Nanoparticles insert a three dimensional cavity structure of proteins for function inhibition: The Case of CeO2 and SARS-CoV-2

The selective interaction of nanomaterials with proteins for protein function suppression has been reported. However, whether the nanomaterials could be used to target a three-dimensional (3D) structure of proteins for the consequent function inhibition is not defined. When SARS-CoV-2 binds to the host cell surface ACE2 receptor, the spike protein trimer changes to an "Open State" which forms a 5 nm cavity structure, consequently exposing the receptor binding domain (RBD) for the following viral infection. We found that the 3 nm cerium oxide nanoparticles (CeO2@3) showed a better anti-SARS-CoV-2 effect than 30 nm cerium oxide nanoparticles (CeO2@30). We performed a series of experiments and demonstrated that the CeO2@3 could target the 5 nm spike protein trimer cavity and tightly bind with the RBD, thus effectively blocking the following virus-cell interaction and rendering CeO2@3 as an effective anti-viral agent. As all coronaviruses possess similar spike protein structures as homologous proteins, CeO2@3 can be used as a broad-sperm anti-coronavirus nanodrug candidate by targeting the spike protein 3D structure. This work, for the first time, demonstrated that rationally engineered inorganic nanomaterials can be used to specifically target a 3D structure of a certain protein for function inhibition, thus providing a novel methodological approach and paving the way for future molecular targeting nanodrug candidate design.This study was supported by the National Key R&D Program of China (2021YFE0113000, 2022YFC2303700), the National Natural Science Foundation of China (82261138630, 32171390, 32201154, 51872318, 32371469, 31971322), the Natural Science Foundation of Guangdong Province (2023A0505050123, 2023B1515020104, 2022A1515010549), the International Partnership Program (IPP) of CAS (172644KYSB20210011), Key Collaborative Research Program of the Alliance of International Science Organizations (ANSO-CR-KP-2022-01), the CAS President's International Fellowship Initiative (2020VBA0022), the NanoProCov project of the Austrian Academic Exchange Service (OeAD, grant CN06/2021), and the SmartCERIALS project of the Austrian Research promotion Agency (FFG, grant 890610).Peer reviewe

Kinetic and Mechanistic Study on Catalytic Decomposition of Hydrogen Peroxide on Carbon-Nanodots/Graphitic Carbon Nitride Composite

The metal-free CDots/g-C3N4 composite, normally used as the photocatalyst in H2 generation and organic degradation, can also be applied as an environmental catalyst by in-situ production of strong oxidant hydroxyl radical (HO·) via catalytic decomposition of hydrogen peroxide (H2O2) without light irradiation. In this work, CDots/g-C3N4 composite was synthesized via an electrochemical method preparing CDots followed by the thermal polymerization of urea. Transmission electron microscopy (TEM), X-Ray diffraction (XRD), Fourier Transform Infrared (FTIR), N2 adsorption/desorption isotherm and pore width distribution were carried out for characterization. The intrinsic catalytic performance, including kinetics and thermodynamic, was studied in terms of catalytic decomposition of H2O2 without light irradiation. The second-order rate constant of the reaction was calculated to be (1.42 ± 0.07) × 10−9 m·s−1 and the activation energy was calculated to be (29.05 ± 0.80) kJ·mol−1. Tris(hydroxymethyl) aminomethane (Tris) was selected to probe the produced HO· during the decomposing of H2O2 as well as to buffer the pH of the solution. The composite was shown to be base-catalyzed and the optimal performance was achieved at pH 8.0. A detailed mechanism involving the adsorb-catalyze double reaction site was proposed. Overall, CDots/g-C3N4 composite can be further applied in advanced oxidation technology in the presence of H2O2 and the instinct dynamics and the mechanism can be referred to further applications in related fields

Impaired pulmonary function and associated factors in the elderly with tuberculosis on admission: a preliminary report

Abstract Background Pulmonary tuberculosis (TB) can impair pulmonary function (PF), especially in the elderly. The risk factors associated with the severity of PF impairment in the elderly with pulmonary TB remain unclear. Hence, this retrospective study aimed to address this issue to help improve the management of TB in the elderly population. Methods From January 2019 to February 2022, the elderly who were admitted to our hospital for pulmonary TB and underwent PF testing were included in this analysis. The forced expiratory volume in one second percent of predicted (FEV1% predicted) and clinical characteristics were collected and analyzed retrospectively. The extent of impaired PF was then categorized based on the FEV1% predicted and classified as grade 1–5. Logistic regression analysis was used to analyze the risk factors for impaired PF. Results A total of 249 patients who met the enrollment criteria were included in this analysis. According to the results of FEV1% predicted, all patients were classified as grade 1 (n = 37), grade 2 (n = 46), grade 3 (n = 55), grade 4 (n = 56), or grade 5 (n = 55). Statistical analysis showed that albumin (adjusted odds ratio (aOR) = 0.928, P = 0.013), body mass index (BMI) < 18.5 kg/m2 (aOR = 4.968, P = 0.046), lesion number ≥ 3 (aOR = 4.229, P < 0.001), male (aOR = 2.252, P = 0.009), respiratory disease (aOR = 1.669, P = 0.046), and cardiovascular disease (aOR = 2.489, P = 0.027) were related to the impairment of PF. Conclusions PF impairment is common in the elderly with pulmonary TB. The male sex, BMI < 18.5 kg/m2, lesion number ≥ 3, hypoproteinemia, and respiratory and cardiovascular comorbidities were identified as risk factors for significant PF impairment. Our findings highlight the risk factors associated with PF impairment, which may be helpful to improve the current management of pulmonary TB in the elderly to save their lung function

Kinetic and Mechanistic Study on Catalytic Decomposition of Hydrogen Peroxide on Carbon-Nanodots/Graphitic Carbon Nitride Composite

The metal-free CDots/g-C3N4 composite, normally used as the photocatalyst in H2 generation and organic degradation, can also be applied as an environmental catalyst by in-situ production of strong oxidant hydroxyl radical (HO·) via catalytic decomposition of hydrogen peroxide (H2O2) without light irradiation. In this work, CDots/g-C3N4 composite was synthesized via an electrochemical method preparing CDots followed by the thermal polymerization of urea. Transmission electron microscopy (TEM), X-Ray diffraction (XRD), Fourier Transform Infrared (FTIR), N2 adsorption/desorption isotherm and pore width distribution were carried out for characterization. The intrinsic catalytic performance, including kinetics and thermodynamic, was studied in terms of catalytic decomposition of H2O2 without light irradiation. The second-order rate constant of the reaction was calculated to be (1.42 ± 0.07) × 10−9 m·s−1 and the activation energy was calculated to be (29.05 ± 0.80) kJ·mol−1. Tris(hydroxymethyl) aminomethane (Tris) was selected to probe the produced HO· during the decomposing of H2O2 as well as to buffer the pH of the solution. The composite was shown to be base-catalyzed and the optimal performance was achieved at pH 8.0. A detailed mechanism involving the adsorb-catalyze double reaction site was proposed. Overall, CDots/g-C3N4 composite can be further applied in advanced oxidation technology in the presence of H2O2 and the instinct dynamics and the mechanism can be referred to further applications in related fields