causes cell damage. EC inhibits Nuclear factor erythroid 2-related factor 2 (Nrf2) in cancer cells, which effectively down-regulates downstream gene products, including NAD(P)H quinone oxidoreductase 1 (NQO1) and heme oxygenase 1 (HMOX1). A series of chain reactions reduce the escape effect of oxidative stress (OS) and effectively maintain a high level of intracellular oxidation. Furthermore, it induces sustained and intense ferroptosis in tumor cells. Finally, the use of cancer cell membrane modified nanoplatforms due to the homology of membrane protein components improves the tumor cell targeting of the nanoplatforms, showing significant tumor cell inhibition and killing effect in vivo.Conclusion: The results showed that the GOx/EC@Fe3O4@CCM nanoplatforms successfully induced significant ferroptosis of Hepatocellular carcinoma cells through a cascade effect, and finally effectively promoted cancer cell regression. Keywords: ferroptosis, mesoporous Fe3O4, glucose oxidase, ethyl carbamate, Nrf2

Dopamine (DA) detection is significant for the prevention of unfavorable neuronal illness. However, the detection of DA with low concentration still face tremendous challenges. In this study, highly ordered mesoporous Fe 3 O 4 materials were synthesized as a biosensor by using mesoporous silica KIT-6 with different aging temperature as hard template. The ordered mesoporous Fe 3 O 4 with high surface area modified glassy carbon electrode shows the high sensitivity for detecting DA. Fe 3 O 4 -40 mesoporous material modified electrode has the highest catalytic activity to DA with a sensitivity of 0.053 nA nM−1 and a detection limit of 0.8 nM (S/N = 3). The results indicating that the mesoporous Fe 3 O 4 material modified electrode exhibits high sensitivity to determine DA at low levels, which can be used for DA real-time monitoring in neutral biological media. fx1 [ABSTRACT FROM AUTHOR]

Mesoporous Fe3O4 nanoparticles were synthesized by a solvothermal method, via a mixed solvent of ethylene glycol (EG) and deionized water, using iron chloride and urea as the precursors. The phase, morphology, and pore structure are investigated by the characterization of X-ray diffraction (XRD), transmission electron microscopy (TEM), and N2 isotherm adsorption–desorption. The results show that the amount of water in the mixed solvent plays vital role in controlling the size of Fe3O4 nanoparticles, specific surface area, and pore size. Additionally, solid Fe3O4 nanospheres were prepared using only EG as solvent, while α-Fe2O3 nanosized polyhedrals were obtained with only water as solvent. The mesoporous Fe3O4 nanoparticles show a ferromagnetic behavior, with saturation magnetizations (Ms) of 78–82 emu g− 1 and coercivities (Hc) ranging from 13–58 Oe. The α-Fe2O3 nanoparticles also exhibit a weak-ferrimagnetic character, with a remanent magnetization (Mr) of 0.24 emu g− 1, and Hc of 558 Oe. [ABSTRACT FROM AUTHOR]

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The focus of this study was the ultrasound-assisted degradation of sildenafil by three-dimensional (3D) mesoporous Fe 3 O 4 with large surface undulations. The influence of various factors, such as pH, H 2 O 2 dosage, and ultrasonic (US) power, on sildenafil decomposition was examined. The maximum difference in the undulations of Fe 3 O 4 was observed with a synthesis time of 8 h (40 nm). The optimal experimental conditions were 10 mmol H 2 O 2 , pH 3, and US intensity of 300 W, and the maximum kinetic constant (0.23903 min−1) was achieved under these experimental conditions. The 3D spherical Fe 3 O 4 (8 h) catalyst almost completely removed 50 mg L−1 of sildenafil within 120 min, and AFM characterizations revealed that the Fe 3 O 4 catalyst had a piezoelectric response of 33 pm/V. These data demonstrate that a piezoelectric catalyst with large surface undulations can substantially enhance the US cavitation effect. Free-radical experiments indicated that •OH radicals were the main active species during the process. Based on the quantitative structure–activity relationship results obtained under neutral conditions, the US–Fenton–piezoelectric process reduced the ecotoxicity and improved the biodegradability of sildenafil. [Display omitted] • The synthesized 3D spherical Fe 3 O 4 material enhanced the synergistic effects of ultrasound and piezoelectricity. • DFT computational analysis of sildenafil was performed. • Ultrasonic-assisted degradation of sildenafil with 91 % removal rate and 54 % TOC removal rate was achieved in 120 min. [ABSTRACT FROM AUTHOR]

A novel controlled release system-based antigen-response electrochemical immunosensor was developed for detecting cardiac troponin I (cTnI) by using aminated polystyrene microsphere (APSM) as molecular gate and Fe 3 O 4 as nanocontainer. The amino functionalized mesoporous Fe 3 O 4 (Fe 3 O 4 –NH 2) was used to load cobalt phthalocyanine nanoparticles (CoPc NPs) and further capture the antibody of cTnI (Ab) to form Fe 3 O 4 -Ab. In addition, APSM was introduced to cap on the mesoporous of Fe 3 O 4 -Ab by electrostatic interaction. With the addition of cTnI, APSM was separated from Fe 3 O 4 -Ab due to the specific binding of antibody to antigen. Then, CoPc NPs were released from the mesoporous. The experimental results revealed that CoPc NPs showed superb catalytic performance when catalyzing hydrogen peroxide (H 2 O 2) reduction in phosphate buffer saline (PBS). The current responses are correlated with the amount of cTnI. Under the best conditions, a broad linear range from 1.0 pg/mL to 100 ng/mL with a low detection limit of 0.39 pg/mL (S/N = 3) was obtained. The immunosensor also shows good reproducibility and selectivity, which endows its broad application prospect in clinical research. • A novel controlled release protocol was developed for detection of AFP. • Aminated polystyrene microspheres were replaced by cTnI by antigen-antibody bind. • Released CoPc NPs showed superb current response. • A low detection limit of 0.39 pg/mL was obtained. [ABSTRACT FROM AUTHOR]

Abstract: Mesoporous magnetite (Fe3O4) was successfully synthesized on a large scale by direct pyrolysis of ferric nitrate-EG (EG=ethylene glycol) gel in a one-end closed horizontal tube furnace in the air without using any template, additions, and carrier gas. The as-synthesized mesoporous Fe3O4 were characterized by powder X-ray diffraction (XRD), infrared spectra (IR), transmission electron microscopy (TEM), high-resolution transmission electron microscopy (HRTEM), selected area electron diffraction (SAED), Brunauer–Emmett–Teller (BET), Barrett–Joyner–Halenda (BJH), and thermal gravimetric analysis (TGA). Results from TEM showed that the as-obtained Fe3O4 has mesoporous structure formed by the loose agglomeration of nanoparticles with diameter of about 6nm, which was also confirmed by small-angle XRD and nitrogen adsorption analysis. Furthermore, vibrating sample magnetometer (VSM) measurements indicated that the saturated magnetization of the as-obtained mesoporous Fe3O4 was ferromagnetic with the saturation magnetization (Ms) and coercivity (Hc) of 46emu/g and 136Oe, respectively. In addition, a possible growth mechanism of mesoporous Fe3O4 was also discussed. [ABSTRACT FROM AUTHOR]